Antimalarials for control of disseminated granuloma annulare in children.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to M Simon.
Explore the source record for details and available documents.
BACKGROUND: Purpura pigmentosa chronica is an inflammatory skin disorder probably caused by an allergic reaction. Delayed-type hypersensitivity or immunocomplex vasculitis has been considered as a possible mechanism. OBJECTIVE: Detailed analysis of cell adhesion molecule (CAM) modulation may give further insights into the pathogenesis and underlying immune reaction of this disease. METHODS: By immunohistochemical techniques we investigated the in situ expression of integrins, selectins, and CAMs of the immunoglobulin superfamily. RESULTS: Infiltrating lymphocytes expressed LFA-1, LFA-2, VLA-4, and VLA-5, whereas some of the macrophages were also positive for p150/95 and MAC-1. VLA-1 was found on lymphocytes near the basement membrane of the epidermis. Compared with uninvolved or healthy skin endothelial cells showed upregulation of ICAM-1, VCAM-1, and, focally, E-selectin. Some fibroblasts were positive for ICAM-1. ICAM-1 was also upregulated on lesional keratinocytes that also expressed alpha 2, alpha 3, and alpha 6 integrin chains on basal and suprabasal epidermal layers. CONCLUSION: Our findings demonstrate characteristic modifications in the expression of CAMs in purpura pigmentosa chronica and indicate the involvement of the epidermis in this disease. This modulation shows close parallels to those described for chronic delayed-type immune reactions of the skin.
OBJECTIVE: HIV-1 and HIV-2 isolates representing various geographic regions and distinct viral subtypes were examined for their ability to establish both in vitro and in vivo productive infections of Macaca nemestrina (pigtail macaque) peripheral blood mononuclear cells. METHODS: Animals were inoculated with either autologous cell-associated or cell-free viral preparations of selected isolates. HIV-specific immune responsiveness, hematologic changes, genetic variation, and virus burden were monitored as delineators of HIV pathogenesis. RESULTS: HIV-2 replication in vitro and in vivo correlated with nascent antigen production and rising viral titers as determined by infectious center assays. Infection was detectable by polymerase chain reaction amplification of proviral sequences in macaque cells as early as 1 week postinoculation. Two distinct patterns of CD4+ cell depletion induced by HIV-2 infection were observed during the first month postinoculation and characterized by a moderate loss sustained through 20 weeks postinoculation or a substantial loss maintained long-term (> 90 weeks). Identity between inoculating viral stocks and subsequent viral isolates from animals was established comparatively by limited sequence analysis of specific domains within the HIV-2 pol and env genes. In contrast, replication of HIV-1 isolates was limited or only semipermissive in vitro. Intravenous inoculation of HIV-1 field isolates, using conditions successful for HIV-2 (for example, identical viral titers), failed to establish a productive viral infection leading to seroconversion of fluctuations in hematologic cell markers. Infection with a high-titer inoculum of a laboratory-adapted HIV-1 strain in vivo, as demonstrated by polymerase chain reaction analysis, produced seroconversion in the absence of overt viral replication or hematologic variations in one out of four animals. CONCLUSIONS: This system provides for multifaceted modeling of HIV pathogenesis, primarily with HIV-2 and potentially with HIV-1/-2 chimerics, in support of immunotherapeutic developments and critical evaluation of intervention practices.
Interleukin (IL) 10 is a recently discovered cytokine, originally isolated from T-helper 2 (Th2) cells, which inhibits cytokine production of T-helper 1 (Th1) cells. Because Th1 cells appear to be of importance during the contact hypersensitivity reaction (CHS) we hypothesized that IL-10 might modulate the outcome of CHS in vivo. Intraperitoneal injection of murine recombinant IL-10 (1000 ng) into naive mice 24, 72, or 120 h before sensitization by epicutaneous application of 2,4-dinitrofluorobenzene (DNFB) did not affect ear swelling when ears were challenged 5 d later. However, intraperitoneal injection of IL-10 into already sensitized mice 24 h before challenge resulted in a significant suppression of the ear swelling response, suggesting that under the conditions employed IL-10 is able to block the effector phase, but not the induction phase of CHS in vivo. The suppression could be reversed by the concurrent injection of an IL-10 antibody. Moreover, heat inactivation of native IL-10 resulted in loss of the inhibitory capacity. When mice were sensitized by subcutaneous injection of trinitrophenyl-coupled spleen cells (DTH) instead of epicutaneous application of the hapten (CHS), intraperitoneally-injected IL-10 suppressed the effector phase, but also the induction phase of DTH. IL-10 did not inhibit the toxic ear-swelling response induced by topical application of two irritants tested (croton oil or benzalkonium chloride). The capacity of IL-10 to suppress the effector phase of CHS and DTH supports an important role for this cytokine in the downregulation of type IV immune reactions in vivo. The finding that IL-10 suppresses the induction of DTH, but not of CHS, further suggests that CHS and DTH are related but distinct immune reactions.
