How do measurement duration and timing interact to influence estimation of basal physiological variables of a nocturnal rodent?

Metabolic rate and evaporative water loss are two commonly measured physiological variables. It is therefore important, especially for comparative studies, that these variables (and others) are measured under standardised conditions, of which a resting state during the inactive phase is part of the accepted criteria. Here we show how measurement duration and timing affect these criteria and impact on the estimation of basal metabolic rate (oxygen consumption and carbon dioxide production) and standard evaporative water loss of a small nocturnal rodent. Oxygen consumption, carbon dioxide production and evaporative water loss all decreased over the duration of an experiment. Random assortment of hourly values indicated that this was an animal rather than a random effect for up to 11h. Experimental start time also had a significant effect on measurement of physiological variables. A longer time period was required to achieve minimal carbon dioxide consumption and evaporative water loss when experiments commenced earlier in the day; however, experiments with earlier start times had a lower overall estimates of minimal oxygen consumption and carbon dioxide production. For this species, measurement duration of at least 8h, ideally commencing between before the inactive phase at 03:00h and 05:00h, is required to obtain minimal standard values for physiological variables. Up to 80% of recently published studies measuring basal metabolic rate and/or evaporative water loss of small nocturnal mammals may overestimate basal values due to insufficiently long measurement duration.

Comparison of the reliability and validity of outcome instruments for cutaneous dermatomyositis.

BACKGROUND: Reliable and validated measures of skin disease severity are needed for cutaneous dermatomyositis (DM). Cutaneous Dermatomyositis Disease Area and Severity Index (CDASI), Dermatomyositis Skin Severity Index (DSSI) and Cutaneous Assessment Tool (CAT) skin indices have been developed as outcome instruments. OBJECTIVES: We sought to demonstrate reliability and validity of the CDASI, and to compare the CDASI with other potential tools for use in measuring disease severity in cutaneous dermatomyositis. PATIENTS AND METHODS: CDASI has four activity and two damage measures, with scores from 0 to 148. DSSI assesses activity based on body surface area and severity on a scale of 0-72. CAT uses 21 activity and damage items, for a range of 0-175 for activity and 0-33 for damage. Ten dermatologists used the instruments to score the same 12-16 patients in one session. Global validation measures were administered to physicians and patients. RESULTS: Global validation measures correlated with the three outcome instruments (P < 0.0001). CAT displayed lower inter- and intrarater reliability relative to the CDASI. All scales correlate better with physician than patient global skin measures. CONCLUSIONS: It appears that the CDASI may be a useful outcome measure for studies of cutaneous DM. Further testing to compare responsiveness of all three measures is necessary.

Scleroderma gene expression and pathway signatures.

Gene expression studies in scleroderma have shown large and consistent changes in the gene expression of end-target tissues. These changes reflect the lymphocyte infiltration and pathway deregulation potentially linked to disease pathogenesis. Gene expression in scleroderma also reflects the clinical heterogeneity in the disease and can be used to categorize patients. Contained within these gene expression signatures are groups of genes that could serve as biomarkers for clinical end points and disease activity. The use of mechanism-derived gene expression signatures in scleroderma will provide a better understanding of the deregulated pathways contributing to disease pathogenesis.

Dermatology position paper on the revision of the 1982 ACR criteria for systemic lupus erythematosus.

The 1982 ACR classification criteria have become de facto diagnostic criteria for systemic lupus erythematosus (SLE), but a review of the criteria is necessary to include recent diagnostic tests. The criteria were not developed with the help of dermatologists, and assign too much weight to the skin as one expression of a multiorgan disease. Consequently, patients with skin diseases are classified as SLE based mostly on skin symptoms. We discuss specific problems with each dermatologic criterion, but changes must await a new study. We suggest the following guidelines for such a study, aimed at revision of the criteria. 1) The SLE patient group should be recruited in part by dermatologists. 2) The study should evaluate an appropriate international ethnic/racial mix, including late onset SLE as well as pediatric patients. 3) All patients should have current laboratory and clinical evaluations, as suggested in the paper, to assure the criteria can be up-to-date. This includes anti-SS-A and anti-SS-B antibodies and skin biopsies for suspected cutaneous lupus erythematosus except for nonscarring alopecia and oral ulcers. 4) The study should be based on a series of transparent power calculations. 5) The control groups should represent relevant differential diagnoses in numbers large enough to assess diagnostic problems that might be specific to these differential diagnoses. In order to demonstrate specificity of the criteria with a 95% confidence interval between 90 and 100%, each control group of the above should have at least 73 patients.

Aberrant serum hyaluronan and hyaluronidase levels in scleroderma.

