The first Early Cretaceous representative of the fly family Tipulidae from the lower Barremian dysodiles of Lebanon (Diptera)

Leptotarsus reyi sp. nov., first representative of the family Tipulidae from the Lower Cretaceous of Lebanon, is characterised, described and illustrated from the Early Barremian dysodile of Jdeidet Bkassine, South Lebanon.

New stem-anisopteran dragonflies in the Jurassic of China (Odonata: Epiproctophora)

The odonatan asiopterid Turanopteron sinensis sp. nov. and the juragomphid Oxfordgomphus trescellulae gen. et sp. nov. are described on the basis of two new fossil wings from the Middle-Upper Jurassic of Henan Province in China. These taxa belong to ancient, Toarcian epiproctophoran stem groups of Anisoptera Selys, 1854. They show important affinities with taxa from the Karatau entomofauna in Kazakhstan. These groups progressively decrease and were replaced by more modern clades of Anisoptera during the Late Jurassic.

Revision of <em>Sinomesuropetala daohugensis</em> Boudet, Nel & Huang, 2023 (Odonata: Aeshnoptera: Mesuropetalidae)

The mesuropetalid dragonfly Sinomesuropetala daohugensis Boudet, Nel & Huang, 2023, is here revised based on a new well-preserved dragonfly from the Haifanggou Formation of Inner Mongolia, northeastern China. The new specimen allows us to complete the forewing characters of this species, showing the close relationship of Sinomesuropetala Boudet, Nel & Huang, 2023 with Mesuropetala Handlirsch, 1906. The mesuropetalid dragonflies are currently recorded from the Late Jurassic and Lower Cretaceous deposits of east Asia, East Central South Europe, and southern America, indicating the wide distribution and the possible long-distance migration ability of some basal aeshnopteran dragonflies during these epochs.

The second North American fossil horntail wood-wasp (Hymenoptera: Siricidae), from the early Eocene Green River Formation

Eoteredon lacoi gen. et sp. nov., is described from the early Eocene Green River Formation in Wyoming, the second fossil siricid genus and species described from North America. We propose Eoteredon as sister to the genus Teredon, whose sole species is one of the rarest of extant Siricidae. The majority of siricids today inhabit temperate Northern Hemisphere forests; Teredon cubensis, however, is one of its few species that live in megathermal tropical lowlands. The Eocene forest that Eoteredon inhabited had a mesothermal to megathermal climate. We place Eoteredon in the context of broad Cenozoic climate change.

Biochemical responses revealed in an amphibian species after exposure to a forgotten contaminant: An integrated biomarker assessment

Vanadium is a metal whose toxicity towards terrestrial and aquatic species has been under-reported to date.. The biochemical responses of vanadium in amphibian species have not been determined. To establish the effects of vanadium (V) on exposed adult Xenopus laevis, acute and chronic exposures were conducted, and biomarker analyses were performed on liver and muscle tissues from exposed frogs. Biomarkers of exposure, such as acetylcholinesterase (AChE) and metallothioneins (MT), were analysed. Biomarkers of effect were also analysed to determine possible increases in reactive oxygen species (ROS), and the effect of the exposure on the energy balance in the organisms. These included superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), protein carbonyls (PC), malondialdehyde (MDA), and cellular energy allocation (CEA) (energy available, energy consumption, lipids, proteins and glucose). In acute exposures, the energy balances in organisms were distinctly affected, possibly due to insulin mimetic properties of V. In chronic exposures, MT, AChE, SOD, CAT and GSH responses were more pronounced. Although AChE is generally inhibited by pollutant exposure, in this study, it was stimulated. There were significant inhibitions of SOD and CAT, previously observed in frog species. PC levels increased in the highest acute exposure concentration, indicating protein damage. The IBR.v2 revealed the biochemical responses of V more effectively than traditional statistical analysis.

A comparison of water quality and macroinvertebrate community structure in endorheic depression wetlands and a salt pan in the Gauteng province, South Africa

Depression wetlands (colloquially referred to in South Africa (SA) as pans) are found worldwide and primarily occur in arid regions including North and South America, southern and central Africa and southern and western Australia. Surface water resources in SA, and specifically in Gauteng, are under pressure from urbanisation, poor agricultural practices and untreated mining and industrial effluent. Research of these wetlands will benefit the development of health assessment tools for these unique aquatic resources. The aim of this project was to determine the water quality and macroinvertebrate community structure for each perennial pan during consecutive dry and wet seasons and to establish a possible comparison between these pans that can be used as a baseline for future research on pans. The sampled pans in Gauteng presented higher TDS, Cl and Mg results compared to other South African studies, and similar SO₄ results to pans in the Mpumalanga province. Ammonia, Al and Zn results of all pans through all sampling events exceed the Target Water Quality Range (TWQR) for aquatic ecosystems of the Water Quality Guidelines (WQG) from the Department of Water and Sanitation (DWS). The water quality from selected systems is suitable for livestock watering based on the DWS TWQR. Macroinvertebrate species of all sampled pans were mostly low water quality tolerant species with a predator dominant community structure. Seasonal variation of species was evident. Macroinvertebrate families found in the wet season include Hydrophilidae, Aeshnidae, Pleiidae, Ephemeroptera, Belostomatidae and Notonectidae. Families found in the dry season include Planaridae, Dysticidae, Hirudinidae and Daphnidae. Graphical representation of ordination analyses with Canoco version 5 (Ter Braak and Šmilauer 2012) indicated that TDS, temperature, pH, sulphates and hardness are strong drivers of the existing macroinvertebrate community in most of the pans.

Eodromyia pumilio gen. et sp. nov., a new empidoid fly from the Earliest Eocene amber of France (Diptera: Hybotidae: Tachydromiinae)

Eodromyia pumilio gen. et sp. nov., is described as the oldest record of the hybotid tribe Drapetini, from the Lowermost Eocene amber of Oise (France). It differs from described extant genera in the tribe, among other characters, by the complete absence of crossvein bm-cu.

A new species of <i>Ferneiella</i> from the Eocene French amber (Diptera: Scatopsidae)

We describe the first fossil representative of the genus Ferneiella, F. gallica sp. nov., in the earliest Eocene Oise amber.

