The six-day-old rat air pouch model of inflammation: characterization of the inflammatory response to carrageenan

Inflammation was induced in the 6-day-old rat air pouch by injection of carrageenan. The model was characterized in terms of exudate volume, leucocyte influx, cell free protein, prostaglandin E2 levels, and granuloma formation. The time course of all these inflammatory markers, except prostaglandin E2, showed a 3-hr lag followed by a rapid increase to 8 hr. Thereafter, the rate of increase was much slower to 48 hr. Differential cell counts indicated a predominantly polymorphonuclear cell response (75%) during the first 48 hr. Prostaglandin E2 levels increased rapidly after a 3-hr lag, to a maximum of 440 +/- 140 ng/mL at 15 hr and thereafter quickly declined to 140 +/- 60 ng/mL at 21 hr. Prostaglandin E2 levels were the most sensitive inflammatory marker to (S+)-ibuprofen and were reduced dose dependently in the range 0.05 to 1 mg/kg. We have demonstrated the time course for duration of NSAID-induced reduction of prostaglandin E2 levels during inflammation in an individual animal. Rac-ibuprofen (0.1-1 mg/kg) reduced leucocyte influx at 3 and 5 hr, after which drug effects gradually diminished by 24 hr. Rac-ibuprofen at 1 mg/kg significantly reduced the volume of air pouch exudate recovered at 24 hr but had no effect on protein levels.

Characterization of mutated transforming growth factor-beta s which possess unique biological properties

Transforming growth factor-beta (TGF-beta) is a potent regulator of cell growth and differentiation. On the basis of the crystal structure of TGF-beta 2, we have designed and synthesized two mutant TGF-beta s, TGF-beta 1 (71 Trp) and TGF-beta 1 (delta 69-73). Although both of these molecules inhibited the growth of Mv1Lu mink lung epithelial cells and LS1034 colorectal cancer cells, which are affected equally by TGF-beta 1 and TGF-beta 2, TGF-beta 1 (delta 69-73) was much less potent than TGF-beta 1 or TGF-beta 1 (71 Trp) at inhibiting the growth of LS513 colorectal cancer cells which are growth-inhibited by TGF-beta 1 but not TGF-beta 2. Both TGF-beta 1 (71 Trp) and TGF-beta 1 (delta 69-73) increased levels of mRNAs for fibronectin and plasminogen activator inhibitor with Mv1Lu cells, whereas only TGF-beta 1 (71 Trp) and not TGF-beta 1 (delta 69-73) up-regulated the mRNA level of carcinoembryonic antigen in LS513 cells. The expression level of carcinoembryonic antigen mRNA in LS1034 cells was not altered by either wild-type or mutant TGF-beta s. Receptor labeling experiments demonstrated that TGF-beta 1 (71 Trp) bound with high affinity to the cell-surface receptors of Mv1Lu, LS1034, and LS513 cells while TGF-beta 1 (delta 69-73) bound effectively to the receptors of Mv1Lu and LS1034 cells but much less to the receptors on LS513 cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of neonatal capsaicin on peptide-containing primary afferent fibres, eosinophil distribution and hyperresponsiveness in rat lung tissue following experimentally induced eosinophilia

Treatment of neonatal rats with capsaicin causes a 92.4% loss of calcitonin-gene-related-peptide-immunoreactive unmyelinated sensory afferent fibres in the airways epithelium, vascular smooth muscle and perivascular adventitial layer of lung tissue compared with vehicle-treated controls. Rats were administered Sephadex particles i.v. 8-10 weeks after either capsaicin or vehicle treatment at birth in order to induce a granulomatous tissue inflammation, peripheral blood eosinophilia and pulmonary eosinophil invasion [Laycock et al., Int Arch Allergy Appl Immunol 1986;81:363-367]. The animals also exhibited lung hyperreactivity in vitro in response to carbachol and serotonin (5HT). In Sephadex-treated rats, capsaicin pretreatment did not affect the number of inflammatory cells in peripheral blood, the number of eosinophils in lung tissue, or the distribution of eosinophils in the adventitial tissue of blood vessels. Potencies of concentration-related contractures of lung tissue to 5HT and carbachol were increased by 50- to 100-fold in Sephadex-treated animals compared to controls, but in neither group was potency influenced by capsaicin pretreatment at birth. Recruitment and subsequent regional distribution of inflammatory cells in lung tissue and the increase in lung hyperresponsiveness exhibited in this model of asthma do not appear to involve neuropeptides released from primary afferent neurones.

