A human Ro/SS-A autoantigen is the homologue of calreticulin and is highly homologous with onchocercal RAL-1 antigen and an aplysia "memory molecule".

The Ro/SS-A (Ro) autoantigens consist of at least four immunologically distinct proteins which are recognized by autoantibodies typically found in sera from patients with primary Sjogren's syndrome and in subsets of patients with lupus erythematosus. We recently isolated a 1.9-kb human cDNA clone which encodes one of these Ro autoantigens. Synthetic oligonucleotides corresponding to the human Ro sequence were used to amplify the homologous gene from a murine B cell cDNA library using the polymerase chain reaction. The mouse cDNA-encoded amino acid sequence was found to be 94% homologous to the human Ro sequence and is 100% homologous to murine calreticulin, a high affinity calcium-binding protein which resides in the endoplasmic and sarcoplasmic reticulum. The amino acid sequence of rabbit calreticulin is 92% homologous to both murine calreticulin and human Ro. Onchocerca volvulus and Drosophila melanogaster also have molecules that are highly homologous to human Ro. In addition, human Ro has a molecular mass, isoelectric point, and significant amino acid sequence similar to the Aplysia californica snail neuronal protein 407. These homologies suggest that this Ro protein has a very basic cellular function(s) which may in part involve calcium binding.

Immunologic reactions after experimental cryosurgery to the reproductive system of the male rabbit. I. The humoral response.

Single cryoinjuries to the accessory reproductive organs and to the gonads of normal adult male rabbits elicit antibody responses in 35.8 and 11.9 per cent of the cases, respectively. The antibodies display agglutinating and precipitating properties against extracts of the organ that underwent the freezing injury, but do not react in the presence of extracts of other organs of the rabbit. Repeated cryoinjuries raise both the percentage of reacting animals (up to 100 per cent after four successive cryostimulations, in some cases) and the titer of the humoral responses, which, in addition, endure longer in blood than do responses to single stimuli. These humoral phenomena are the expression of immunologic reactions mounted by the host animals against "self" components, regarded, however, as "nonself" by their surveillance apparatus.

Antinuclear antibodies: clinical correlations and biologic significance.

Several trends become evident from the foregoing discussion. As the different ANA antigenic specificities have been identified, they have often been found to be highly conserved polypeptides that subserve very basic cellular functions that are carried out in the nucleus, nucleolus, and ribosomes. The reasons why only 30 or so basic cellular proteins become the targets of an autoimmune response in patients with connective tissue disease at the exclusions of the other 10,000 macromolecules that exist inside cells remain a mystery. However, some insight into this enigma might be provided by the mechanism of molecular mimicry (Table 9). The possibility that highly conserved immunogenic molecules that are expressed by infectious pathogens can trigger an immune response in a genetically predisposed human host that cross-reacts with cellular autoantigens is a well documented phenomenon in disorders such as rheumatic fever. This mechanism is now being mentioned with increasing frequency in discussions pertaining to the pathogenesis of autoimmune connective tissue diseases. Another trend relates to the increasing sensitivity of the newer assays that have been developed to detect ANA. When highly purified or recombinant autoantigens are used in versatile assays such as ELISA, radioimmunoassays, or immunoprecipitation, the frequency with which certain autoantibodies can be detected in patient subgroups can go up significantly. For example, with classical immunodiffusion, anti-Ro/SS-A antibodies can be detected in 25% of unselected patients with SLE, whereas with an ELISA based on affinity purified Ro/SS-A antigen, 50% of patients with SLE are found to have elevated levels of this autoantibody specificity. As is often the case, we pay for increased sensitivity in a laboratory test with decreased specificity. With immunodiffusion, virtually no normal individuals have anti-Ro/SS-A antibodies, but with the ELISA as many as 10% of normals have elevated anti-Ro/SS-A binding levels. Thus, the incremental diagnostic value of this newer anti-Ro/SS-A assay could be questioned. The true clinical value of this new laboratory technology will become more evident when these more sophisticated ANA assays are used together in a panel-like fashion to profile a given patient's autoimmune response at the very onset of his illness. Preliminary work has already begun in this area. This approach, if well standardized, could have significant diagnostic and prognostic value. Another benefit of this newer technology will be the ability to measure antibody binding levels to individual autoepitopes--limited portions of an autoantigen's amino acid sequence that represent single antibody binding sites. It is possible that certain patterns of clinical disease could be linked to autoantibody production against individual autoepitopes rather than whole autoantigenic molecules. This area is only now beginning to be explored.

Delayed type hypersensitivity to intralesional triamcinolone acetonide.

Corticosteroids are the most widely used class of drugs in dermatology. In the past, allergic contact dermatitis to topical corticosteriods was rarely reported. In this article, we present a case of delayed type hypersensitivity to triamcinolone acetonide.

Cerebral intraventricular lipoma and sudden death.

A lipoma in the left lateral cerebral ventricle of a 73-year-old male is reported. This rather infrequently occurring lesion was an incidental finding in the patient's postmortem examination and probably accounted for the acute hydrocephalus that lead to his sudden death.