Development of an electrochemical surface-enhanced Raman spectroscopy (EC-SERS) aptasensor for direct detection of DNA hybridization

Rapid detection of disease biomarkers at the patient point-of-care is essential to timely and effective treatment. The research described herein focuses on the development of an electrochemical surface-enhanced Raman spectroscopy (EC-SERS) DNA aptasensor capable of direct detection of tuberculosis (TB) DNA. Specifically, a plausible DNA biomarker present in TB patient urine was chosen as the model target for detection. Cost-effective screen printed electrodes (SPEs) modified with silver nanoparticles (AgNP) were used as the aptasensor platform, onto which the aptamer specific for the target DNA was immobilized. Direct detection of the target DNA was demonstrated through the appearance of SERS peaks characteristic for adenine, present only in the target strand. Modulation of the applied potential allowed for a sizeable increase in the observed SERS response and the use of thiol back-filling prevented non-specific adsorption of non-target DNA. To our knowledge, this work represents the first EC-SERS study of an aptasensor for the direct, label-free detection of DNA hybridization. Such a technology paves the way for rapid detection of disease biomarkers at the patient point-of-care.

Skleroptera, a new order of holometabolous insects (Insecta) from the Carboniferous

A new order of holometabolan insects is proposed for Stephanastus polinae Kirejtshuk et Nel, 2013 from the Upper Carboniferous of Allier, France (Gzhelian, Commentry) (Nel et al., 2013). It is considered a member of the superorder Coleopterida. It shares with the order Coleoptera sclerotised forewings, which demonstrate a simple and somewhat reduced Sc, a simple and concave RP, a convex RA, the M less convex than R and CuA, M also simple and basally fused with CuA (putative synapomorphy), but distally separating from it; stem of M+Cu well separated from R, the coxae do not project and the trochanters are short. The new order Skleroptera ordo nov. differs from the orders Coleoptera and Strepsiptera in the structure of the thoracic sclerites and venation of the forewings, particularly in the following character combination: the absence of lateral carina on the prothorax, the narrow separation of the bases of its forewings, the very narrow anal region of the forewings that widen apically and the absence of a sub-marginal anal (adsutural) vein going along the entire posterior margin of the tegmina. These unique characters of Stephanastus Kirejtshuk et Nel, 2013 suggest that this individual was somewhat laterally compressed (like some orthopteroids). This represents also an essential difference from body ground plan of the Coleoptera in general. It is hypothesized that the position of the new order within the superorder Coleopterida at the subclade level is as follows: Skleroptera + (Coleoptera [probably including Umenocoleidae sensu stricto] +Strepsiptera).

High acceptability of a vaginal ring intended as a microbicide delivery method for HIV prevention in African women

Vaginal rings (VRs) are new methods for continuous delivery of microbicides. This is the first study to quantitatively and qualitatively explore the acceptability of rings in Africa: 157 HIV-negative, sexually active women aged 18-35 used a placebo silicone elastomer ring for 12 weeks. They completed product acceptability questionnaires every 4 weeks. We conducted 6 exit focus group discussions with a subset of 48 women and 19 in-depth interviews with male partners. Retention in the study was high (97 %). Initial insertion at the clinic was successful on first attempt for 81 % of participants. Most women were comfortable using the ring, and very few (≤2 %) could feel it during daily activities or had ring-related physical or emotional problems. In the qualitative interviews many participants reported that they initially had concerns about using the ring. However, only a minority of women actually reported concerns with the ring during the study. The most frequent concern was that the ring would get lost inside the body (20 %), and this was significantly correlated with study site, frequently thinking about the ring and reporting that the ring was not very easy to remove. Qualitative data suggest that informants grew to like the ring because it felt securely placed, was unnoticeable during daily activities, and felt "normal" during sex. The ring appeared to be highly acceptable for women and men. Initial concerns with this novel method suggest a need for enhanced product counseling when VRs are introduced.

The oldest representatives of the family Coccinellidae (Coleoptera: Polyphaga) from the Lowermost Eocene Oise amber (France)

In the paper two new species of the genus Rhyzobius Stephens, 1829 (R. antiquus sp. nov. and R. gratiosus sp. nov.) and one new species of the genus Nephus Mulsant 1846 (N. subcircularis sp. nov. without a certain subgeneric placement) from the Lowermost Eocene amber of Oise are described. A short review of known fossil records of the family Coccinellidae is given.

No time to lose--high throughput screening to assess nanomaterial safety

Nanomaterials hold great promise for medical, technological and economical benefits. Knowledge concerning the toxicological properties of these novel materials is typically lacking. At the same time, it is becoming evident that some nanomaterials could have a toxic potential in humans and the environment. Animal based systems lack the needed capacity to cope with the abundance of novel nanomaterials being produced, and thus we have to employ in vitro methods with high throughput to manage the rush logistically and use high content readouts wherever needed in order to gain more depth of information. Towards this end, high throughput screening (HTS) and high content screening (HCS) approaches can be used to speed up the safety analysis on a scale that commensurate with the rate of expansion of new materials and new properties. The insights gained from HTS/HCS should aid in our understanding of the tenets of nanomaterial hazard at biological level as well as assist the development of safe-by-design approaches. This review aims to provide a comprehensive introduction to the HTS/HCS methodology employed for safety assessment of engineered nanomaterials (ENMs), including data analysis and prediction of potentially hazardous material properties. Given the current pace of nanomaterial development, HTS/HCS is a potentially effective means of keeping up with the rapid progress in this field--we have literally no time to lose.

New genus and species of subfamily Trinodinae (Coleoptera, Polyphaga, Dermestidae) from Lowermost Eocene French amber

In the paper six new species of the genus Oisenodes gen. nov. (Dermestidae, Trinodinae, Trinodini) are described: O. azari sp. nov., O. clavatus sp. nov., O. gallicus sp. nov., O. metepisternalis sp. nov., O. oisensis sp. nov. and O. transversus sp. nov. A new tribe Trinoparvini Hava, trib. nov. is established for the recent genus Trinoparvus Háva, 2004. Short review of known fossil records of the subfamily Trinodinae is given.

Bilateral periventricular nodular heterotopia – neonatal cranial ultrasound

A female neonate was delivered at 30 weeks’ gestation to a mother with suspected bilateral periventricular nodular heterotopia (PNH) on computed tomography brain scan. Antenatal ultrasound (US) performed at 28 weeks’ gestation showed mild lateral cerebral ventricle dilatation, but no other fetal anomalies. Clinical examination revealed mild dysmorphic features: facial and skull asymmetry, square-shaped ears, and long tapering fingers. Chromosomal analysis showed a 46XX karyotype.