Isolated follicular lymphoma cells are resistant to apoptosis and can be grown in vitro in the CD40/stromal cell system

Low-grade follicular non-Hodgkin's lymphomas are characterized by the presence of a t(14;18) chromosomal translocation that results in deregulation of the B-cell lymphoma (Bcl-2) gene. Studies in cell lines and transgenic animal models have suggested that this results in the suppression of apoptotic cell death in germinal centers. B lymphocytes from normal germinal centers and lymph nodes infiltrated by follicular lymphoma were isolated by immunomagnetic depletion of cells bearing CD4, CD8, or slgD for study in vitro. Follicular lymphoma cells expressing Bcl-2 protein were shown to resist apoptosis after isolation, and could be induced to proliferate in a culture system previously described for the growth of normal B lymphocytes. By the use of a mouse fibroblast monolayer transfected with the CDw32 Fc receptor to present CD40 monoclonal antibody in the presence of interleukin-4, prolonged culture was possible. Karyotypic analysis of cultured lymphoma cells showed the t(14;18) translocation, with clonal identity confirmed by polymerase chain reaction amplification of the breakpoints and direct sequence analysis. These findings support the hypothesis that resistance to apoptosis is an influence on the initiation of follicular lymphoma, and provide a novel means of studying in vitro the intercellular reactions that may be important in progression of the disease.

Cluster suicide in rural western Canada

This paper focuses on a series of adolescent suicides which occurred in a small rural community in Western Canada between December 1989 and June 1990. Risk factors for adolescent suicide and recent epidemiological data on cluster suicide are reviewed and discussed. The circumstances of the five adolescent suicides are then discussed, and the question of whether or not this was a cluster suicide is considered. This article supports the view that suicide is an abnormal response to stress or loss and emphasizes the role of genetic psychophysiological predisposition.

Column agglutination technology: the antiglobulin test

A new system for typing and screening blood, based on the sieving effect of glass bead microparticles, has been developed. The test is performed in a microcolumn in which the red cell agglutinates are trapped in the glass bead matrix during centrifugation, and unagglutinated cells form a pellet at the bottom of the column. Anti-human globulin reagents were incorporated in the diluent and the new test system, column agglutination technology, was compared to conventional tube tests and low-ionic-strength method. Sera and plasmas (228 samples) were screened for red cell antibodies with two anti-human globulin reagents: one containing only anti-IgG and the other containing both anti-IgG and anti-C3b, -C3d. After initial testing, there was 94-percent agreement between column agglutination technology and tube tests, and after repeat testing, there was 97-percent agreement. The column agglutination technology anti-human globulin test eliminates the need to wash red cells, which decreases the overall test time. The test is easy to perform, and the results are more objective than those with tube and microplate methods.

Mutant human cells defective in induction of major histocompatibility complex class II genes by interferon gamma

Using immunoselection, we have isolated 11 independent mutant HT1080 fibrosarcoma cell lines defective in the induction by interferon gamma (IFN-gamma) of the expression of the human leukocyte antigen HLA-DRA. The mutations are recessive and fall into five complementation groups. All the mutants are affected mainly in the expression of major histocompatibility complex class II and invariant-chain genes. Type I mutants (three complementation groups) are completely defective in induction of the invariant-chain and class II HLA-DP, -DQ, -DR, and -DM genes, whereas type II mutants (two complementation groups) induce these genes weakly in response to IFN-gamma, in the order DPB > DRA > invariant chain. The induction by IFN-gamma of the mRNAs for class I, TAP1, LMP7, and 9-27 is partially defective and the induction of the proteins IRF-1 and ICAM-1 is normal in both types of mutants. All the mutants respond normally to IFN-alpha. The mutants are stable and thus can be used to clone the affected genes by reversion.

