Antibacterial and antibiofouling clay nanotube-silicone composite.

INTRODUCTION: Invasive medical devices are used in treating millions of patients each day. Bacterial adherence to their surface is an early step in biofilm formation that may lead to infection, health complications, longer hospital stays, and death. Prevention of bacterial adherence and biofilm development continues to be a major healthcare challenge. Accordingly, there is a pressing need to improve the anti-microbial properties of medical devices. MATERIALS AND METHODS: Polydimethylsiloxane (PDMS) was doped with halloysite nanotubes (HNTs), and the PDMS-HNT composite surfaces were coated with PDMS-b-polyethylene oxide (PEO) and antibacterials. The composite material properties were examined using SEM, energy dispersive spectroscopy, water contact angle measurements, tensile testing, UV-Vis spectroscopy, and thermal gravimetric analysis. The antibacterial potential of the PDMS-HNT composites was compared to commercial urinary catheters using cultures of E. coli and S. aureus. Fibrinogen adsorption studies were also performed on the PDMS-HNT-PEO composites. RESULTS: HNT addition increased drug load during solvent swelling without reducing material strength. The hydrophilic properties provided by PEO were maintained after HNT addition, and the composites displayed protein-repelling properties. Additionally, composites showed superiority over commercial catheters at inhibiting bacterial growth. CONCLUSION: PDMS-HNT composites showed superiority regarding their efficacy at inhibiting bacterial growth, in comparison to commercial antibacterial catheters. Our data suggest that PDMS-HNT composites have potential as a coating material for anti-bacterial invasive devices and in the prevention of institutional-acquired infections.

Open comparison study of oxidative stress markers between patients with chronic renal failure in conservative therapy and patients in haemodialysis.

AIMS: Oxidative stress is defined as tissue damage caused by an imbalance between the excessive production of the oxidant components and an insufficient defence mechanism. It has been observed, as in patients with chronic kidney failure, that there exists a pro-oxidant state characterised by a higher level of reactive oxygen species (ROS), and that oxidative stress in dialysis patients can be aggravated by the activation of neutrophils associated with the production of free radicals. In patients undergoing dialysis even the molecules other than those of cytokines can accumulate and provoke an inflammatory response. This study proposes an analysis based on the total antioxidant capacity (TAC), thiol concentration (TC) and pro-oxidant capacity (POC) in the serum of various groups of patients: one group of dialysis subjects who had been undergoing substitutive treatment for more than ten years at the time of the study; one group of subjects with chronic renal insufficiency in its pre-terminal stage and subjected to conservative therapy; and the control group consisting of healthy volunteers. MATERIALS AND METHODS: Three types of tests were employed to assess the level of oxidative stress: oxy-adsorbent test, d-ROMS test, and SHp- test. Thirty-three subjects were selected: 11 undergoing haemodialysis for over then years; 14 patients with chronic kidney failure in its pre-terminal stage, and 8 normal subjects. In patients undergoing renal substitutive treatment, the serum levels (mean±sd) of TAC were 272.98±20.54; TC, 249.19±92.48, and POC, 95.06±15.70. In patients with chronic renal insufficiency in its pre-terminal stage and undergoing conservative treatment, the value of TAC was 226.5±27.89; TC, 336.42±102.08; and POC, 80.78±15.69. The levels of TAC in the serum of the controls were 335.62±46.35; TC, 434.09±22.23; and POC, 56.31±7.41. CONCLUSION: The analysed data suggest that in dialysis the patients with chronic kidney failure, whether undergoing conservative therapy during its pre-terminal stage or in substitution treatment during its terminal stage, there is a reduction in the antioxidant defence (in terms of TAC and thiolic barrier) and an increase in POC compared to the healthy subjects in the control group. Uraemia and haemodialysis increase the inflammatory response: an initial signal provokes the inflammatory state with the production of cytokines and free radicals or reactive oxygen, so that the lack of an antioxidant defence mechanism can bring about a vicious circle with the continual production of other free radicals.

