Eosinophil-activating factor (EAF) production by a human cell line (ESH 98) stimulated with tumour necrosis factor.

A new cell line has been produced by fusing human cervical keratinocytes with HeLa cells. This cell line secretes eosinophil-activating activity upon stimulation with tumour necrosis factor (TNF). About one-third of the eosinophil-activating activity co-purifies with eosinophil-activating factor (EAF) from mononuclear cell supernatants. The purification procedure indicates that it resembles EAF in molecular weight and acidity. It also resembles EAF in its effect on eosinophils. Not only does it enhance the cytotoxic activity of eosinophils to antibody-coated schistosomula of Schistosoma mansoni, but it also increases the oxidative activity of eosinophils, as measured by reduction of nitroblue tetrazolium, and changes the morphology of eosinophils, affecting the distribution of F-actin in the cell.     

Viral serpin, Serp-1, inhibits endogenous angiogenesis in the chicken chorioallantoic membrane model.

BACKGROUND: Angiogenesis is a critical factor in the development of malignant tumors, in arthritic joints, and in cardiovascular disease. In cardiovascular disease, angiogenesis is recognised both as a potential therapy and as a complicating factor in atherosclerotic plaque rupture and thrombotic obstruction. Serine proteases regulate thrombosis, inflammation, and cell invasion, events that trigger various stages of angiogenesis and are in turn regulated by inhibitors, termed serpins. Serp-1 is a secreted anti-inflammatory viral serpin that profoundly inhibits early mononuclear cell invasion, and the development of atherosclerosis, transplant vasculopathy, and arthritis in a range of animal models. METHODS: The capacity of Serp-1 to alter angiogenesis was evaluated in the chicken chorioallantoic membrane (CAM) model using morphometric analysis of vascular changes and RT-PCR to explore alterations in gene expression. RESULTS: Serp-1 inhibited endogenous angiogenesis in a dose-dependent manner, with associated altered expression of laminin and vascular endothelial growth factor (VEGF). Serp-1 was ineffective in CAMs no longer in the rapid growth phase. Similar inhibition of angiogenesis was detected after inhibition of VEGF, but not after treatment with the inactivated reactive center loop mutant of Serp-1. CONCLUSIONS: The angiogenic process can be controlled using Serp-1, an anti-inflammatory agent that is effective at low concentrations with rapid reversibility, targets endothelial cells, and reduces the availability of VEGF. These properties may be especially important in cardiovascular disease, reducing plaque destabilization. It is likely that the anti-angiogenic activity of Serp-1 contributes to the observed anti-inflammatory and anti-atherogenic actions with potential importance in this therapeutic setting.     

Release of lymphotoxin by control and chemical carcinogen-treated lymphocyte cultures derived from black healthy subjects and cancer patients

In an age-adjusted comparison with white men, black men have a significantly higher increase in esophageal and other types of cancer associated with environmental causes. The basis of this increase in cancer rates in blacks over the last two decades is unknown. Since cancer patients generally show an impairment in cell-mediated immune (CMI) functions, we measured certain CMI reactions in cultured lymphocytes derived from black healthy subjects and cancer patients. We also determined the levels of aryl hydrocarbon hydroxylase (AHH) induced in these lymphocytes. AHH catalyzes the activation of polycyclic aromatic hydrocarbons (PAH) to intermediates which might alter CMI functions.     

Mutation spectrum and genotype-phenotype analyses in Cowden disease and Bannayan-Zonana syndrome, two hamartoma syndromes with germline PTEN mutation

The tumour suppressor gene PTEN , which maps to 10q23.3 and encodes a 403 amino acid dual specificity phosphatase (protein tyrosine phosphatase; PTPase), was shown recently to play a broad role in human malignancy. Somatic PTEN deletions and mutations were observed in sporadic breast, brain, prostate and kidney cancer cell lines and in several primary tumours such as endometrial carcinomas, malignant melanoma and thyroid tumours. In addition, PTEN was identified as the susceptibility gene for two hamartoma syndromes: Cowden disease (CD; MIM 158350) and Bannayan-Zonana (BZS) or Ruvalcaba-Riley-Smith syndrome (MIM 153480). Constitutive DNA from 37 CD families and seven BZS families was screened for germline PTEN mutations. PTEN mutations were identified in 30 of 37 (81%) CD families, including missense and nonsense point mutations, deletions, insertions, a deletion/insertion and splice site mutations. These mutations were scattered over the entire length of PTEN , with the exception of the first, fourth and last exons. A 'hot spot' for PTEN mutation in CD was identified in exon 5 that contains the PTPase core motif, with 13 of 30 (43%) CD mutations identified in this exon. Seven of 30 (23%) were within the core motif, the majority (five of seven) of which were missense mutations, possibly pointing to the functional significance of this region. Germline PTEN mutations were identified in four of seven (57%) BZS families studied. Interestingly, none of these mutations was observed in the PTPase core motif. It is also worthy of note that a single nonsense point mutation, R233X, was observed in the germline DNA from two unrelated CD families and one BZS family. Genotype-phenotype studies were not performed on this small group of BZS families. However, genotype-phenotype analysis inthe group of CD families revealed two possible associations worthy of follow-up in independent analyses. The first was an association noted in the group of CD families with breast disease. A correlation was observed between the presence/absence of a PTEN mutation and the type of breast involvement (unaffected versus benign versus malignant). Specifically and more directly, an association was also observed between the presence of a PTEN mutation and malignant breast disease. Secondly, there appeared to be an interdependent association between mutations upstream and within the PTPase core motif, the core motif containing the majority of missense mutations, and the involvement of all major organ systems (central nervous system, thyroid, breast, skin and gastrointestinal tract). However, these observations would need to be confirmed by studying a larger number of CD families.      