Inhaled ultrafine particulate matter affects CNS inflammatory processes and may act via MAP kinase signaling pathways

In addition to evidence that inhalation of ambient particulate matter (PM) can increase cardiopulmonary morbidity and mortality, the brain may also constitute a site adversely effected by the environmental presence of airborne particulate matter. We have examined the association between exposure to PM and adverse CNS effects in apolipoprotein E knockout (ApoE-/-) mice exposed to two levels of concentrated ultrafine particulate matter in central Los Angeles. Mice were euthanized 24h after the last exposure and brain, liver, heart, lung and spleen tissues were collected and frozen for subsequent bioassays. There was clear evidence of aberrant immune activation in the brains of exposed animals as judged by a dose-related increase in nuclear translocation of two key transcription factors, NF-kappaB and AP-1. These factors are involved in the promotion of inflammation. Increased levels of glial fibrillary acidic protein (GFAP) were also found consequent to particulate inhalation suggesting that glial activation was taking place. In order to determine the mechanism by which these events occurred, levels of several MAP kinases involved in activation of these transcription factors were assayed by Western blotting. There were no significant changes in the proportion of active (phosphorylated) forms of ERK-1, IkB and p38. However, the fraction of JNK in the active form was significantly increased in animals receiving the lower concentration of concentrated ambient particles (CAPs). This suggests that the signaling pathway by which these transcription factors are activated involves the activation of JNK.

Haloperidol-induced dyskinesia is associated with striatal NO synthase suppression: reversal with olanzapine

The underlying pathophysiological basis of tardive dyskinesia (TD) remains speculative. Haloperidol (HP) inhibits neuronal nitric oxide (NO) synthase (NOS) activity in vitro, but has not to date been studied in an intact animal model. Recent animal studies have found that extrapyramidal dysfunction evoked by chronic HP is associated with suppression of striatal cyclic guanosine monophosphate (cGMP), as well as plasma nitrogen oxides. Striatal dopamine (DA) is central to motor control, while NO plays an important neuroregulatory role in striatal DA function. Recent case reports suggest that atypical antipsychotics, such as olanzapine (OLZ), may be effective in reversing TD. Here, rats treated with HP (1.5 mg/kg per day p.o.) for 28 days developed significant vacuous chewing movements (VCMs) together with significant suppression of striatal NOS activity. Acute challenge with OLZ (1 and 2 mg/kg i.p.) significantly reversed both HP-induced VCMs and suppression of striatal NOS activity. Therefore TD may involve attenuation of NO-mediated neuromodulation in the striatum. Reversal of VCMs and NOS suppression with OLZ suggests that disinhibition of striatal NOS activity may underlie the clinical benefit of OLZ in TD.

Microsatellite analysis of cryopreserved stallion semen stored on FTA paper

The aim of this study was to establish and validate a method to permit microsatellite analysis of DNA profiles obtained from frozen-thawed stallion sperm cells. This would provide reliable and accurate verification of the identification of a semen donor. Ejaculates from 5 pony stallions were collected, processed and frozen in 0.5 ml plastic straws. Aliquots of 100 microl of the frozen-thawed semen thus obtained were either placed directly, or diluted (1:10; 1:100; and 1:1000) and placed on slides of FTA paper. Similarly, blood samples obtained from each of the stallions were placed onto slides of FTA paper. A punch was removed from each sample after drying Each sample was mixed with FTA purification reagent, Dithiothreitol and Proteinase K before incubation and processing. All samples were processed with a set of 13 microsatellite markers. Further analysis permitted a comparison of the DNA profiles of the frozen-thawed semen and the blood samples. A full profile of markers was obtained from the 1:10 and 1:100 dilutions of the frozen-thawed semen samples as well as from the blood samples. The DNA profiles from the frozen-thawed semen and blood samples obtained from the stallions matched in all cases.

Evidence that oxidative stress-induced apoptosis by menadione involves Fas-dependent and Fas-independent pathways

Menadione (vitamin K3) a redox cycling quinone, is a clinically important chemotherapeutic agent. The objective of this study was to clarify the cytotoxic mechanisms by which menadione induces cell death in a lymphoblastoid cell line. Our results show that while the Jun kinase cascade and FasL expression may contribute to cell death at lower drug concentrations, a mitochondrial pathway dominates the cytotoxic effect at higher menadione concentrations. Menadione treatment clearly affected the mitochondrial function of Jurkat T cells by inducing a collapse of the inner transmembrane potential (DeltaPsi(m)) and a decrease in inner membrane mass, which could be completely reversed by N-acetylcysteine. Importantly, while a broad range of fmk-derived caspase inhibitors had potent effects on Fas-induced apoptosis, they failed to interfere in menadione cytotoxicity, indicating that menadione-induced cell death is predominantly Fas-independent. In addition, the mitochondrial changes coincided with ATP depletion. The failure in ATP production explains the occurrence of Fas-independent death events.

[Guidelines for implementation of tuberculosis education-learning]

This article is a follow up article of the previously published article "Die belewenis van die pasiënt en die verpleegkundige tydens tuberkulose-onderrig" and focuses on guidelines formulated on the basis of the research findings. These guidelines have been formulated in order to promote the nurse's knowledge and skills concerning: interpersonal relations, subject knowledge, a task versus patient orientated nursing approach, the motivation of the nurse, social support systems, stimulation of the patient's motivation, recovery from the patient's chest centredness and the acceptance of responsibility for his own health as well as the affirmation of the role of the nurse.

In vivo nasal challenge with diesel exhaust particles enhances expression of the CC chemokines rantes, MIP-1alpha, and MCP-3 in humans

Diesel exhaust particles (DEP) enhance allergic inflammation by increasing in vivo IgE and cytokine production in the human upper respiratory mucosa. CC chemokines have been shown to play an important role in inflammation. We examined whether DEP could alter the production of CC chemokines by cells residing in the human nasal mucosa. At both 6 and 24 h following intranasal DEP challenge, the levels of nasal RANTES, MIP-1alpha, and MCP-3 were significantly elevated compared to baseline. In contrast, DEP did not enhance levels of Eotaxin at any time, demonstrating that the action of DEP was not simply a global effect on all CC chemokines. Challenge with saline resulted in no significant change in expression of any chemokine at any time. Challenge with DEP also resulted in an increase in total cell counts in nasal lavage fluids. Increases in lymphocyte, monocyte/macrophage, and neutrophil cells were observed but there was no change in eosinophil cell numbers. In contrast, there was a significant enhancement of ECP protein levels in washes performed 6 to 24 h after DEP challenge. Elevated specific nasal chemokine expression following exposure to DEP likely participates in the inflammation, cellular infiltration, and increase in IgE observed in the absence of allergen.