Segregation of delta F508 and normal CFTR alleles in human sperm

Single sperm typing provides an accurate method to order tightly linked loci by single cell DNA high resolution segregation analysis. We have used similar methods to type individual sperm from a known delta F508 cystic fibrosis heterozygote to determine the frequency of the mutation within his germ cell population, and to test possible explanations for the reported sex ratio distortion of the cystic fibrosis (CF) mutation to male offspring. Using a nested polymerase chain reaction we have been able to amplify a single locus sequence, cystic fibrosis transmembrane conductance regulator (CFTR), from a single target sperm haploid genome to detectable amounts without the use of radioactivity. The same sperm from a single male delta F508 carrier were simultaneously typed for the presence of the sex chromosomes to verify the ratio of X- to Y-bearing sperm and to determine the association, if any, between sex and delta F508 in male gametes. We have demonstrated that there is a significant difference in the proportions of 'normal' and 'delta F508' sperm (X2 = 7.36, p < 0.01), although when the same sperm are sexed the difference between delta F508/X and delta F508/Y sperm is not significant (X2 = 1.71, p = 0.192). Single sperm typing can address questions about segregation distortion in man, and it is unlikely that sex ratio distortion for CF carriers is due to events which occur pre-fertilisation. As these data are from one individual only, they should be confirmed for other male carriers, including those with different CF mutations.

Pharmacokinetics of [14C]FCE 22891, a penem antibiotic, following oral administration to healthy volunteers

FCE 22891 is a prodrug of the penem antibiotic FCE 22101 and is suitable for oral administration. The pharmacokinetics of FCE 22891 were investigated in four healthy male volunteers following the oral administration of 500 mg of [14C]FCE 22891. Levels of radioactivity in plasma were always higher and persisted for longer than those of FCE 22101. The time to the maximum concentration of radioactivity in plasma generally coincided with that of FCE 22101. The respective values for the maximum concentrations of radioactivity in plasma were, on average, 8.57 +/- 2.95 micrograms equivalent/ml and 2.97 +/- 2.05 micrograms/ml. Over a 5-day period, mean urinary and fecal recovery of radioactivity accounted for 53.2 and 41.0% of the dose, respectively. The average amount of FCE 22101 excreted in urine and feces corresponded to 9.0 and 1.6% of the dose, respectively. The urinary recovery of the open-ring metabolite P1 and of its 5-S epimer P2 accounted for about 6.5 and 1.2% of the dose, respectively. Other chromatographic peaks corresponding to nonidentified compounds accounted for about 14.0% (polar metabolite fraction; peak P), 3.7% (less polar fraction; peak X), and 15.4% (least polar fraction) of the dose. Elimination of radioactivity and FCE 22101 in urine was rapid. Intersubject variability in the kinetics of total radioactivity in plasma was far less than that observed for FCE 22101. The results of the present study support suggestions that presystemic metabolism of FCE 22101 and/or transformation of the prodrug to compounds other than FCE 22101 are the main cause of intersubject variability in the kinetics of FCE 22101 produced in plasma following oral administration of its prodrug.

Scrapie in the central nervous system: neuroanatomical spread of infection and Sinc control of pathogenesis

Following bilateral intraocular (i.o.) infection of Sinc s7 mice with ME7 scrapie, sequential tissue pools were taken from retina, optic nerve, superior colliculus (SC), dorsal lateral geniculate nucleus (dLGN), visual cortex and cerebellum. The infectivity levels in these pools were estimated by intracerebral (i.c.) assay in C57BL/FaBtDk mice. Infectivity was first detected in retina at 35 days post-injection (as an increase above residual injected inoculum), SC at 56 days, dLGN at 77 days and in optic nerve, visual cortex and cerebellum at 98 days. Pathological lesions were shown to develop in the same sequence later in the incubation period. Comparison of sequential retina and SC assays in congenic mice, which differ only in the vicinity of the Sinc locus, revealed a difference in the initial detection and progression of i.o. infection of between 60 and 100 days, indicating that Sinc acts by delaying the initiation of replication. Higher levels of infectivity were found in retina and SC of mice infected with 79A scrapie, which destroys the photoreceptor layer in the retina, than with ME7 scrapie, which does not. Retrograde transport of infection was indicated by the levels of infectivity in the retina after i.c. infection with ME7 or 79A scrapie. These results indicate that scrapie spread within the central nervous system is restricted to neuroanatomical pathways, and that Sinc controls the initiation, but not the rate of replication.