BACKGROUND: Scleroderma, or systemic sclerosis, is characterized by aberrations of extracellular matrix deposition. These changes parallel early stages of wound healing when increased deposition of hyaluronan (HA) and collagen occur. Both processes result ultimately in the formation of fibrotic scar tissue. Activities of HA synthase and hyaluronidase, the enzymes that synthesize and degrade HA, are critical in HA turnover. Both become elevated whenever increased matrix deposition occurs. HA deposition occurs early in wound healing, and increases are documented in the circulation of scleroderma patients. We postulated that elevated HA and hyaluronidase may both be indicators of early-stage disease in scleroderma, in parallel with early changes observed in wound healing. In an attempt to reduce HA accumulation and the associated fibrosis in scleroderma tissues, topical and intravenous hyaluronidase administrations have been used in the past as treatment modalities, with occasional success. This also suggested that hyaluronidase enzyme activity is involved in the disease process. It is now recognized that the hyaluronidases constitute an enzyme family. The somatic hyaluronidase Hyal-1 is the only activity present in human serum. OBJECTIVES: To determine levels of HA and Hyal-1 in the sera of scleroderma patients at various stages of their disease. METHODS: Levels of HA and Hyal-1 activity were determined in 25 scleroderma patients. Subjects were separated into two groups, those in the early stage with duration of disease of 2 years or less, and late-stage patients with disease duration of more than 2 years. RESULTS: In early-stage scleroderma, levels of HA were elevated significantly, as predicted, in comparison with late-stage patients and controls. Late-stage levels of HA were comparable with those found in control sera. By contrast, levels of Hyal-1 activity were normal in early-stage patients, similar to those in controls, but were decreased in late-stage patients, falling even below those of controls. CONCLUSIONS: We have confirmed that circulating levels of HA are elevated in scleroderma, but show for the first time that such elevations occur predominantly in early-stage disease. Patients with late-stage disease have decreased serum Hyal-1 activity, perhaps reflecting decreased levels of HA turnover. This study also represents the first time that hyaluronidase activity levels have been determined in scleroderma patients.

Dysregulation of transforming growth factor beta signaling in scleroderma: overexpression of endoglin in cutaneous scleroderma fibroblasts.

OBJECTIVE: As an initial approach to understanding the basis of the systemic sclerosis (SSc; scleroderma) phenotype, we sought to identify genes in the transforming growth factor beta (TGF beta) signaling pathway that are up-regulated in lesional SSc fibroblasts relative to their normal counterparts. METHODS: We used gene chip, differential display, fluorescence-activated cell sorter, and overexpression analyses to assess the potential role of TGF beta signaling components in fibrosis. Fibroblasts were obtained by punch biopsy from patients with diffuse cutaneous SSc of 2-14 months' duration (mean 8 months) and from age- and sex-matched healthy control subjects. RESULTS: Unexpectedly, we found that fibroblasts from SSc patients showed elevated expression of the endothelial cell-enriched TGF beta receptor endoglin. Endoglin is a member of the nonsignaling high-affinity TGF beta receptor type III family. The expression of endoglin increased with progression of disease. Transfection of endoglin in fibroblasts suppressed the TGF beta-mediated induction of connective tissue growth factor promoter activity. CONCLUSION: SSc is characterized by overproduction of matrix; that is, genes that are targets of TGF beta signaling in normal fibroblasts. Our findings suggest that lesional SSc fibroblasts may overexpress endoglin as a negative feedback mechanism in an attempt to block further induction of profibrotic genes by TGF beta.

Structure-based design of caspase-1 inhibitor containing a diphenyl ether sulfonamide.

A series of compounds was designed and prepared as inhibitors of interleukin-1beta converting enzyme (ICE), also known as caspase-1. These inhibitors, which employ a diphenyl ether sulfonamide, were designed to improve potency by forming favorable interactions between the diphenyl ether rings and the prime side hydrophobic region. An X-ray crystal structure of a representative member of the diphenyl ether sulfonamide series bound to the active site of caspase-1 was obtained.

Celecoxib-induced Sweet's syndrome.

Sweet's syndrome and related neutrophilic dermatoses have been associated with a variety of medications. Celecoxib is a new cyclo-oxygenase-2 inhibitor recently approved for arthritis. We describe a 57-year-old man who experienced tender pustulopapular lesions on the dorsal aspects of the hands, neck, and legs 1 week after starting celecoxib. Histopathologic examination of the lesion showed a diffuse dermal neutrophilic infiltrate, edema of the papillary dermis, spongiform pustules, and no leukocytoclastic vasculitis. These findings were consistent with Sweet's syndrome. Without realizing a possible association, the patient rechallenged himself with a second course of the medication, which resulted in a rapid exacerbation of his lesions. After discontinuing the medication for the second time, the patient has had complete clearing of his lesions. To our knowledge, this is the first report of Sweet's syndrome associated with this new class of nonsteroidal anti-inflammatory drugs.