Cytotoxic monoclonal antibody IVA 44 was generated after the intraperitoneal immunization with peripheral blood mononuclear (PBM) cells and the boost by the intrasplenic inoculation of skin graft. The detected membrane antigen isolated by immunoprecipitation appears to be composed of two subunits characteristic for the MHC class I molecules. The antibody IVA 44 exhibited a different reactivity: it recognized the BoLA A14 (A8) specificity in animals typed in the Fifth BoLA workshop, while it reacted with all A8 positive animals including subtypes A14 and A15 in Czech and Slovak cattle. It is concluded that mAb IVA 44 might detect the broad subtype of A8 covering A14 and certain A15 split(s). The diverse A15 reactivity of this mAb in the workshop and our population could be explained by the different occurrence of A15 splits in both populations.
1. The pharmacological characteristics of the kappa-opioid receptor agonist, EMD 60400, have been investigated, with particular reference to its central and peripheral sites of action and its ability to influence nociception. The kappa agonists ICI 197067 and ICI 204448 were tested for purposes of comparison. 2. EMD 60400 and ICI 197067 bind with high affinity (IC50 values of 2.8 and 1.5 nM, respectively) and high selectivity to kappa-opioid receptors. ICI 204448 has a lower binding affinity (IC50 13.0 nM) and selectivity for kappa-opioid receptors. 3. EMD 60400, ICI 197067, and ICI 204448 are full and potent agonists in the rabbit vas deferens in vitro assay for kappa-opioid receptors (IC50 values of 41.8, 15.7 and 15 nM, respectively). 4. Ex vivo binding experiments in mice revealed that EMD 60400 and ICI 197067 were well taken up after s.c. administration. Brain levels of EMD 60400 were lower than those of ICI 197067 at comparable doses, indicating that EMD 60400 does not penetrate into the CNS as well as ICI 197067. 5. Haloperidol-induced DOPA accumulation in the nucleus accumbens of the rat was dose-dependently reversed by s.c. application of EMD 60400 and ICI 197067 at doses of and above 3 and 0.3 mg kg-1, respectively. ICI 204448 had no effect on DOPA accumulation at 30 mg kg-1, s.c. 6. Prolongation of hexobarbitone-induced sleeping time in mice and motor impairment in the rat rotarod test were observed for EMD 60400 at doses above 3 and 2.5 mg kg-1, s.c., respectively, and for ICI 197067 at doses above 0.3 and 0.25 mg kg-1, s.c., respectively. ICI 204448 was inactive in these tests at doses of 30 and 100 mg kg-1, s.c., respectively.7. EMD 60400 applied s.c. produced dose-dependent naloxone-reversible antinociception in the mouse formalin test (1st and 2nd phase ID50 0.44 and 0.47 mg kg-1, respectively) and rodent writhing test (ID50 mouse 0.55 mg kg-1 and rat 0.3mg kg-1). Furthermore, EMD 60400 was considerably more potent in the rat pressure pain test after the induction of inflammation with carrageenin than under normalgesic conditions (ID50 values 0.1 Microg kg-1 and 4.0 mg kg-1, s.c., respectively). The action of EMD 60400 (50 microgkg-1, s.c.) in the hyperalgesic pressure pain test was completely antagonized by injection of the K-opioid antagonist, norbinaltorphimine (100 microg) into the inflamed tissue, thus demonstrating the peripheral opioid nature of this effect.8. EMD 60400 produced dose-dependent inhibition of neurogenic plasma extravasation elicited byantidromic electrical stimulation of the rat saphenous nerve (ID50 value 0.3 mg kg-1, i.v.). This inhibition was completely antagonized by intraplantar injection of norbinaltorphimine (50 microg).9. EMD 60400, ICI 197067, and ICI 204448 have diuretic effects in rats at doses of and above 0.1, 0.01,and 0.3 mg kg-1, s.c., respectively. An antidiuretic action was also observed with ICI 197067 at very low doses (3 and 6 microgkg-1, s.c.).10. Pharmacological and biochemical data therefore indicate that the three K-opioid receptor agonists tested here have different tendencies to elicit centrally-mediated sedation and putative aversion(ICI 197067 > EMD 60400 > ICI 204448) which correspond to their ability to cross the blood-brain barrier. EMD 60400 combines high affinity and selectivity for the K receptor with a degree of peripheral selectivity. The peripheral actions of systemically-applied EMD 60400 against hyperalgesic pressure pain and neurogenic inflammation are very probably mediated by opioid receptors on the endings of sensory nerve fibres.