Riglyne vir die toepassing in die onderrigleersituasie ten opsigte van tuberkulose

This article is a follow up article of the previoulsy published article “Die belewenis van die pasient en die verpleegkundige tydens tuberkulose-onderrig” and focuses on guidelines formulated on the basis of the research findings. These guidelines have been formulated in order to promote the nurse’s knowledge and skills concerning: interpersonal relations, subject knowledge, a task versus patient orientated nursing approach, the motivation of the nurse, social support systems, stimulation of the patient’s motivation, recovery from the patient’s chest centredness and the acceptance of responsibility for his own health as well as the affirmation of the role of the nurse.

Die belewenis van die pasiënt en die verpleegkundige tydens tuberkulose-onderrig

This article focused on the problem that patients suffering from tuberculosis often stop taking their prescribed medicine and become defaulters. Although various factors could possibly contribute to the non compliance of the patients, this research had focused only on the teaching-learning situation. The experience of both the primary health nurse and the patient suffering from tuberculosis, during the teaching-learning situation in tuberculosis education, has been explored and described within the context of the North West Province. Phenomenological interviews were conducted with primary health nurses and defaulting patients suffering from tuberculosis. Interviews were recorded on tape and transcribed verbatim. The method of content analysis was used. The research has proven that adult-teaching principles have not been established in the teaching-learning situation and that the parent-child ego state predominates in communication.

Induction of heme oxygenase-1 expression in macrophages by diesel exhaust particle chemicals and quinones via the antioxidant-responsive element

Diesel exhaust particles (DEP) contain organic chemicals that contribute to the adverse health effects of inhaled particulate matter. Because DEP induce oxidative stress in the lung and in macrophages, effective antioxidant defenses are required. One type of defense is through the expression of the antioxidant enzyme, heme oxygenase I (HO-1). HO-1 as well as phase II detoxifying enzymes are induced via antioxidant response elements (ARE) in their promoters of that gene. We show that a crude DEP total extract, aromatic and polar DEP fractions, a benzo(a)pyrene quinone, and a phenolic antioxidant induce HO-1 expression in RAW264.7 cells in an ARE-dependent manner. N-acetyl cysteine and the flavonoid, luteolin, inhibited HO-1 protein expression. We also demonstrate that the same stimuli induce HO-1 mRNA expression in parallel with the activation of the SX2 enhancer of that gene. Mutation of the ARE core, but not the overlapping AP-1 binding sequence, disrupted SX2 activation. Finally, we show that biological agents, such as oxidized 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphocholine, could also induce HO-1 expression via an ARE-dependent mechanism. Prior induction of HO-1 expression, using cobalt-protoporphyrin, protected RAW264.7 cells against DEP-induced toxicity. Taken together, these data show that HO-1 plays an important role in cytoprotection against redox-active DEP chemicals, including quinones.

Response differences between human CD4(+) and CD8(+) T-cells during CD28 costimulation: implications for immune cell-based therapies and studies related to the expansion of double-positive T-cells during aging

Since CD28 costimulation is critical for T-cell activation, there is great interest in CD28 as a target for immuntherapeutic approaches. We show that stimulation of human CD4(+) and CD8(+) T-cells differs in their responsiveness to stimulation with anti-CD3/CD28-coated beads, as surrogate antigen-presenting cells. While the CD4(+) subset responded with sustained proliferation, CD8(+) T-cells grew for a limited period only and failed to produce IL-2 beyond the first few days in culture. This decrease is accompanied with an increased rate of apoptosis in CD8(+) T-cells despite Bcl-x(L) expression. The CD8(+) but not the CD4(+) subset developed a reversible double-positive phenotype during CD28 costimulation. This finding may have some bearing on the appearance of double-positive T-cells in human peripheral blood. This double-positive subset was shown to undergo a statistically significantly increase during aging in humans. Taken together, the above data have important implications for immunotherapy and immune senescence.

[The experience of the patient and the registered nurse during tuberculosis education]

This article focused on the problem that patients suffering from tuberculosis often stop taking their prescribed medicine and become defaulters. Although various factors could possibly contribute to the non compliance of the patients, this research had focused only on the teaching-learning situation. The experience of both the primary health nurse and the patient suffering from tuberculosis, during the teaching-learning situation in tuberculosis education, has been explored and described within the context of the North West Province. Phenomenological interviews were conducted with primary health nurses and defaulting patients suffering from tuberculosis. Interviews were recorded on tape and transcribed verbatim. The method of content analysis was used. The research has proven that adult-teaching principles have not been established in the teaching-learning situation and that the parent-child ego state predominates in communication.

Inflammatory cytokines synergize with the HIV-1 Tat protein to promote angiogenesis and Kaposi's sarcoma via induction of basic fibroblast growth factor and the alpha v beta 3 integrin

The Tat protein of HIV-1, a transactivator of viral gene expression, is released by acutely infected T cells and, in this form, exerts angiogenic activities. These have linked the protein to the pathogenesis of Kaposi's sarcoma (KS), a vascular tumor frequent and aggressive in HIV-1-infected individuals (AIDS-KS). In this study, we show that a combination of the same inflammatory cytokines increased in KS lesions, namely IL-1 beta, TNF-alpha, and IFN-gamma, synergizes with Tat to promote in nude mice the development of angioproliferative KS-like lesions that are not observed with each factor alone. Inflammatory cytokines induce the tissue expression of both basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF), two angiogenic molecules highly produced in primary KS lesions. However, bFGF, but not VEGF, synergizes with Tat in vivo and induces endothelial cells to migrate, to adhere, and to grow in response to Tat in vitro. Tat angiogenic effects correlate with the expression of the alpha v beta 3 integrin that is induced by bFGF and binds the arginine-glycine-aspartic acid (RGD) region of Tat. In contrast, no correlation is observed with the expression of alpha v beta 5, which is promoted by VEGF and binds Tat basic region. Finally, KS lesion formation induced by bFGF and Tat in nude mice is blocked by antagonists of RGD-binding integrins. Because alpha v beta 3 is an RGD-binding integrin that is highly expressed in primary KS lesions, where it colocalizes with extracellular Tat on vessels and spindle cells, these results suggest that alpha v beta 3 competitors may represent a new strategy for the treatment of AIDS-KS.

Latex antigens: identification and use in clinical and experimental studies, including crossreactivity with food and pollen allergens

LEARNING OBJECTIVES

The purpose of this review is to introduce the reader to the range of latex allergens that have been identified by polypeptide sequencing. This knowledge is important for the assessment of clinical latex hypersensitivity, including crossreactivity with food and aeroallergens.

DATA SOURCES

Medline search and relevant publications and reviews from the English medical literature since 1989.