Sjogern's syndrome.

Sjogren's syndrome (SS) is a systemic autoimmune exocrinopathy that affects the salivary and lacrimal glands. It typically presents as the "sicca complex" of dry eyes (xerophthalmia) and dry mouth (xerostomia) along with other symptoms such as arthritis. SS is classified as either primary or secondary. In the primary form, dry eyes and dry mouth occur alone. In the secondary form, the dry eyes and dry mouth occur in the context of another rheumatic disease, most commonly rheumatoid arthritis. There is an increasing list of systemic manifestations affecting the lung, kidney, and nervous system in patients with SS. The skin is affected in half of SS patients. Despite this high frequency of cutaneous involvement, patients with SS are not commonly seen in dermatology practices. SS is underrecognized and underdiagnosed because the cutaneous manifestations are nonspecific (eg, xerosis, pruritus) and less severe than the oral, ocular, or musculoskeletal symptoms. Nonetheless, because of its high prevalence, risk of cutaneous vasculitis, and the increased risk of a lymphoproliferative disorder, it is important for dermatologists to be familiar with SS.

Detection of type 1 cytokines in discoid lupus erythematosus.

BACKGROUND: Although multiple studies suggest a dysregulated T-cell cytokine production in systemic lupus erythematosus, the cytokine profile in discoid lupus erythematosus (DLE) lesions is unknown. OBJECTIVES: To characterize the cytokine profile in DLE by immunohistochemical and molecular methods, and to investigate the role of cytokines in the pathogenesis of DLE. DESIGN: Patients were evaluated clinically, and biopsy specimens of lesional skin were examined by light microscopy. Reverse transcriptase-polymerase chain reaction and immunohistochemical analysis were performed on 11 biopsy specimens. We investigated the presence of interleukin (IL) 2, interferon gamma (IFN-gamma), IL-4, tumor necrosis factor alpha, (TNF-alpha), and IL-1beta messenger RNA (mRNA) in 8 biopsy specimens of DLE and compared it with 3 biopsy specimens of normal skin. SETTING: Academic referral research hospital. PATIENTS: Eight consecutive patients with a clinical and histologic diagnosis of DLE. RESULTS: Localized DLE was found in 7 patients and widespread in 1. During the 4 years of the investigation, none of the patients developed systemic lupus erythematosus. We found significantly elevated levels of IL-2 and IFN-gamma mRNA in all 8 biopsy specimens of DLE; in contrast, no transcripts of IL-2 or IFN-gamma were detected in 3 biopsy specimens of normal skin (P<.01). Similarly, elevated levels of TNF-alpha mRNA were detected in 8 DLE biopsy specimens, while no TNF-alpha mRNA was detected in 3 biopsy specimens of normal skin (P<.01). No IL-4 or IL-1 beta mRNA was detected in 8 biopsy specimens of DLE lesional skin and 3 biopsy specimens of normal patient skin. Immunohistochemical analysis showed increased staining for IL-2 and IFN-gamma receptors, while no detectable IL-4 receptor was found. No cytokine mRNA or cytokine receptor protein was detected in biopsy specimens of normal skin. CONCLUSIONS: These findings suggest that DLE is associated with type 1 cytokines characterized by the expression of IL-2 and IFN-gamma. Type 1 cytokines may be critical for induction, development, and maintenance of DLE.

Enhanced lymphoproliferation and diminished autoimmunity in CD4-deficient MRL/lpr mice.

MRL/lpr mice spontaneously develop an autoimmune disease with features of systemic lupus erythematosus. They also develop a lymphoproliferative disorder characterized by a massive accumulation of double-negative (DN) T cells that lack both CD4 and CD8. To clarify the role of CD4 in autoimmunity and lymphoproliferation in these mice, CD4-deficient MRL/lpr mice were generated. CD4-deficient MRL/lpr mice developed massive expansion of DN T cells in the blood, spleen, and lymph nodes, which significantly exceeded the degree of lymphoproliferation in CD4-expressing control MRL/lpr mice. Despite this lymphoproliferation, CD4-deficient MRL/lpr mice produced little, if any, antibodies to double-stranded DNA, and they had prolonged survival relative to CD4-expressing littermates. However, they eventually developed moderately severe nephritis, characterized by immunoglobulin and complement deposition in glomeruli, vasculitis, and renal infiltration by CD8+ T cells. These findings indicate that (1) lymphoproliferation in MRL/lpr mice does not require the expression of CD4; (2) autoantibody production in MRL/lpr mice is dependent on the expression of CD4 and not on the accumulation of DN T cells; and (3) the development of nephritis in MRL/lpr mice involves both CD4-dependent and CD4-independent mechanisms.

