Interleukin-6 localisation in the synovial membrane in rheumatoid arthritis

Polyclonal antibodies were raised in rabbits against Interleukin-6 (IL-6) by immunisation with a synthetic peptide of identical sequence to the amino terminal 12 amino acids of human IL-6. These antibodies reacted with recombinant IL-6 by ELISA and stained the cytoplasm of the IL-6 secreting bladder tumour cell line T24. Staining was abolished by prior incubation of the antibody with the IL-6 peptide. F(ab')2 fragments made by pepsin digestion of the IgG were immunopurified, labelled with biotin and retained activity in the biochemical and histological assays. Sections of synovial membrane from patients with rheumatoid arthritis (RA) were stained with these antibodies, using an immunoperoxidase technique, and cells containing IL-6 were domonstrated in the thickened synovial lining layer and also in a perivascular distribution in the deeper synovium. In osteoarthritis there were fewer cells in the lining layer and hence localisation appeared similar in both the interstitial area and lining layer. Double-staining techniques with mouse monoclonal antibodies against cell subset markers in five RA synovial membranes showed that up to 13% of T-cells and 19% of antibody-producing cells stained for IL-6. However, up to 70% of the macrophages contained IL-6 and these were found in close proximity to Ig-producing plasma cells. This study showed that macrophages were the major cells of the immune system in which IL-6 could be localised in RA, and suggests a role for locally produced IL-6 in the stimulation of rheumatoid factor production.

Photosynthetic and photorespiratory characteristics of flaveria species

The genus Flaveria shows evidence of evolution in the mechanism of photosynthesis as its 21 species include C(3), C(3)-C(4), C(4)-like, and C(4) plants. In this study, several physiological and biochemical parameters of photosynthesis and photorespiration were measured in 18 Flaveria species representing all the photosynthetic types. The 10 species classified as C(3)-C(4) intermediates showed an inverse continuum in level of photorespiration and development of the C(4) syndrome. This ranges from F. sonorensis with relatively high apparent photorespiration and lacking C(4) photosynthesis to F. Among the intermediates, the photosynthetic CO(2) compensation points at 30 degrees C and 1150 micromoles quanta per square meter per second varied from 9 to 29 microbars. The values for the three C(4)-like species varied from 3 to 6 microbars, similar to those measured for the C(4) species. The activities of the photorespiratory enzymes glycolate oxidase, hydroxypyruvate reductase, and serine hydroxymethyltransferase decreased progressively from C(3) to C(3)-C(4) to C(4)-like and C(4) species. On the other hand, most intermediates had higher levels of phosphenolpyruvate carboxylase and NADP-malic enzyme than C(3) species, but generally lower activities compared to C(4)-like and C(4) species. The levels of these C(4) enzymes are correlated with the degree of C(4) photosynthesis, based on the initial products of photosynthesis. Another indication of development of the C(4) syndrome in C(3)-C(4)Flaveria species was their intermediate chlorophyll a/b ratios. The chlorophyll a/b ratios of the various Flaveria species are highly correlated with the degree of C(4) photosynthesis suggesting that the photochemical machinery is progressively altered during evolution in order to meet the specific energy requirements for operating the C(4) pathway. In the progression from C(3) to C(4) species in Flaveria, the CO(2) compensation point decreased more rapidly than did the decrease in O(2) inhibition of photosynthesis or the increase in the degree of C(4) photosynthesis. These results suggest that the reduction in photorespiration during evolution occurred initially by refixation of photorespired CO(2) and prior to substantive reduction in O(2) inhibition and development of the C(4) syndrome. However, further reduction in O(2) inhibition in some intermediates and C(4)-like species is considered primarily due to the development of the C(4) syndrome. Thus, the evolution of C(3)-C(4) intermediate photosynthesis likely occurred in response to environmental conditions which limit the intercellular CO(2) concentration first via refixation of photorespired CO(2), followed by development of the C(4) syndrome.