RESULTS

Of the more than 150 polypeptides in natural latex rubber, 35 or more can act as allergens and are recognized by IgE antibodies in the sera of latex-sensitive subjects. Complete or partial amino acid sequence data have now been obtained for 20 or more allergens, and have facilitated cloning of genes and development of allergen-specific antibodies. In latex-sensitive adults, hevein (Hev b6), rubber elongation factor (Hev b1) and Hev b5 are reported as major allergens, while in children with spina bifida, latex particle proteins are important allergens. Although incomplete, the data for finished latex products indicate that the number as well as diversity of latex antigens are limited compared with the allergen profile of natural rubber latex. Latex allergen sequence data allows epitope mapping, which establishes the molecular basis for understanding crossreactivity between latex, food, and aeroallergens.

CONCLUSION

The identification of latex allergens is paving the way for studying the molecular basis of immunoreactivity to these proteins, including crossreactivity with food and other allergens. The development of reagents to detect and measure antigen-specific responses will increase diagnostic specificity of allergic reactions to latex products.

Stress-induced Fas ligand expression in T cells is mediated through a MEK kinase 1-regulated response element in the Fas ligand promoter

T lymphocytes undergo apoptosis in response to a variety of stimuli, including exposure to UV radiation and gamma-irradiation. While the mechanism by which stress stimuli induce apoptosis is not well understood, we have previously shown that the induction of Fas ligand (FasL) gene expression by environmental stress stimuli is dependent on c-Jun N-terminal kinase (JNK) activation. Using inducible dominant-active (DA) JNK kinase kinase (MEKK1) expression in Jurkat cells, we map a specific MEKK1-regulated response element to positions -338 to -316 of the Fas ligand (FasL) promoter. Mutation of that response element abrogated MEKK1-mediated FasL promoter activation and interfered in stress-induced activation of that promoter. Using electrophoretic mobility shift assays, we demonstrate that activator protein 1 (AP-1) binding proteins, namely, activating transcription factor 2 (ATF2) and c-Jun, bind to the MEKK1 response element. Transient transfection of interfering c-Jun and ATF2 mutants, which lack the consensus JNK phosphorylation sites, abrogated the transcriptional activation of the FasL promoter, demonstrating the involvement of these transcription factors in the regulation of the FasL promoter. Taken together, our data indicate that MEKK1 and transcription factors regulated by the JNK pathway play a role in committing lymphocytes to undergo apoptosis by inducing FasL expression via a novel response element in the promoter of that gene.

Macrophage activation by polycyclic aromatic hydrocarbons: evidence for the involvement of stress-activated protein kinases, activator protein-1, and antioxidant response elements

Polycyclic aromatic hydrocarbons (PAH) contained in fossil fuel combustion particles enhance the allergic response to common environmental Ags. A key question is: what are molecular pathways in the immune system by which PAH and conversion products drive allergic inflammation? Circumstantial evidence suggests that macrophages are involved in PAH-induced responses. We demonstrate that a representative PAH, beta-napthoflavone (BNF), and a representative quinone metabolite, tert-butylhydroxyquinone (tBHQ), induce Jun kinase and p38 mitogen-activated protein kinase activities in parallel with the generation of activator protein-1 (AP-1) mobility shift complexes in THP-1 and RAW264.7 macrophage cell lines. Activation of mitogen-activated protein kinases was dependent on generation of oxidative stress, and could be inhibited by N-acetylcysteine. Another genetic response pathway linked to PAH is the antioxidant response element (ARE), which regulates expression of detoxifying enzymes. BNF and tBHQ activated a human ARE (hARE) reporter gene in RAW264.7 cells. Interestingly, bacterial lipopolysaccharide also induced hARE/chloramphenicol acetyltransferase activity. While the hARE core, GTGACTCAGC, contains a consensus AP-1 sequence (underlined), AP-1 was not required for hARE activation. This suggests that PAH and their conversion products operate via ARE-specific transcription factors in the immune system. BNF and tBHQ did, however, induce AP-1 binding to the hARE, while constitutively active Jun kinase interfered in hARE/chloramphenicol acetyltransferase activation. This suggests that AP-1 proteins negatively regulate the hARE. These data establish important activation pathways for PAH in the immune system and provide us with targets to modulate the effect of environmental pollutants on allergic inflammation.

The c-Jun N-terminal kinase cascade plays a role in stress-induced apoptosis in Jurkat cells by up-regulating Fas ligand expression

T lymphocytes undergo apoptosis in response to cellular stress, including UV exposure and gamma irradiation. However, the mechanism by which stress stimuli induce apoptosis is not well understood. While stress stimuli induce the activation of the c-Jun N-terminal kinase (JNK) pathway, it is not clear whether the JNK cascade is activated as a result of cell death or whether the cascade participates in inducing apoptosis. Using a Jurkat T cell line transfected with dominant active (DA)-mitogen-activated protein kinase kinase kinase (MEKK1) in a tetracycline-regulated expression system, we found that expression of DA-MEKK1 results in the apoptosis of Jurkat cells in parallel with prolonged JNK activation. Moreover, DA-MEKK1 induced Fas ligand (FasL) cell surface and mRNA expression, as well as FasL promoter activation. Interference with Fas/FasL interaction prevented DA-MEKK1-mediated apoptosis. In comparing the effect of different stress stimuli to DA-MEKK1, we found that UV, gamma irradiation, and anisomycin prolonged JNK activation in parallel with FasL expression and onset of cell death. In addition, these stimuli also enhance cell surface expression of FasL. Interference with Fas/FasL interactions inhibited anisomycin but not UV- or gamma irradiation-induced apoptosis. Our data show that while the JNK pathway contributes to stress-induced apoptosis in T lymphocytes by regulating FasL expression, not all stress stimuli use the same cell death pathway.

[Dimensions of leadership practice by nursing service managers]

Leadership development is an important component of the nursing service manager's personal and professional development. Competent leadership is required to lead the nursing service in the right direction within the context of dynamic political and social changes. Various internal and external environmental variables have a significant influence on leadership behaviour and practice. The purpose with this study is to explore and describe the characteristics or dimensions of leadership excellence by the nursing service manager. An exploratory and descriptive research design was followed and data collection was done by means of focus group interviews. The results do not show a significant difference between the knowledge already generated by research, or described in the literature, but is utilised as the basis of leadership development of nursing service managers. A leadership development programme for nursing service managers, based on the results of this study, is recommended.