Eosinophil chemotactic peptide sequences in rat alpha-CGRP. Activation of a novel trophic action by neutral endopeptidase 24.11

Rat alpha- and alpha-CGRP are substrates for endopeptidase 24.11 in vitro. Cleavage of both peptides occurs at several points, including an unusual substrate recognition site to the amino side of ala36. In alpha-CGRP this resulted in the early formation of val32-gly-ser-glu35, a sequence previously reported to be a component of the eosinophil chemotactic factor of anaphylaxis (ECF-A). The biological activity of this peptide fragment was confirmed by bioassay. Chemotactic activity in other hydrolysis fragments of both alpha- and beta-CGRP was observed. Both alpha- and beta-CGRP could thus serve as precursors to different eosinophil chemotactic peptide fragments. A novel function of endopeptidase 24.11 may be to modify rather than to terminate the biological activity of CGRP peptides.

Endopeptidase-24.11 cleaves a chemotactic factor from alpha-calcitonin gene-related peptide

The sequence of rat alpha-calcitonin gene-related peptide (CGRP-alpha) contains the tetrapeptide eosinophil granulocyte chemotactic factor Val32-Gly-Ser-Glu35. Peptide fragments formed following hydrolysis of rat CGRP-alpha in vitro by endopeptidase-24.11 were identified. The tetrapeptide fragment was generated following cleavage at a substrate recognition site unusual for this enzyme (-Glu-Ala-). Chemotactic activity of rat CGRP-alpha was increased following hydrolysis. Furthermore, rat CGRP-beta, which lacks the tetrapeptide sequence and is completely devoid of chemotactic activity, displayed low but measurable activity after hydrolysis. Val-Gly-Ser-Glu was identified as the principle fragment with chemotactic activity in rat CGRP-alpha. The results show that the chemotactic activity of the neuropeptide rat CGRP-alpha towards eosinophil polymorphonuclear leukocytes is increased following its hydrolysis in vitro by endopeptidase 24.11 through the formation of a previously identified eosinophil chemotactic tetrapeptide.

Complications following fast neutron therapy for head and neck cancer

Serious complications resulting from the use of fast neutrons to treat head and neck malignancies are reported in 38 patients. The average interval between treatment and onset of complications was 5.5 years. Significant airways obstruction, requiring a tracheostomy, occurred in two patients, and a gastrostomy or pharyngostomy was performed for intractable dysphagia in six. Eight patients developed osteoradionecrosis: carotid artery rupture occurred in three patients following surgery for residual or recurrent disease. Our experience suggests that complications following fast neutron therapy for head and neck tumours are more severe, more common and occur after a longer time interval than those seen following conventional radiotherapy. Subsequent surgery in the irradiated area is compromised by severely impaired wound healing. When radical surgery is necessary for residual or recurrent disease the entire volume of irradiated tissue must be removed if healing is to be achieved.

Investigations into the mechanism by which sulfated polysaccharides inhibit HIV infection in vitro

Sulfated polysaccharides have been shown to inhibit human immunodeficiency virus (HIV) infection in vitro. Dextrin sulfate, fucoidan, and dextran sulfate fail to neutralize virions directly, but interact with target cells to inhibit virus entry. Ionic interactions of sulfated polyanions with oppositely charged cell surface components, including CD4, have been assumed to be the inhibitory mechanism. It is shown that the sulfated polysaccharides inhibit infection of both CD4+ and CD4- cell lines by HIV and also that they inhibit HTLV-1 and, to a lesser extent, the simian retrovirus, MPMV, which use receptors other than CD4. One binding site for radiolabeled fucoidan on the surface of human T cells is an 18 kD protein, but its significance is not yet clear.