Plant thioredoxin h: an animal-like thioredoxin occurring in multiple cell compartments

Thioredoxin h has been purified to electrophoretic homogeneity from spinach roots using a procedure devised for leaves. The root thioredoxin (h2 form) differed from chloroplast and animal thioredoxins in showing an atypical active site (Cys-Ala-Pro-Cys) but otherwise resembled animal thioredoxin in structure. Sequence data for a total of 72 residues of spinach root thioredoxin h2 (about 69% of the primary structure) showed 43-44% identity with rabbit and rat thioredoxin. Analysis of cell fractions from the endosperm of germinating castor beans revealed that thioredoxin h occurs in the cytosol, endoplasmic reticulum, and mitochondria. The present findings demonstrate a similarity between plant thioredoxin h and animal thioredoxins in structure and intracellular location and raise the question of whether these proteins have similar functions.

Extended nucleotide sequence of the switch region of the murine gene encoding immunoglobulin E

The nucleotide sequence of the switch region (S epsilon) of the gene encoding murine IgE was determined from a germline DNA clone. The sequence extends 1.7 kb 5' to the previously published S epsilon sequence. Another 33 repeat units were located by comparison to the S epsilon consensus sequence. Therefore, the complete S epsilon repetitive sequence consists of 53 repeat units contained in a region about 2.5 kb long.

O-specific side-chain toxin-protein conjugates as parenteral vaccines for the prevention of shigellosis and related diseases

Only indirect evidence has been cited to document that lipopolysaccharide-mediated virulence at the bacterial level and serum antibodies to the O-specific side chain of the lipopolysaccharide molecule may prevent shigellosis. Our proposed use of the B subunit of Shiga toxin as a carrier protein is based upon evidence (even more indirect) that serum antitoxin may reduce the severity of dysentery and diarrhea. Because animal models of disease may provide information inapplicable to the prediction of vaccine-induced protective immunity, we suggest that clinical trials in the population at risk should be started after successful completion of the safety and immunogenicity phases of vaccine development in laboratory animals and in the target population. Clinical studies of shigella vaccines are difficult because of the many causes of dysentery in a population with a high rate of intestinal disease.

Calcium binding protein (calbindin-D28k) and glutamate decarboxylase gene expression after kindling induced seizures

In order to determine whether calcium binding protein (calbindin-D28k or CaBP) and glutamate decarboxylase (GAD) may be involved in the process underlying the generation of seizure activity, changes in CaBP protein and mRNA and in GAD mRNA were examined in the kindling model of epilepsy. Following amygdaloid (AK) and commissure (CK) kindling significant decreases in the concentration of CaBP of 20% and 30%, respectively, were specifically observed in the hippocampal formation. However, using a cDNA specific to mammalian CaBP, Northern analysis of poly(A+) RNA and slot blot analysis of total RNA revealed no changes in the levels of CaBP mRNA in hippocampus, subcortical area (including amygdala, substantia nigra and striatum) or cerebellum of rats sacrificed 30 min, 1 h, 6 h or 24 h after the last kindled seizure. Similarly when these blots were reprobed with a cDNA specific to mammalian GAD, no changes in GAD gene expression were observed. However, fos gene expression was markedly enhanced at 1 h after seizure. We also tested whether changes in CaBP or GAD mRNA could be detected at any of the various stages of the kindling process. Slot blot analysis of cortex, subcortical structures and hippocampus revealed no changes in CaBP or GAD mRNA during the course of commissure kindling. In situ hybridization studies with GAD and CaBP 35S-labeled antisense probes also indicated no obvious changes upon visual analysis of autoradiographs. However, when silver grains were counted, significant changes in GAD mRNA in individual cells in hippocampus and substantia nigra were noted after kindling induced epilepsy. Our results indicate that, unlike fos gene expression, prominent alterations in GAD and CaBP mRNA in gross brain regions (as measured by slot blot and Northern blot analyses) are not observed in the kindling process. However, our in situ hybridization studies suggest that changes in GAD mRNA in individual cells may be involved in the process underlying kindling induced seizure activity.