The confined space-hypoxia syndrome.

Two meter readers of a local water company were found dead in an underground water meter pit. Studies revealed a decrease in oxygen and an increase in carbon dioxide in the pit as a result of aerobic microorganisms present in the pit. Such an atmosphere may be rapidly fatal to the unwary worker who frequents such an environment. It is of paramount importance that this occupational hazard be recognized so that preventative measures may be established. We propose that the term "Confined Space-Hypoxia Syndrome" be adopted to all such confined space accidents occurring in water meter pits, tanks, holds of ships, mines, underground storage bins, and so forth, resulting from oxygen-deficient atmospheres. A series of recommended preventative procedures is included.

Modeling of organic pollutant destruction in a stirred-tank reactor by ozonation.

Destruction of organic contaminants in water by ozonation is a gas-liquid process which involves ozone mass transfer and fast irreversible chemical reactions. Ozonation reactor design and process optimizing require the modeling of the gas-liquid interactions within the reactor. In this paper a theoretical model combining the fluid dynamic and reaction kinetic parameters is proposed for predicting the destruction rates of organic pollutants in a semi-batch stirred-tank reactor by ozonation. A simple expression for the enhancement factor as our previous work has been applied to evaluate the chemical mass transfer coefficient in ozone absorption, 2,4-dichlorophenol (2,4-DCP) and 2,6-DCP or their mixture are chosen as the model compounds for simulating, and the predicted DCP concentrations are compared with some measured data.

Clinical relevance of antibodies to Ro/SS-A and La/SS-B in subacute cutaneous lupus erythematosus and related conditions.

Ro/SS-A autoantibodies are frequently associated with subacute cutaneous lupus erythematosus, neonatal lupus erythematosus and Sjögren's syndrome. The Ro/SS-A autoantigen is a ribonucleoprotein complex consisting of at least four protein components and four small cytoplasmic RNA components designated hY RNA 1, 3, 4 and 5. Three of the Ro/SS-A peptides have been isolated and cloned. The function of this ribonucleoprotein complex is as yet unknown.

Combined Fontana-Masson/Perls' staining.

A procedure that allows successive staining of tissue sections with the Fontana-Masson technique for melanin and Perls' technique for hemosiderin is described.

Disseminated cryptococcosis and sudden death. Report of an autopsy case.

We report a case of sudden death due to terminal cryptococcal pneumonia in a patient not suspected to have AIDS. The correct diagnosis was found only by microscopic examination and serologic workup, illustrating the hazards faced by forensic pathologists and their assistants working without adequate information about the bodies under study. This case illustrates the need for the highest levels of caution and compliance with universal precautionary measures during autopsy procedures in the present days of the AIDS epidemic.

Sclerotic primary cutaneous leiomyosarcoma.

We describe the case of a painful primary cutaneous leiomyosarcoma that developed on the back of a 54-year-old white male over a 6-year period. The lesion had been sampled by punch technique and had been originally diagnosed as cutaneous sclerosis. Histologic examination of excisional tissue revealed a diffuse spindle cell neoplasm in the dermis that extended into the subcutis. There was extensive sclerosis and sparse cellularity in the deep portion and in several zones throughout the tumor. Immunostaining for desmin was negative, although stains for vimentin and smooth muscle actin were both strongly positive. Sclerotic cutaneous leiomyosarcoma should be recognized as a distinct but unusual variant of leiomyosarcoma that may be difficult to diagnose because of extensive sclerosis. Lesions may be painful and should be considered in the differential diagnosis of painful cutaneous neoplasms of the skin.

Impact of ultraviolet irradiation on expression of SSA/Ro autoantigenic polypeptides in transformed human epidermal keratinocytes.

SSA/Ro autoantibodies are frequently found in various autoimmune disorders including subacute cutaneous and neonatal lupus erythematosus. SSA/Ro patient sera precipitate a ribonucleoprotein complex consisting of multiple polypeptides and small RNA molecules (hY RNA). Such sera react in Western blot with at least four antigenically distinct proteins having molecular weights of 52-60 kD. Several laboratories have reported increased binding of anti-SSA/Ro patient serum to viable cultured human epidermal keratinocytes following UVB irradiation. However, it is currently unknown which SSA/Ro molecule(s) might be responsible for this increased antibody binding to UVB irradiated keratinocytes. To address this question, we studied the effect of UVB irradiation on the expression of three different polypeptide components of the SSA/Roautoantigen complex (60 kD SSA/Ro, 52 kD SSA/Ro, and 46 kD SSA/Ro (calreticulin) in A431 cells, a transformed human epidermal keratinocytes cell line. Total cellular and cell surface expression of each SSA/Ro antigenic polypeptide was examined by a whole cell ELISA and FACS using rabbit anti-synthetic peptide antisera as probes. Our results suggest that both total cellular and cell surface calreticulin, but not the 60 and 52 kD SSA/Ro polypeptides, is increased after 100 J/M2 of UVB irradiation, indicating that perturbed calreticulin expression may be primarily responsible for the UVB-induced increased binding of anti-SSA/Ro to keratinocytes. These results suggest that calreticulin could be a critical component of the SSA/Ro ribonucleoprotein complex that is involved in the pathogenesis of anti-SSA/Ro-associated photosensitive LE skin lesions.