Assessment of the oxidative stress markers in patients with chronic renal insufficiency undergoing dialysis treatment.

AIMS: Uraemia is a disease characterised by a significant oxidative stress, and it is a wide agreement that oxidative stress which accompanies uraemia, increases the inflammatory state and promotes the alterations of tiny molecules such as amino acids, proteins, lipids, and carbohydrates. There are numerous records of how ROS are connected to the pathology of end stage renal disease (ESRD). The aim of this study is to assess the Total Antioxidant Capacity (TAC), the Thiolic Capacity (TC) and the Pro-Oxidant Capacity (POC) in the serum of patients undergoing dialysis treatment. MATERIALS AND METHODS: Forthy-six patients have been recruited (32 men, 14 women; mean age 68.5±15.8) who received hemodialytic treatment triweekly. Three methods have been used: oxy adsorbent test (mmol/l) to determine TAC values; d-ROM test (mg/100 mg/H2O2) to determine POC; SHp-test (mmol/l) to determine TC. RESULTS: In patients who underwent hemodialysis, TAC levels were: pre-dialysis, 265.9±30.5; post-dialysis, 300.0±40.6; TC levels: pre-dialysis, 267.4±59.1; post-dialysis, 303.2±116.7; POC levels: predialysis, 86.2±16.9; post-dialysis, 98.6±17.0; NS: TAC, 335.6±46.3; TC, 434.0±22.2; POC, 56.3±7.4. TAC in both pre- and post-dialysis is reduced compared to the NS (p < 0.05); moreover TAC increases after dialysis (p < 0.05). Pre- and post-dialysis TC is reduced compared to NS (p < 0.05); available TC increases after dialysis, although not statistically significant. Pre- and post-dialysis POC in patients undergoing dialysis is increased compared to the NS (p < 0.05); moreover, POC tends to increase after dialysis ( p < 0.05). The data obtained from our study also show that the TAC is reduced in the patients subjected to hemodialysis compared to the NS, both before and after dialysis treatment; TAC increased after dialysis, even though it did not reach the level of the control group. CONCLUSION: Our study has demonstrated that exists a profound imbalance between antioxidants and the production of ROS in ESRD patients, which determines oxidative stress and eventually leads to atherosclerosis and cardiovascular complications. This, in turn, represents the major cause of morbidity and mortality in these patients.

Oxidant/antioxidant status in patients with chronic HIV infection.

The infection caused by HIV leads to an activation of the immune system, which involves local and systemic oxidative stress. In HIV-positive (HIV+) patients, oxidative damage is the result of HIV infection and its progression through the replication of the virus. We have examined 52 subjects: 26 HIV+ patients, and 26 healthy subjects (NC). Analysis of the parameters of the oxidant/antioxidant status (total antioxidant capacity (TAC), hydroperoxides (free radicals, PRO), thiols as thiolic capacity, TC) was carried out by means of the OXY-Absorbent test, the d-Rom test, and the -SHp test, respectively. Healthy subjects presented the following values: TAC (micromol/ml) 259.5+/-40.5; TC (micromol/l) 434.09+/-18.31; PRO (mg/dl) 54.09+/-7.3; CD4+ cells (cells/ml) 850+/-333. Values of HIV+ patients were the following: TAC 218.73+/-18.55 (ns vs NC; TC 250.88+/-93.11 (p 0.001 vs NC); PRO 110.5+/-23.61 (p 0.0005 vs NC); CD4+ cells 354+/-323.35 (p 0.0005 vs NC). The statistical analysis shows a direct correlation between TAC vs CD4+ cells; an indirect correlation between hydroperoxides vs CD4+ cells; not significant result between thiolic capacity vs CD4+ cells; finally, good correlations between TAC, hydroperoxides, and thiolic capacity vs HIV-RNA. The data obtained have proven that HIV+ patients present a condition of important oxidative stress. We may affi rm that this disease concurs with an increase of extreme stress; a condition in which the antioxidant defences are present, but are insufficient in neutralising the damaging actions of reactive species of oxygen, thus contributing to an acceleration in the natural history of HIV infections.