Effects of a viral laryngotracheitis on the epithelial barrier of chicken airways

The effects of a virus infection on the barrier function of tracheal epithelium were compared to the effects of a chemical agent (methacholine) which selectively increases membrane permeability, and both were compared to controls. The disruption of the airway epithelium induced by the virus infection caused an increased permeation of horseradish peroxidase (HRP) through this barrier. Methacholine enhanced HRP uptake from the airway lumen to the blood as compared to controls. Visualization of HRP in the tracheal epithelium by transmission electron microscopy correlated with the radioimmunoassay measurements in the blood. Serial anti-HRP antibody titers were measured by a competitive binding technique. The antigen permeation induced by methacholine was associated with an enhanced anti-HRP antibody production. The larger increase in antigen permeation seen with the viral infection was associated with depressed anti-HRP titers. It was concluded that viral disruption of the airway epithelial barrier may contribute to an increased uptake of orally inhaled antigens. The relationship, however, between the increased antigen penetration consequent to the viral infection and the development of allergy remains unclear.     

Organotypic culture of embryonic electromotor system tissues from Torpedo marmorata

An explant culture system has been used to study the electric organ and electric lobe tissues of Torpedo marmorata at different stages during the development of the electromotor system.The myotubes in tissue expiants, taken from the electric organ primordia of 33–38 mm body-length embryos prior to electrocyte differentiation, contract spontaneously on explantation and have electrogenic membranes. The myotubes subsequently lose these properties in vitro and can differentiate in the absence of neural tissue into immature electrocytes which have morphologically characteristic postsynaptic membranes.Isolated expiants of differentiated electric organ tissue from 60–100 mm body-length embryos can be maintained for 3 to 4 weeks in vitro but cellular outgrowth is minimal. In contrast, a rapid, dense outgrowth of cells and a subsequent regeneration of myotubes occurs when differentiated electric organ explants are co-cultured with electric lobe tissue from embryos of the same stage. Cellular outgrowth from differentiated electric-organ tissue expiants can be stimulated by spinal cord, medulla, cerebellum and heart tissues but a subsequent regeneration of myotubes has not been observed. Myotube regeneration in the presence of electric lobe tissue is maximal with tissue from 60–80 mm body-length embryos. The myotubes that regenerate from differentiated electric organ expiants have not been observed to differentiate into electrocytes.Neuritic outgrowth in vitro occurs with electric lobe tissue taken at two different embryonic stages. The first stage corresponds to a period when most of the neuroepithelial cells in the lobe anlagen are withdrawing from the mitotic cycle and projecting axons into the branchial arches. The second, later stage is when the electromotorneurones are normally generating axon collaterals that are invading the interelectrocyte space of electrocyte columns. Maximum neuritic outgrowth at this second, later stage is obtained with tissue from 60–80 mm body-length embryos. Although neuritic invasion of electrocyte column expiants can be obtained in electric organ—electric lobe co-cultures at this later stage, synapses similar to those observed during the early stages of synaptogenesis in the electric organs in vivo have not been observed in vitro.     

Conditioned changes in ultrasonic vocalizations to an aversive olfactory stimulus are lateralized in 6-day-old rats

Using a soft rubber plug to block airflow in one naris, Kucharski, Johanson, and Hall (1986) found that some forms of olfactory memory (e.g., odor preferences) were lateralized in young rats while other forms (e.g., conditioned activation and mouthing) were not. The present experiments extended that research by showing that conditioned increases in ultrasonic vocalizations were also lateralized. That is, when exposed to an odor that was previously paired with footshock, 6-day-old rats significantly increased their rate of vocalizing. This response only occurred, however, when the naris open at training was also open at test. The use of the developing rat as a natural split-brain preparation appears to be an effective procedure with which to broaden current approaches to the analysis of learning, memory, and emotion.     

Effects of depressive symptoms and mental health quality of life on use of highly active antiretroviral therapy among HIV-seropositive women

This study examines the effects of depressive symptoms and mental health quality of life on utilization of highly active antiretroviral therapy (HAART) among HIV-seropositive women. Data were collected biannually from 1996 through 1998 in a prospective cohort study. Women reported use of antiretroviral therapy, health and mental health status, demographics, and social and behavioral factors; CD4 count and viral load also were assessed. Random effects regression models estimated the longitudinal effects of depressive symptoms and mental health quality of life on the probability of HAART utilization, controlling for clinical indicators (CD4 count, viral load, symptom presence), demographics (race, age, education), behavioral factors (drug/alcohol use, clinical trials participation), service features (insurance status, mental health service utilization), and study site. High levels of depressive symptoms and poor mental health quality of life were found, and they significantly reduced the probability of HAART utilization. Receiving mental health services significantly increased the probability of utilizing HAART. HIV-seropositive women characterized as being in poor mental health were less likely to use HAART, whereas those receiving treatment of mental health difficulties were more likely to use HAART. These findings suggest that efforts to enhance women's access to psychological treatment may increase their use of the latest HIV therapies.