Dimensies van leierskapsbeoefening deur verpleegdiensbestuurders

Leadership development is an important component of the nursing service manager’s personal and professional development. Competent leadership is required to lead the nursing service in the right direction within the context of dynamic political and social changes. Various internal and external environmental variables have a significant influence on leadership behaviour and practice. The purpose with this study is to explore and describe the characteristics or dimensions of leadership excellence by the nursing service manager. An exporatory and descriptive research design was followed and data collection was done by means of focus group interviews. The results do not show a significant difference between the knowledge already generated by research, or described in the literature, but is utilised as the basis of leadership development of nursing service managers. A leadership development programme for nursing service managers, based on the results of this study, is recommended.

Interleukin 4 activates a signal transducer and activator of transcription (Stat) protein which interacts with an interferon-gamma activation site-like sequence upstream of the I epsilon exon in a human B cell line. Evidence for the involvement of Janus kinase 3 and interleukin-4 Stat

Germ line C transcripts can be induced by IL-4 in the human B cell line, BL-2. Utilizing a IFN-gamma activation site-like DNA sequence element located upstream of the I epsilon exon, we demonstrated by gel mobility shift assays that IL-4 induced a binding activity in the cytosol and nucleus of BL-2 cells. This factor was designated IL-4 NAF (IL-4-induced nuclear-activating factors) and was identified as a tyrosine phosphoprotein, which translocates from the cytosol to the nucleus upon IL-4 treatment. Because these are the characteristics of a signal transducer and activator of transcription (Stat) protein, we determined whether antibodies to Stat proteins will interfere with gel mobility shift and found that antibodies to IL-4 Stat, also known as Stat6, but not antibodies to other Stat proteins, interfere with the formation of the IL-4 NAF complex. Congruous with the involvement of a Stat protein, IL-4 induced robust Janus kinase 3 (JAK3) activity in BL-2 cells. Cotransfection of JAK3 with IL-4 Stat into COS-7 cells produced an intracellular activity which bound the same IFN-gamma activation site-like sequence and comigrated with IL-4 NAF in electrophoretic mobility shift assay. These results show that IL-4 NAF is IL-4 Stat, which is activated by JAK3 in response to IL-4 receptor engagement.

The membrane immunoglobulin receptor utilizes a Shc/Grb2/hSOS complex for activation of the mitogen-activated protein kinase cascade in a B-cell line

Ligation of membrane immunoglobulin M (mIgM) receptor in the Ramos B-cell line induced tyrosine phosphorylation of several intracellular substrates, including the adaptor protein. Shc. Phosphorylated Shc could be seen to associate with Grb2 in a complex which included hSOS. Inasmuch as hSOS is involved in p21ras activation, we also demonstrated that mIgM ligation activated a Ras-dependent kinase cascade in which sequential activation of Raf-1 and MEK-1 culminates in the activation of p42 mitogen-activated protein (MAP) kinase (ERK-2). The tumour promoter and protein kinase C agonist, phorbol 12-myristate 13-acetate (PMA), also activated Raf-1, MEK-1, and MAP kinase in Ramos cells, but did not induce tyrosine phosphorylation of Shc or Shc/Grb2 association. Okadaic acid, another tumour promoter and serine/threonine phosphatase inhibitor, activated p42 MAP kinase without activating Raf-1 or MEK-1, suggesting the existence of a serine/threonine phosphatase which directly regulates MAP kinase activity.

Definition of a lamina propria T cell responsive state. Enhanced cytokine responsiveness of T cells stimulated through the CD2 pathway

This study was designed to compare cytokine release in lamina propria lymphocytes (LPLs) and PBLs activated by Abs against CD3, CD2, and CD28. LPL T cells were significantly more responsive to CD2 ligation than PBL, as determined by release of IFN-gamma, IL-2, IL-4, and TNF-alpha. Moreover, CD28 co-ligation in LPLs exaggerated CD2 &gt; CD3 dominance in cytokine induction. PHA-activated PBLs expressed more CD2 receptors than freshly isolated LPLs, but were less responsive to activation through CD2, indicating that postreceptor pathways in LPL may be adapted specifically to facilitate CD2-mediated cytokine secretion. Antiphosphotyrosine (APT) immunoblotting revealed inducible substrate phosphorylation during CD2, but not CD3, ligation in whole LPLs, as well as LPL-derived T cell lines. PBLs cocultured with an irradiated B cell line, Daudi, and IL-2 for 5 days attained a CD2-dominant cytokine-secretion pattern with identical tyrosine phosphorylation profiles as freshly isolated LPL or LPL T cell lines. PHA-activated PBLs did not produce these tyrosine phosphorylation profiles. This suggests that B lymphocytes in the lamina propria may contribute to a T cell differentiation process in which CD2, possibly by potentiation of its postreceptor pathway, becomes a prominent receptor for induction of cytokine secretion.

Definition of a lamina propria T cell responsive state. Enhanced cytokine responsiveness of T cells stimulated through the CD2 pathway

This study was designed to compare cytokine release in lamina propria lymphocytes (LPLs) and PBLs activated by Abs against CD3, CD2, and CD28. LPL T cells were significantly more responsive to CD2 ligation than PBL, as determined by release of IFN-gamma, IL-2, IL-4, and TNF-alpha. Moreover, CD28 co-ligation in LPLs exaggerated CD2 > CD3 dominance in cytokine induction. PHA-activated PBLs expressed more CD2 receptors than freshly isolated LPLs, but were less responsive to activation through CD2, indicating that postreceptor pathways in LPL may be adapted specifically to facilitate CD2-mediated cytokine secretion. Antiphosphotyrosine (APT) immunoblotting revealed inducible substrate phosphorylation during CD2, but not CD3, ligation in whole LPLs, as well as LPL-derived T cell lines. PBLs cocultured with an irradiated B cell line, Daudi, and IL-2 for 5 days attained a CD2-dominant cytokine-secretion pattern with identical tyrosine phosphorylation profiles as freshly isolated LPL or LPL T cell lines. PHA-activated PBLs did not produce these tyrosine phosphorylation profiles. This suggests that B lymphocytes in the lamina propria may contribute to a T cell differentiation process in which CD2, possibly by potentiation of its postreceptor pathway, becomes a prominent receptor for induction of cytokine secretion.