Study of bone metabolism in patients with chronic HIV infection.

AIMS: Various studies have confirmed the high incidence of skeletal homeostasis modifications in subjects who are carriers of chronic HIV infections, and specific pharmacological treatments, which modify the metabolism and condition both the weight loss and the reshaping of the bones. The presence of a reduction in body mass index seems to contribute to the progressive deterioration of the skeletal framework. The aim of this study was to see whether the presence of HIV-seropositivity could constitute a risk factor for the development of osteoporosis/osteopenia, even in the light of the fact that our group was composed of patients with a concentrated age span well under the limit for both post-menopausal and senile osteoporosis, and with a median age superimposable for both sexes. MATERIALS AND METHODS: Our study involved 26 HIV+ patients with an average duration of infection equal to 6.7 +/- 4.8 years, and a range of seropositive duration between 6 months to 16 years. The prominent ultrasonometrical parameters are as follows: Broadband Ultrasound Attenuation, Speed of Sound, Stiffness Index or Quantitative Ultra-sound Index, Bone Mineral Density, and T-score. The biochemical study was carried out by assessing a marker of neoformation such as seric osteocalcine, and uninary pyridinoline and deoxipyridonoline as resorption markers. RESULTS: The results confirmed the presence of osteoporosis/osteopenia in 46% of the samples (11%, and 35%, respectively), with a progressive reduction in bone mineral density in relation to the duration of HIV infection. Assessment of the marker for bone metabolism showed a significant increase in osteocalcine in the female population compared to the males, without any significant variations in the normal values. CONCLUSIONS: Extreme variability in the morphological appearance at bone level during the course of HIV infection would lead us to believe that in the genesis of various forms, depending on the mechanisms and the time involved only in the parts defined, other attributable factors are responsible, not only for the progression of the core pathology and the possible interference of hormonal factors (behavioural and/or nutritional) directly correlated with the state of infection, but also for the dismetabolic effects of the antiretroviral drugs.

Functional assessment of patients with systemic sclerosis by the use of 'Six-minutes-walking-test'.

AIMS: Systemic Sclerosis (SS) is a chronic inflammatory disease of the connective tissues, characterised by alterations in the functions and structures of the small blood vessels (capillaries and arterioles) and by modifications associated with the disposition of collagen in the tissues. One of the most frequent complication of the SS is the pulmonary arterial hypertension (PAH). Aim of this study was to assess the various pathophysiological relationships betweens SS and PAH in order to establish whether the presence of this systemic disease can represent a risk factor. MATERIALS AND METHODS: Ten patients affected by SS (9 women and 1 man, with a mean age of 55.7 +/- 11.4 years) were enrolled in our study, as inpatients at Dept. of Internal Medicine and Rheumatology Unit of Perugia University School of Medicine in the "Santa Maria" General Hospital in Terni, Italy. A control group of 10 clinically healthy subjects (CHS, 9 women and 1 man, ranging in age from 35 to 55 years) was also recruited in order to obtain normal clinical data of reference In subjects recruited, we have conducted a functional evaluation, based on physical tests (6-minute-walking-test, 6MWT), equipment and laboratory, on subjects suffering from SS with suspected PAH, in order to calculate the degree of cardio-pulmonary compromission brought on by this disease, taking into consideration important variables such as age and gender. RESULTS: The 6 MWT showed that the mean value at rest of the O2 saturation (%) was 97.1 +/- 1.20, heart rate (hr/min) 76 +/- 8.8, and respiratory rate (rr/min) 20.4 +/- 2.8. HS had 98.6 +/- 0.52, 75.7 +/- 6.86, and 16.8 +/- 1.61, respectively. After the the test, the results showed that the patients had O2 saturation 93.8 +/- 3.42, hr 113 +/- 20.27, and rr 31 +/- 2.86. HS had 97.6 +/- 0.69, 90.7 +/- 5.67, and 20.1 +/- 1.59, respectively. CONCLUSIONS: Our study has confirmed the high involvement of PAH and other cardio-respiratory disturbances in patients with SS. In fact, we have verified PAP to be above the normal range in 3 out of 10 patients, while the other 3 patients presented borderline values. Because it is a simple method to conduct at low cost, in addition to being non-invasive, reproducible and well accepted, we must affirm that the 6MWT should be more utilized and exploited, especially during the fi rst phases of diagnosis. This in turn can help us to assess the patients and to determine a course of treatment which is more complex and onerous, as in therapeutic monitoring for verifying efficacy.