1. The pharmacological properties of the novel diarylacetamide kappa-opioid receptor agonist, EMD 61753, have been compared with those of ICI 197067 (a centrally-acting kappa agonist) and ICI 204448 (a peripherally-selective kappa agonist). 2. EMD 61753 binds with high affinity (IC50 5.6 nM) and selectivity (kappa:mu:delta:sigma binding ratio 1:536:125: > 1,786) to kappa-opioid receptors and is a full and potent (IC50 54.5 nM) agonist in an in vitro assay for kappa-opioid receptors (rabbit vas deferens preparation). 3. Systemically-applied [14C]-EMD 61753 is found in high concentrations in the lungs, liver, adrenal glands and kidneys. Considerably less radioactivity is detected in the whole brain, and this radioactivity is concentrated in the region of the cerebral ventricles in the choroid plexuses. EMD 61753 penetrates only poorly into the CNS. 4. EMD 61753 was weakly effective in pharmacological tests of central activity. This compound reversed haloperidolol-induced DOPA accumulation in the nucleus accumbens of the rat only at a dose of 30 mg kg-1, s.c., (doses of 0.1, 1.0 and 10 mg kg-1, s.c., and 1.0, 10 and 100 mg kg-1, p.o., were inactive). Hexobarbitone-induced sleeping in mice was prolonged by EMD 61753 at threshold doses of 10 mg kg-1, s.c., and 100 mg kg-1, p.o., whereas the motor performance of rats in the rotarod test was impaired by EMD 61753 with an ID50 value of 453 mg kg-1, s.c. 5. EMD 61753 produced dose-dependent, naloxone-reversible antinociception in the mouse formalin test (1st phase ID50 1.9 mg kg-1, s.c., and 10.4 mg kg-1, p.o.; 2nd phase ID50 0.26 mg kg-1, s.c., and 3.5 mg kg-1, p.o.) and rodent abdominal constriction test (ID50 mouse 1.75 mg kg-1, s.c., and 8.4 mg kg-1, p.o.; ID50 rat 3.2 mg kg-1, s.c., and 250 mg kg-1, p.o.). EMD 61753 was inactive, or only weakly effective, in the rat pressure test under normalgesic conditions. After the induction of hyperalgesia with carrageenin, however, this compound elicited potent, dose-dependent (ID50 0.08 mg kg-1, s.c., and 6.9 mg kg-1, p.o., after remedial application, and 0.2 mg kg-1, s.c., and 3.1 mg kg-1, p.o., after prophylactic application) and naloxone-reversible antinociception. The antinociceptive action of systemically-applied (50 mg kg-1, p.o.) EMD 61753 in the hyperalgesic pressure test was completely inhibited by injection of the K-opioid antagonist norbinaltorphimine (100 Lg) into the inflamed tissue, a result which indicates that this opioid effect is mediated peripherally.6. Cutaneous plasma protein extravasation produced by antidromic electrical stimulation of the rat saphenous nerve was dose-dependently inhibited by systemically-applied EMD 61753 (ID13 values 3.7 mg kg-1, s.c., and 35.8 mg kg-1, p.o.), and this effect was completely antagonized by intraplantar application of norbinaltorphimine (50 microg). Extravasation elicited by the intraplantar application of substance P (10 microg) was not influenced by the administration of EMD 61753.7. EMD 61753 produced dose-dependent diuresis in non-hydrated rats at doses of and above 1.0 mg kg-1, s.c., and 10 mg kg-1, p.o., and in saline-loaded rats at doses of and above 10 mg kg-1, s.c.,and 30mgkg-1, p.o.8. The prostaglandin-mediated fall in mean arterial blood pressure elicited in anaesthetized rats by i.v.application of arachidonic acid was not inhibited by prior treatment with EMD 61753 (10mg kg-1,p.o.). Thus, a blockade of prostaglandin synthesis via inhibition of cyclo-oxygenase activity does not contribute to the in vivo effects of EMD 61753 and its metabolites.9 The present experiments therefore indicate that EMD 61753 is a potent, selective and orally-effective full ic-opioid receptor agonist which has a limited ability to penetrate the blood-brain barrier and elicit centrally-mediated sedation, putative aversion, diuresis, and antinociception. The inhibitory actions of systemically-applied EMD 61753 against hyperalgesic pressure nociception and neurogenic inflammation are mediated peripherally, probably by opioid receptors on the endings of sensory nerve fibres.