Impact of ultraviolet radiation on the cellular expression of Ro/SS-A-autoantigenic polypeptides.

Modulation of Ro/SS-A autoantigens in epidermal keratinocytes has been implicated in the pathogenesis of photosensitive forms of Ro/SS-A-antibody-associated cutaneous lupus erythematosus (LE) such as subacute cutaneous LE and neonatal LE. Since Ro/SS-A ribonucleoprotein particles have recently been shown to be very complex molecular structures, we have performed studies to determine whether the expression of three of the Ro/SS-A antigenic polypeptides might be differentially regulated in transformed human epidermal keratinocytes following UVB radiation. Our findings indicate that both total cellular and cell surface levels of calreticulin are upregulated by UVB exposure more so than are either the 52- or 60-kD Ro/SS-A antigens. These results suggest that calreticulin could be a critical component of the Ro/SS-A ribonucleoprotein complex involved in the pathogenesis of Ro/SS-A-antibody-associated LE skin lesions.

Comparative bioavailability of two fluconazole capsule formulations in healthy volunteers.

This work reports the bioavailability of two fluconazole (CAS 86386-73-4) capsule formulations in 24 healthy volunteers of both sexes who received a single oral dose (150 mg). The study was conducted using an open, randomized, two-period crossover design with two-week washout interval. Plasma samples were obtained up to 168 h after drug administration and fluconazole concentration were analyzed using electrospray tandem mass spectrometry coupled to liquid chromatography. The pharmacokinetic parameters obtained for fluconazole after the administration of each formulation included the area under the curve (AUC)(0-168 h), AUC(0-infinity), maximum concentration (Cmax), time to reach Cmax (Tmax), elimination constant (Ke) and half-life (T1/2). The 90% confidence interval for the geometric mean of the individual ratio test formulation/reference formulation were 97.18-108.60% for AUC0-168 h), 90.87-111.11% for AUC(0-infinity), 104.88-114.88% for Cmax 90.38-136.79% for Ke, 91.87-108.93% for T1/2 and (-)1.5-(-)0.10 for Tmax (for individual differences). Since for both Cmax or AUC the 90% CI are within the interval proposed by the Food and Drug Administration (FDA), the test formulation (Zoltrix) is bioequivalent to the reference formulation for both the rate and the extent of absorption after single dose administration.

The systemic lupus erythematosus (SLE) disease autoantigen-calreticulin can inhibit C1q association with immune complexes.

Following its release from cells during infection and inflammation, calreticulin (CRT) can act as an autoantigen in diseases such as SLE. Why CRT is a target of protective immunity and whether it may interfere with innate immunity once released from cells during inflammation is unclear. In the present study, we found that CRT was detected more frequently in SLE sera and in higher amounts than found in control sera. Approximately 40% of SLE sera tested contained autoantibodies against CRT as detected by ELISA and immunoblotting. CRT was found to be predominantly in the sera of SLE patients associated with immune complexes and C1q, and only bound to the surfaces of neutrophils in the presence of low levels of calcium and magnesium. In order to further investigate the C1q-CRT interaction, recombinant CRT and its discrete domains (N-, P-, and C-domains) were produced in Escherichia coli. CRT binds to globular head region of C1q primarily via its N- and P-domains. The N-domain was shown to be the most autoantigenic region of CRT, as the anti-CRT autoantibodies from most patients reacted against this region. CRT also altered C1q-mediated immune functions. The P-domain of CRT bound to C1q and reduced the binding of immune complexes in SLE sera to immobilized C1q. Full length CRT and its N- and P-domains were able to reduce the C1q-dependent binding of immune complexes to neutrophils and solid-phase bound C1q. We conclude that CRT, once released from leucocytes during inflammation, may not only induce an antigenic reaction, but also interfere with C1q-mediated inflammatory processes.

Calreticulin is released from activated neutrophils and binds to C1q and mannan-binding protein.

The Ca2+ storage protein calreticulin is associated with the endoplasmic reticulum and shares a high degree of amino acid homology with the surface receptor C1q-R. In this study, flow cytometric analysis detected calreticulin on the neutrophil surface, which decreased during stimulation probably as a consequence of shedding, as calreticulin was found by ELISA in the cell supernatants of stimulated cells. Antibodies raised against C1q-R and calreticulin demonstrated a high degree of immunological cross-reactivity for purified calreticulin as determined by dot blot analysis. Western blots of neutrophil subcellular fractions located calreticulin in both the cytosol and cell membrane fractions; C1q-R was largely confined to the cell membrane. Calreticulin and C1q-R both bind to C1q and mannan-binding protein. Therefore, calreticulin may be shed on cell activation and may be associated with the cell membrane, where it can potentially interact with C1q and serum lectins. The implications of this are discussed.