Evidence for calcium-reducing and excito-protective roles for the calcium-binding protein calbindin-D28k in cultured hippocampal neurons

Neuronal systems for calcium homeostasis are crucial for neuronal development and function and may also contribute to selective neuronal vulnerability in adverse conditions such as exposure to excitatory amino acids or anoxia, and in neurodegenerative diseases. Previous work demonstrated the presence and differential distribution of calcium-binding proteins in the CNS. We now report that a subpopulation of neurons in dissociated cell cultures of embryonic rat hippocampus expresses calbindin-D28k (Mr 28,000 calcium-binding protein) immunoreactivity and that these neurons are relatively resistant to neurotoxicity induced by either glutamate or calcium ionophore. Direct comparisons of dynamic aspects of intracellular calcium levels and calbindin-D28k immunoreactivity in the same neurons revealed that calbindin-D28k-positive neurons were better able to reduce free intracellular calcium levels than calbindin-D28k-negative neurons. These findings indicate that the differential expression of calbindin-D28k in hippocampal neurons occurs early in development and may be one determinant of selective neuronal vulnerability to excitotoxic insults.

Characterization of O-glycosylation sites in recombinant B-chain of platelet-derived growth factor expressed in yeast using liquid secondary ion mass spectrometry, tandem mass spectrometry and Edman sequence analysis

High-performance tandem mass spectrometry has been employed to structurally characterize intact O-linked glycopeptides and establish the complexity and extent of glycosylation for recombinant human platelet-derived growth factor B chain (rhPDGF-B) expressed in yeast. In addition, liquid secondary ion mass spectrometry (LSIMS) and Edman degradation have been employed to verify the protein sequence. LSIMS of high-performance liquid chromatographically fractionated proteolytic digests confirmed the complete amino acid sequence predicted by the human PDGF-B gene structure. Potential glycopeptides (as indicated by a mass shift of 162 or 324 Da from the mass of a predicted cleavage product) were sequenced using tandem mass spectrometry and Edman degradation. Ultraviolet matrix laser desorption mass spectrometry of rhPDGF-B dimer was used to determine the molecular weight distribution for the intact recombinant glycoprotein. In addition to the presence of unmodified peptides, corresponding peptides bearing monomannosyl moieties were found on serine 26 and threonines 20, 63, 88, 90 and 101. Further, dimannosyl moieties were found on threonines 6 and 63. These data reveal the presence of O-linked glycosylation at sites which do not fortify the concept of a consensus sequence involving proline residues, but which strengthen the concept of secondary and tertiary structure requirements. The advantages of high-energy collisionally induced dissociation analysis of O-linked glycopeptides over conventional base elimination and borohydride reduction and other mass spectrometric techniques are presented for the first time.

Induction of Crassulacean Acid Metabolism in the Facultative Halophyte Mesembryanthemum crystallinum by Abscisic Acid

The facultative halophyte, Mesembryanthemum crystallinum, shifts its mode of carbon assimilation from the C(3) pathway to Crassulacean acid metabolism (CAM) in response to water stress. In this study, exogenously applied abscisic acid (ABA), at micromolar concentrations, could partially substitute for water stress in induction of CAM in this species. ABA at concentrations of 5 to 10 micromolar, when applied to leaves or to the roots in hydroponic culture or in soil, induced the expression of CAM within days (as indicated by the nocturnal accumulation of total titratable acidity and malate). After applying ABA there was also an increase in phosphoenolpyruvate carboxylase and NADP-malic enzyme activities. The degree and time course of induction by ABA were comparable to those induced by salt and water stress. Electrophoretic analyses of leaf soluble protein indicate that the increases in phosphoenolpyruvate carboxylase activity during the induction by ABA, salt, and water stress are due to an increase in the quantity of the enzyme protein. ABA may be a factor in the stress-induced expression of CAM in M. crystallinum, serving as a functional link between stress and biochemical adaptation.