OBJECTIVES: To assess the diagnostic value for rheumatoid arthritis (RA), of an immunoblotting assay based on the rat oesophagus epithelium antigens recognised by the so-called 'antikeratin antibodies' ('AKA'), antigens that have been identified as three non-cytokeratin proteins (referred to as A, B and C proteins). METHODS: After polyacrylamide gel electrophoresis in non-denaturing conditions and electrotransfer of an epithelial extract, the immunoreactivities to the A, B and C proteins of a series of serum samples from 88 patients with RA and 100 patients with non-rheumatoid rheumatic diseases, were semiquantitatively evaluated. RESULTS: A total of 81.8% of RA serum samples recognised the three proteins, while 91% of non-RA serum samples only weakly recognised the A and B proteins but not the C protein. Only in the group of RA patients, were the titres of the antibodies to the A, B and C proteins found to be significantly correlated with each other and with the titres of 'AKA' detected by the standard indirect immunofluorescence (IIF) method. For a diagnostic specificity of 99%, the diagnostic sensitivities of the detection of the A and B proteins were 50% and 43.2%, respectively, when those of the detection of 'AKA' by IIF and of IgM-rheumatoid factor by enzyme-linked immunosorbent assay were 42% and 54%, respectively. In contrast, at a same specificity of 99%, the diagnostic sensitivity of the detection of the C protein was significantly higher with a value of 70.5%. CONCLUSION: This immunoblotting assay which is the first immunochemical method proposed for the detection of 'AKA, should be validated on larger series of patients but can already be considered as a very powerful test for the serological diagnosis of RA.
Proopiomelanocortin (POMC), the precursor for melanotropic, corticotropic, and opioid peptides such as alpha-melanocyte-stimulating hormone (alpha MSH), ACTH, and other related peptides, was originally identified as a product of the pituitary gland. However, recent evidence shows that POMC products can also be produced by nonpituitary tissues. Because keratinocytes, the major constituent of the epidermis exhibit the capacity to release a variety of proinflammatory and immunomodulatory mediators, the present study was performed to investigate whether human keratinocytes are able to produce POMC-derived peptides. Supernatants of human normal keratinocytes and an epidermal carcinoma cell line (A431) contained significant levels of immunoreactive alpha MSH and ACTH. Upon immuneprecipitation and size-exclusion chromatography, keratinocyte-derived alpha MSH exhibited a molecular mass of approximately 1 kD and was biologically active as demonstrated in a tyrosinase bioassay. Northern blot analysis revealed the expression of POMC-specific transcripts (1.3 kb) in both normal keratinocytes and A431 cells. The production of alpha MSH and ACTH could be significantly upregulated both at the protein and mRNA level upon treatment with phorbol myristate acetate, ultraviolet light, or interleukin 1. These data provide first evidence that human keratinocytes produce POMC-derived peptides such as alpha MSH and ACTH. Because POMC-derived peptides recently have been recognized as potent immunomodulatory mediators, their presence in the epidermis may have a major impact on the skin immune system.
In the present study, an analysis was made of the expression pattern of thrombospondin-1 (TSP1) and its receptor (CD36) in skin biopsies obtained from healthy volunteers and from patients with lichen planus, lupus erythematosus, cutaneous T-cell lymphoma and psoriasis vulgaris. Using monoclonal antibodies against TSP1 in biopsies from the healthy volunteers and from both clinically involved and uninvolved skin of the patients, a specific peroxidase-positive reaction was detected around the sweat glands in the dermis. In all cases investigated, the CD36-positive lesional keratinocytes remained TSP1-negative. These findings favour the hypothesis that CD36-positive keratinocytes might have some functional relevance via oxidized low-density lipoprotein and/or collagen fibrils, without any connection with TSP1.