The T-cell antigen receptor utilizes Lck, Raf-1, and MEK-1 for activating mitogen-activated protein kinase. Evidence for the existence of a second protein kinase C-dependent pathway in an Lck-negative Jurkat cell mutant

T-cell antigen receptor (TCR) ligation of an Lck-deficient Jurkat mutant, J.CaM1, with anti-CD3 or anti-TCR beta monoclonal antibodies failed to induce tyrosine phosphorylation and activation of p42MAPK. The same stimuli activated mitogen-activated protein (MAP) kinase in J.CaM1 cells transfected with Lck, demonstrating that Lck plays a critical role in MAP kinase activation. Utilizing immunocomplex kinase assays, we demonstrated that TCR/CD3 ligation activated a MAP kinase kinase kinase (Raf-1) as well as a MAP kinase kinase (MEK-1) in Jurkat but not in J.CaM1 cells. It was possible, however, to activate Raf-1, MEK-1, and p42MAPK in J.CaM1 cells during treatment with the phorbol ester phorbol 12-myristate 13-acetate, which activates protein kinase C (PKC). This demonstrates the presence of a PKC-dependent pathway which functions independently from Lck in MAP kinase activation. Stimulation of Jurkat cells with either anti-TCR beta or anti-CD3 monoclonal antibody failed to induce substantial tyrosine phosphorylation of Shc proteins or their association with Grb2 which forms a complex with the guanine nucleotide exchange factor hSOS. However, the same stimuli induced tyrosine phosphorylation of another putative guanine nucleotide exchange factor, p95Vav, in Jurkat but not J.CaM1 cells. Moreover, Lck was reversibly co-immunoprecipitated with p95Vav, and the stoichiometry of binding increased in anti-CD3-treated Jurkat cells. Phorbol 12-myristate 13-acetate did not induce tyrosine phosphorylation of p95Vav. These data show that the TCR activates MAP kinase by way of a signaling cascade, which depends upon Lck, and may be mediated by downstream events involving PKC or p95Vav which act on Raf-1 and MEK-1.

Intestinal intraepithelial lymphocytes are activated and cytolytic but do not proliferate as well as other T cells in response to mitogenic signals

Compared with T lymphocytes from other organs, intestinal intraepithelial lymphocytes (IEL) proliferate weakly in response to CD3/TCR ligation, and they do not respond at all to treatment with other mitogenic stimuli. These signals also failed to induce expression of the IL-2R alpha-chain on the surface of most IEL. IEL from germ-free mice, from V gamma 1.1-transgenic mice, and from beta 2-microglobulin-deficient mice also gave a weak proliferative response. Therefore, the low proliferative response is not linked to the level of exposure to gut bacterial flora, the V gamma region expressed by the TCR-gamma delta + IEL, or the presence of class I molecules that may be recognized by CD8+ IEL. The relatively small amount of proliferation in response to TCR signaling, therefore, is not likely to be the result of induction of anergy caused by previous contact with Ag. In contrast, ligation of the CD3/TCR complex could elicit a rapid cytotoxic response and serine esterase release by IEL. The unusual functional capabilities and the activation state of IEL are independent of the TCR isotype expressed by these cells. Freshly isolated IEL have a high intracellular microtubule-associated protein kinase-2 (MAP-2K) activity level, further suggesting that these cells are activated despite their weak proliferative response. Consistent with this, MAP-2K is tyrosine-phosphorylated in both untreated and PMA-treated IEL. In contrast, MAP-2K activation and tyrosine phosphorylation occur in other T cells only when they are activated by PMA or other treatments. MAP-2K activity also is elevated in IEL from germ-free mice, demonstrating that activation does not depend on normal levels of exposure to bacterial flora. The activation of protein kinases such as MAP-2K could reflect the differentiation state of IEL or Ag receptor stimulation of some of these cells by epithelial cells in the preparation.

Intestinal intraepithelial lymphocytes are activated and cytolytic but do not proliferate as well as other T cells in response to mitogenic signals

Compared with T lymphocytes from other organs, intestinal intraepithelial lymphocytes (IEL) proliferate weakly in response to CD3/TCR ligation, and they do not respond at all to treatment with other mitogenic stimuli. These signals also failed to induce expression of the IL-2R alpha-chain on the surface of most IEL. IEL from germ-free mice, from V gamma 1.1-transgenic mice, and from beta 2-microglobulin-deficient mice also gave a weak proliferative response. Therefore, the low proliferative response is not linked to the level of exposure to gut bacterial flora, the V gamma region expressed by the TCR-gamma delta + IEL, or the presence of class I molecules that may be recognized by CD8+ IEL. The relatively small amount of proliferation in response to TCR signaling, therefore, is not likely to be the result of induction of anergy caused by previous contact with Ag. In contrast, ligation of the CD3/TCR complex could elicit a rapid cytotoxic response and serine esterase release by IEL. The unusual functional capabilities and the activation state of IEL are independent of the TCR isotype expressed by these cells. Freshly isolated IEL have a high intracellular microtubule-associated protein kinase-2 (MAP-2K) activity level, further suggesting that these cells are activated despite their weak proliferative response. Consistent with this, MAP-2K is tyrosine-phosphorylated in both untreated and PMA-treated IEL. In contrast, MAP-2K activation and tyrosine phosphorylation occur in other T cells only when they are activated by PMA or other treatments. MAP-2K activity also is elevated in IEL from germ-free mice, demonstrating that activation does not depend on normal levels of exposure to bacterial flora. The activation of protein kinases such as MAP-2K could reflect the differentiation state of IEL or Ag receptor stimulation of some of these cells by epithelial cells in the preparation.

Nerve growth factor stimulates the tyrosine phosphorylation of MAP2 kinase in PC12 cells

NGF treatment of PC12 cells results in the rapid activation of MAP2 kinase. We report here that the induction of enzyme activity was correlated with the phosphorylation of MAP2 kinase, detected by metabolic labeling of the enzyme and with anti-phosphotyrosine antibodies. NGF stimulated the phosphorylation of MAP2 kinase on tyrosine, as well as serine and threonine residues. Western blot analysis using a polyclonal anti-phosphotyrosine antibody demonstrated that the tyrosine phosphorylation of MAP2 kinase was maximal within 2 min following NGF exposure and preceded the induction of MAP2 kinase activity. The NGF-stimulated tyrosine phosphorylation of an identified substrate provides direct evidence for the participation of a tyrosine kinase in the mechanism of action of NGF.