The pathogenesis of cutaneous fibrosis.

Cutaneous fibrosis is an integral component of a variety of human disorders including keloids, hypertrophic scar, and most notably, scleroderma. Each has its own etiology and unique clinical characteristics, but all involve the dysregulation of connective tissue metabolism, in particular, the activation of dermal fibroblasts. In this review, we examine various molecular events in scleroderma that may lead to fibroblast activation, and propose a new model to explain the persistence of such activation by scleroderma fibroblasts in the apparent absence of exogenous stimuli.

Cutaneous innervation density in the allodynic form of postherpetic neuralgia.

The relationship between deafferentation, sensory function, and pain was explored in 18 subjects with chronic postherpetic neuralgia (PHN). Subjective thresholds for warmth, cooling, and heat pain were measured quantitatively in painful skin areas and compared with normal contralateral skin. The severity of allodynia was graded in the affected area. Two 3-mm punch biopsies were taken from the most painful skin area and one from unaffected contralateral mirror-image skin. Immunofluorescence with the axonal marker PGP 9.5 revealed a reduction in density of innervation of the epidermis, the dermal-epidermal junction, and the eccrine sweat glands in PHN skin. In painful PHN skin, the reduction in innervation density was positively correlated with the magnitude of the thermal sensory deficits. However, loss of cutaneous innervation was inversely correlated with allodynia, indicating that surviving cutaneous primary afferent nociceptors that are spontaneously active and/or sensitized contribute to PHN pain and allodynia.

The histopathologic spectrum of palisaded neutrophilic and granulomatous dermatitis in patients with collagen vascular disease.

BACKGROUND AND DESIGN: Patients with lupus erythematosus, rheumatoid arthritis, and other diseases in which circulating immune complexes occur can develop a papular eruption on the extremities. Terms including Churg-Strauss granuloma, cutaneous extravascular necrotizing granuloma, rheumatoid papules, superficial ulcerating rheumatoid necrobiosis, and interstitial granulomatous dermatitis with arthritis have been given to this entity. We evaluated the clinical and histopathologic features of six patients with systemic lupus erythematosus, two patients with rheumatoid arthritis, and one patient with an incompletely characterized collagen vascular disease who developed cutaneous papules. RESULTS: The lesions were located largely on the extremities and were symmetrically distributed in most of the patients. They ranged from a few to many and from skin colored to erythematous, and they had smooth, ulcerated, or umbilicated surfaces. Histopathologic examination showed a spectrum of changes that, we believe, reflect the evolution of lesions, ie, leukocytoclastic vasculitis with dense neutrophilic infiltrates and degenerated collagen in early lesions; palisaded granulomas surrounding leukocytoclastic debris, fibrin, and altered collagen in fully developed lesions; and, as the process wanes, palisaded granulomas with dermal fibrosis and scant neutrophilic debris. Each stage of development elicits a different differential diagnosis, which can be resolved by the application of histopathologic criteria. CONCLUSION: The histopathologic findings are consonant with the evolution of an immune complex-mediated disease. The diverse histopathologic, and sometimes clinical, appearances account for the variety of names given to this condition. We propose the name palisaded neutrophilic and granulomatous dermatitis of immune complex disease to reflect the histopathologic evolution and clinical aspects of this condition.

Treatment of murine lupus with monoclonal antibodies to lymphocyte function-associated antigen-1: dose-dependent inhibition of autoantibody production and blockade of the immune response to therapy.

Monoclonal antibodies (mAb) to lymphocyte function-associated antigen-1 (LFA-1) have been used successfully in vivo to inhibit immune responses and to block inflammatory reactions. To determine whether these effects of anti-LFA-1 could retard autoimmune disease, we treated lupus-prone NZB/NZW F1 (B/W) mice with a rat mAb to LFA-1 (anti-CD11a). Mice received high-dose therapy (500 micrograms twice weekly), low-dose therapy (40 micrograms thrice weekly), or phosphate-buffered saline from age 5 months to age 10 months. Treatment with high doses of anti-CD11a suppressed both the immune response to the rat mAb and the production of autoantibodies to double-stranded DNA. In contrast, treatment with low doses of anti-CD11a elicited an immune response to the rat mAb and did not suppress autoantibody production. The immunosuppressive effects of high doses of anti-CD11a were not due to target cell depletion. In fact, treatment induced a marked lymphocytosis which involved all lymphocyte subsets equally. Despite inhibiting autoantibody production, high-dose therapy had only modest effects on longevity.