Explore the source record for details and available documents.
OBJECTIVES: To determine attitudinal predictors of health-care providers' willingness to treat HIV-infected patients. We also tested the hypothesis that differences between dental and medical students in their expressed desire to treat HIV-infected patients result from differences in their clinical exposure to bloodborne pathogens and their clinical training. DESIGN: A cross-sectional design was used to administer a self-report questionnaire format to preserve subject anonymity. METHODS: A questionnaire was used to assess attitudes, knowledge, and behavior associated with the care of HIV-infected patients. Both bivariate statistics and logistic regression techniques were used to determine factors related to the desire to treat HIV-infected patients. RESULTS: Compared with dental students, medical students expressed a greater desire to treat HIV-infected patients. However, the attitudinal predictors of a desire to treat were similar across both groups. The two most important predictors were the degree to which respondents perceived a personal risk of HIV exposure and their sense of professional obligation to treat all patients. Furthermore, knowledge levels were unrelated to desire to treat. CONCLUSIONS: These results suggest that educational interventions aimed simply at increasing a provider's knowledge of HIV may not be effective in changing behavior.
The human genome contains a family of endogenous retroviruses, HERV-K, with sequence homology to the B-type mouse mammary tumor virus (MMTV). We have detected HERV-K-LTR related cDNA clones by screening a human placenta cDNA library with a HERV-K LTR probe. Three of the isolated cDNA clones were characterized by nucleotide sequencing. The analyzed clones did not contain any retroviral sequences other than those related to HERV-K LTRs, but were found to be coexpressed with cellular sequences. Furthermore, transcripts containing HERV-K LTR sequences were demonstrated by Northern blotting and PCR in human leukemic and normal white blood cells, as well as in various tumor cell lines, indicating abundant transcription of solitary HERV-K LTRs in human tissues. In patients with lymphatic leukemias, a transcript of about 6 kb hybridizing with HERV-K LTR was detected that was not found in patients with myelogenous leukemias or in healthy persons.
In summary, it can be expected that the availability of unrelated donors will increase the number of CML patients that can be treated curatively with allogeneic BMT. Hydroxyurea has replaced busulfan as first line treatment in CML since it prolongs survival. Ongoing randomized studies comparing IFN-based treatment regimens with standard chemotherapy or IFN-monotherapy probably will answer the question whether IFN can cure a small percentage of CML patients and whether this small percentage can be increased by additional chemotherapy. The present attempts to improve prognostic scores and to apply them to early treatment decisions will allow treatment adaptation more individually. The implications of endogenous retroviral sequences expressed in CML cells are not known now, but may be far reaching.
Kin28 is an essential serine-threonine kinase of Saccharomyces cerevisiae. Multicopies of a novel cyclin gene, CCL1, are able to suppress the thermosensitivity of two kin28-ts mutants. The CCL1 gene is not cyclically transcribed, yet its product is also essential for cell proliferation. Furthermore, when overexpressed under high expression promoter, Cell is able to replace G1 function of Cln cyclins. Cell and Kin28 are physically associated in vivo. Therefore, like p34CDC28/cdc2, Kin28 may be a cyclin dependent kinase which is required for cell proliferation.
Explore the source record for details and available documents.
The Hin recombinase catalyzes site-specific inversion of DNA. Chemical and genetic studies on Hin binding to the recombination sites indicates that both major and minor DNA groove interactions are critical. In order to determine the molecular nature of these interactions, we have crystallized a synthetically derived 52 amino acid peptide consisting of the DNA binding domain of Hin with a 14 base-pair oligonucleotide representing a recombination half-site. This communication presents preliminary diffraction and analysis of these cocrystals and a packing model for the complex within the crystal.
To obtain a broad spectrum of mutations in the POL3 gene, we have developed an efficient random mutagenesis procedure. Partially extended, primed, single-stranded templates were used for forced misincorporation of non-complementary nucleotides, extended to completion and ligated. Linear fragments of the resulting amplified mutagenized library were then used to transform a Saccharomyces cerevisiae strain by the marker replacement technique. This procedure has proven to be very efficient when applied to the C-terminal moiety of POL3, yielding 24 temperature-sensitive mutants and six extragenic revertants.