HIV inhibits the early steps of lymphocyte activation, including initiation of inositol phospholipid metabolism

Mechanisms accounting for HIV-associated suppression of lymphocyte proliferation were investigated. In previous work we demonstrated that purified and inactivated HIV-suppressed lymphoid cell proliferation. In this report we used an inactivated preparation of HIV obtained from infected CEM cells grown in serum free media and demonstrated that this HIV-associated suppression acted in the early steps of activation to inhibit the incorporation of radiolabeled phosphorus into phosphatidylinositol 4,5-bisphosphate and phosphatidic acid. Initially we showed that both purified CD4 and CD8 T lymphocyte subsets were affected and HIV-associated inhibition did not require the CD4 molecule. Impaired lymphocyte blastogenesis (decreased size and granularity and decreased expression of receptors to IL-2 and transferrin) in response to PHA indicated an effect of inactivated HIV on the early steps of activation. This was confirmed by time studies where 1) a 2 min HIV-pretreatment followed by washing before stimulation was sufficient to inhibit PHA induced proliferation of normal lymphocytes, and 2) addition of HIV to PHA prestimulated lymphocytes failed to inhibit proliferation, e.g., there was no effect on preactivated lymphocytes. HIV was mainly inhibitory of lymphocyte proliferation induced by PHA or mAb to the CD3 receptor. In contrast to the effect on the CD3/TiR, responses via the CD2 receptor were not suppressed, e.g., stimulation with the monoclonal antibodies T11(2) + T11(3). Inasmuch as responses by direct A23187 + PMA stimulation of intracellular pathways were also inhibited, it appears that the HIV-induced defect was not (or not only) membrane receptor mediated. The earliest (min) measurable event after stimulation was the initial increase in intracellular Ca2+ which was unaffected by HIV pretreatment. The next measurable event (min to h) of stimulation is a sustained increase in inositol phospholipid turnover. Pretreatment of mononuclear cells with inactivated HIV resulted in a decreased inositol phospholipid turnover as judged from decreased 32P incorporation into phosphatidylinositol 4-phosphate and phosphatidylinositol 4,5-bisphosphate. This led to decreased generation of DAG as reflected in the reduced radiolabeling of its metabolite PA. Reduced availability of DAG presumably interferes with pkC activation and leads to decreased expression of receptors for IL-2 and transferrin and impaired proliferation.

HIV inhibits the early steps of lymphocyte activation, including initiation of inositol phospholipid metabolism

Mechanisms accounting for HIV-associated suppression of lymphocyte proliferation were investigated. In previous work we demonstrated that purified and inactivated HIV-suppressed lymphoid cell proliferation. In this report we used an inactivated preparation of HIV obtained from infected CEM cells grown in serum free media and demonstrated that this HIV-associated suppression acted in the early steps of activation to inhibit the incorporation of radiolabeled phosphorus into phosphatidylinositol 4,5-bisphosphate and phosphatidic acid. Initially we showed that both purified CD4 and CD8 T lymphocyte subsets were affected and HIV-associated inhibition did not require the CD4 molecule. Impaired lymphocyte blastogenesis (decreased size and granularity and decreased expression of receptors to IL-2 and transferrin) in response to PHA indicated an effect of inactivated HIV on the early steps of activation. This was confirmed by time studies where 1) a 2 min HIV-pretreatment followed by washing before stimulation was sufficient to inhibit PHA induced proliferation of normal lymphocytes, and 2) addition of HIV to PHA prestimulated lymphocytes failed to inhibit proliferation, e.g., there was no effect on preactivated lymphocytes. HIV was mainly inhibitory of lymphocyte proliferation induced by PHA or mAb to the CD3 receptor. In contrast to the effect on the CD3/TiR, responses via the CD2 receptor were not suppressed, e.g., stimulation with the monoclonal antibodies T11(2) + T11(3). Inasmuch as responses by direct A23187 + PMA stimulation of intracellular pathways were also inhibited, it appears that the HIV-induced defect was not (or not only) membrane receptor mediated. The earliest (min) measurable event after stimulation was the initial increase in intracellular Ca2+ which was unaffected by HIV pretreatment. The next measurable event (min to h) of stimulation is a sustained increase in inositol phospholipid turnover. Pretreatment of mononuclear cells with inactivated HIV resulted in a decreased inositol phospholipid turnover as judged from decreased 32P incorporation into phosphatidylinositol 4-phosphate and phosphatidylinositol 4,5-bisphosphate. This led to decreased generation of DAG as reflected in the reduced radiolabeling of its metabolite PA. Reduced availability of DAG presumably interferes with pkC activation and leads to decreased expression of receptors for IL-2 and transferrin and impaired proliferation.

Complexing of the CD-3 subunit by a monoclonal antibody activates a microtubule-associated protein 2 (MAP-2) serine kinase in Jurkat cells

Treatment of Jurkat T-cells with anti-CD-3 monoclonal antibodies resulted in the rapid and transient activation of a serine kinase which utilized the microtubule-associated protein, MAP-2, as a substrate in vitro. The kinase was also activated on treatment of Jurkat cells with phytohaemagglutinin, but with a different time course. The activation of the MAP-2 kinase by anti-CD-3 antibodies was dose-dependent, with maximal activity observed at concentrations of greater than 500 ng/ml. Normal human E-rosette-positive T-cells also exhibited induction of MAP-2 kinase activity during anti-CD-3 treatment. The enzyme was optimally active in the presence of 2 mM-Mn2+; lower levels of activity were observed with Mg2+, even at concentrations up to 20 mM. The kinase was partially purified by passage over DE-52 Sephacel with the activity eluting as a single peak at 0.25 M-NaCl. The molecular mass was estimated to be 45 kDa by gel filtration. The activation of the MAP-2 kinase was probably due to phosphorylation of this enzyme as treatment with alkaline phosphatase diminished its activity. These data demonstrate that the stimulation of T-cells through the CD-3 complex results in the activation of a novel serine kinase which may be critically involved in signal transduction in these cells.

Inhibitory effect of an antibody against alpha 1-acid glycoprotein (alpha 1-AGP) on autologous mixed lymphocyte reaction and anti-T3 T-lymphocyte activation

The action of an anti-alpha 1-AGP antibody on AMLR, anti-T3 and PHA T-lymphocyte proliferative response was evaluated. We observed a strong dose-dependent inhibition on T-lymphocyte proliferative responsiveness to autologous non-T cells and to anti-T3 stimulus, whereas PHA activation was unaffected. A lower degree of inhibition of the proliferative response was also observed on pretreating both T and non-T cells with the antibody; the addition of anti-alpha 1-AGP in the culture containing cells pretreated with the antibody showed a further inhibition of thymidine incorporation. The data suggest a direct influence of the antibody on membrane alpha 1-AGP and support a positive role of this glycoprotein (distinct from Ia and T3 antigens) on both anti-T3 and autologous non-T cell T-lymphocyte responsiveness, thus indicating the involvement of alpha 1-AGP in the T3-Ti antigen-specific pathway of T-cell activation.