Prevention of invasive bacterial diseases by immunization with polysaccharide-protein conjugates

Covalent binding of CPS to T cell-dependent carrier proteins to form conjugates can be done by clinically acceptable methods. As a component of a conjugate, two immunologic properties of CPS are changed: 1) their immunogenicity is increased and; 2) reinjection induces a booster response in the young (T cell-dependence). Serum antibodies induced by the CPS alone, or as a component of a conjugate, are qualitatively similar: the difference between antibodies elicited by the CPS or the conjugate is quantitative. A clinical trial with a Hib-DT conjugate showed that conjugates could confer immunity in an age group not protected by the CPS alone. (table; see text) Induction of serum CPS antibodies confers protection against capsulated bacteria in the bloodstream: their role in the interaction of these pathogens on the mucous membranes has not been characterized. Preliminary in vitro experiments suggest that secretory antibodies to non-capsular structures may also exert protective immunity.

Liquid crystal adaptive lens: beam translation and field meshing

The liquid crystal adaptive lens (LCAL) is an electrooptic device that emulates a variable focal length lens. The LCAL focuses light by creating a parabolic refractive-index profile across the aperture of a liquid crystal cell. The focal length is electronically controlled by applying appropriate voltages to the array of independent electrodes, thus grading the refractive index of the liquid crystal material across the aperture. Beam translation perpendicular to the optical beam path is described theoretically and demonstrated. This capability coupled with the LCAL's programmable focal length allows 3-D beam control. Meshing, the smoothing of the refractive index between adjacent electrodes, is a critical parameter in achieving near diffraction-limited optical performance. Using two planar electrodes and a ground plane immersed in an isotropic dielectric as a model, a steady-state dc theoretical computer simulation is compared with experiment. Improvements in the liquid crystal cell design demonstrate improved performance over previous LCALs. A larger number of electrodes creates an image without spatial aliasing within the aperture.

Effect of denervation of carotid labyrinths on breathing in unrestrained Xenopus laevis

The effect of denervation of the carotid labyrinths on breathing responses to simultaneously applied aerial and aquatic normoxia, hypoxia, or hypercapnia has been studied in unrestrained Xenopus laevis. Denervation significantly reduced VI of normoxic toads compared with VI in intact and sham-operated toads, due to a significant reduction in the volume of each buccal pumping movement (VB) in denervates. Breathing increased significantly in response to environmental hypoxia or hypercapnia in intact and sham-operated toads as well as in denervates. Breathing frequency (fRESP) was the major determinant of the increase in VI for VB was unchanged and even fell slightly in denervates in hypercapnia. Dive time (DT) was significantly reduced in both hypoxia and hypercapnia, from that in normoxia. DT fell significantly more in hypoxia than in hypercapnia in both denervates and intact and sham-operated toads. It is concluded that the carotid labyrinth does not play a major role in regulating breathing in hypoxia or hypercapnia in unrestrained Xenopus.

Characterization of the polypeptide composition of human factor VIII:C and the nucleotide sequence and expression of the human kidney cDNA

Human coagulation factor VIII:C has been purified approximately 5000-fold from commercial preparations with an average activity yield of 35%. Proteins of 92 kD and 77-80 kD enriched during purification are precipitated by a human serum polyclonal antibody which inhibits factor VIII:C activity. Evidence suggests that these polypeptides are linked by a calcium ion bridge. Partial amino acid sequence information from these proteins has been obtained from the intact polypeptides and from products of digestion with thrombin, endoproteinase lysC, or trypsin after citraconylation. An oligonucleotide probe designed from one of the amino acid sequences was used to isolate a partial genomic clone from a human 4X chromosome library in bacteriophage lambda. The genomic segment was used to isolate two cDNA molecules encompassing the entire human kidney factor VIII:C mRNA. Biologically active factor VIII:C has been produced in a mammalian cell line utilizing a complete cDNA construction.

Serum antibody responses of juvenile and infant rhesus monkeys injected with Haemophilus influenzae type b and pneumococcus type 6A capsular polysaccharide-protein conjugates

Juvenile and infant rhesus monkeys were injected subcutaneously with saline solutions of Haemophilus influenzae type b (Hib) and pneumococcus type 6A (Pn6A) capsular polysaccharides conjugated to either tetanus toxoid (TT), horseshoe crab hemocyanin, or cholera toxin (CT), and the antibody responses of the monkeys to both bacterial components were measured. All three Hib conjugates were immunogenic and elicited booster responses; their comparative immunogenicity was Hib-CT greater than Hib-TT greater than Hib-horseshoe crab hemocyanin. Hib alone did not elicit antibodies in the juveniles. Juveniles responded earlier and with higher levels of antibodies than did infants. TT, as well as diphtheria-tetanus toxoids-pertussis vaccine adsorbed injected concurrently at a separate site, increased both Hib and TT antibody responses in juveniles (P less than 0.05). Concurrent injection of 5 Lf of fluid TT with a nonimmunogenic 5-micrograms dose in infants elicited levels of Hib antibodies comparable to those elicited by 50 micrograms of Hib-TT. Hib antibodies elicited by the conjugates remained at protective levels in both juveniles and infants 2 months after the last injection, were bactericidal, and conferred passive immunity against bacteremia in infant rats. Passive immunization of juveniles with tetanus immune globulin before each injection of Hib-TT did not suppress Hib antibodies. Hib-TT and Hib-CT elicited increases of Hib antibodies of the immunoglobulin M and G isotypes in the infants. The Pn6A-TT conjugate was considerably less immunogenic than the Hib-TT conjugate; only a few of the juveniles or infants responded with protective levels of Pn6A antibodies. Pn6A antibodies from responders conferred protection in mice against intraperitoneal challenge with Pn6A organisms. TT antibodies were elicited in both juvenile and infant animals after one injection of 50 micrograms of Hib-TT and in the infants injected with 5 micrograms of Hib-TT plus 5 Lf of TT; 5 micrograms of Hib-TT and Pn6A-TT in combination alone did not elicit TT antibodies. Hib-CT elicited CT antibodies in both juveniles and infants.

A comparison of high-energy accelerator depth dose data

Accurate depth dose information is necessary for the use of high-energy radiotherapy photon beam units. It would be useful, therefore, to have one set of published data available for each different type unit manufactured to which physicists can compare their measured data. Pertinent questions are raised regarding the similarity between accelerators and their central axis depth dose characteristics, the availability of adequate published central axis depth dose data, and the minimum amount of data needed to determine the applicability of published data to a particular machine. Data taken by the Radiological Physics Center (RPC) for 4-10 MV units are analyzed and compared with published data in an attempt to answer these questions.

Further studies on the immunogenicity of Haemophilus influenzae type b and pneumococcal type 6A polysaccharide-protein conjugates

Conjugates were prepared by carbodiimide-mediated coupling of adipic acid hydrazide derivatives of Haemophilus influenzae type b (Hib), Escherichia coli K100, and pneumococcal 6A (Pn6A) polysaccharides with tetanus toxoid (TT), as an example of a "useful" carrier, and horseshoe crab hemocyanin (HCH), as an example of a "nonsense" carrier. These conjugates were injected into NIH mice, and their serum antibody responses to the polysaccharides and proteins were characterized. As originally reported, Hib conjugates increased the immunogenicity of the capsular polysaccharide and elicited greater than the estimated protective levels of anti-Hib antibodies in most recipients after one injection and in all after the third injection (Schneerson et al., J. Exp. Med. 152:361-376, 1980). Both Hib conjugates induced similar anti-Hib responses. The K100-HCH conjugate was more immunogenic than the K100-TT conjugate and elicited anti-Hib responses similar to the Hib conjugates after the third injection. Simultaneous injection of the K100 and the Hib conjugates did not enhance the anti-Hib response. The Pn6A-TT conjugate induced low levels of anti-Hib antibodies; when injected simultaneously with the Hib conjugates, the anti-Hib response was enhanced, as all mice responded after the first injection and with higher levels of anti-Hib than observed with the Hib conjugates alone (P < 0.05). The Pn6A conjugates were not as immunogenic as the Hib conjugates. Pn6A-TT was more effective than was Pn6A-HCH; it elicited anti-Pn6A (>100 ng of antibody nitrogen per ml) in 6 of 10 mice after the third injection. The addition of the Hib-HCH conjugate to the Pn6A-TT conjugate increased the anti-Pn6A response with a higher geometric mean antibody titer, and 9 of 10 mice responded after the third injection. A preparation of diphtheria toxoid, TT, and pertussis vaccine increased the anti-Hib antibody levels after the first injection only in mice receiving Hib-TT, but not in mice receiving Hib-HCH, suggesting that additional carrier protein (TT) enhanced the anti-polysaccharide response. Simultaneous injection of Hib and Pn6A conjugates with the same or different carriers resulted in an enhanced serum antibody response to each polysaccharide. The anti-tetanus toxin response reached protective levels (>0.01 U/ml) in most mice after the first injection and in all mice after the second and third injections of TT conjugates. A progressive increase in the anti-HCH response with each additional injection was noted in animals receiving HCH conjugates. Animals receiving the diphtheria toxoid-TT-pertussis vaccine preparation responded with a greater increase in anti-carrier antibody than those receiving the conjugates alone. This method of synthesis provided conjugates capable of inducing protective levels of antibodies to both the polysaccharides and carrier proteins.

Chemical cocarcinogenesis with the use of a subclone derived from Balb/3T3 cells with catechol as cocarcinogen

This study was performed for the detection of cocarcinogens by transformation in vitro with the use of a subclone of a Balb/3T3 cell line. Dose response, cytotoxicity, and transformation studies were done with the use of an indirect-acting carcinogen, benzo[a]pyrene (B[a]P), a direct-acting alkylating carcinogen, beta-propiolactone (BPL), and the mouse skin cocarcinogen catechol. The rate of transformation was notably higher in groups treated with B[a]P and catechol or BPL and catechol than in groups treated with either B[a]P or BPL. Catechol alone did not induce any transformation. All the cells isolated from the transformed foci showed characteristics of malignantly transformed cells, such as anchorage-independent growth. Thus chemical cocarcinogenesis was accomplished in vitro similar to that accomplished in in vivo studies reported earlier on mouse skin.

Metabolic fate of nitrosoproline in the rat

The metabolism of [U14C]nitrosoproline and [carboxyl-14C]-nitrosoproline was studied in the rat. In most experiments, less than 1% of the administered radioactivity appeared as radioactive CO2 in the expired air, and urinary excretion of radioactivity was rapid and almost complete as the unchanged compound, which was the only radioactive component detected in the urine. The absence of any radioactive urinary components corresponding to proline or its metabolites indicated that no detectable metabolic denitrosation had occurred. Studies of the disappearance of nitrosoproline from the circulating plasma indicated an apparent volume of distribution of 52% of the total body weight, suggesting some penetration by the compound into the intracellular space. There was no significantly detectable covalent binding of radioactivity from the labeled nitrosoproline to DNA ro RNA of the liver and only an extremely low level of binding to liver protein. Taken with the reported noncarcinogenicity of nitrosoproline in rodents, the above findings suggest that proline may be a suitable nitrosatable substrate for use in tests of endogenous nitrosation reactions in animals and human subjects.