Evaluation of oxidative stress in rheumatoid and psoriatic arthritis and psoriasis.

INTRODUCTION: The aim of the present study is to discuss the importance of the processes of oxidative stress in the pathogenesis of certain autoimmune diseases, to search for an appropriate assessment marker, and to debate current approaches which have been proposed for the treatment of Rheumatoid Arthritis (RA), Psoriatic Arthritis (PsA), and Psoriasis (Ps). MATERIALS AND METHODS: The total antioxidant capacity (TAC), the thiolic capacity (TC), and the serum hydroperoxide concentration (SHC) were measured in 37 subjects: 13 with RA, 8 with PsA, 8 with Ps, and 8 healthy controls. RESULTS: SHC levels were significantly higher in patients with RA (p = 0.01), as well as in those with PsA (p = 0.005) and Ps (p = 0.002) in comparison with the control group. However, a significant reduction in the TAC values in the serum of all three groups (RA, p = 0.03; PsA, p = 0.005; Ps, p = 0.001) were observed in comparison with the healthy controls. The thiolic concentration were found to have significantly diminished in patients with RA (p =0.0005) and Ps (p = 0.0005) in comparison with the control group. Our findings have brought out the fact that the therapeutic treatment of RA using biological drugs is more than satisfactory in accord with the considerable increase in the TAC values, although not significantly, compared to those patients treated with DMARDs. CONCLUSIONS: The determination of the parameters of oxidative stress utilising these methods may be useful as a quick test, and as routine in monitoring the state of oxidative stress in patients suffering from RA, PsA, and Ps, so that a more effective treatment for ROS can be undertaken accordingly. The administration of biological drugs seems to have a role in increasing the mechanism of the barrier which the body possesses against oxidative stress.

Application of Staphylococcal enterotoxin B on normal and atopic skin induces up-regulation of T cells by a superantigen-mediated mechanism.

BACKGROUND: The skin of patients with inflammatory skin diseases such as atopic dermatitis is frequently colonized with Staphylococcus aureus. Colonization with S aureus has been reported to exacerbate atopic dermatitis. Recent studies have demonstrated that S aureus isolated from the skin of patients with atopic dermatitis releases bacterial toxins that act as superantigens. We have previously applied the staphylococcal superantigen staphylococcal enterotoxin B (SEB) on intact human skin and found that the application led to induction of dermatitis. OBJECTIVE: The purpose of the study was to determine whether superantigen-induced dermatitis is primarily due to a T cell-superantigen-mediated reaction or represents nonspecific cytokine-driven inflammation. METHODS: We applied SEB, vehicle, and sodium lauryl sulfate on normal skin in healthy (n = 6) and atopic subjects (n = 6) and biopsy specimens were taken from all treated areas. The biopsy specimens from all subjects and peripheral blood from the atopic subjects were analyzed for the T-cell receptor (TCR) Vbeta repertoire with mAbs against TCR Vbeta 2, 3, 8.1, 12, 14, and 17. RESULTS: From all subjects, both healthy and patients with atopic dermatitis, skin biopsy specimens from SEB-treated areas demonstrated selective accumulation of T cells expressing SEB-reactive TCR Vbeta 12 and 17 (P <.05). This selective up-regulation was not found in the sodium lauryl sulfate-treated areas. CONCLUSION: Our data strongly support that superantigen-induced T-cell activation is involved in the dermatitis seen after experimental application of SEB on intact skin.

Epidermal HLA-DR and the enhancement of cutaneous reactivity to superantigenic toxins in psoriasis.

Streptococcal and staphylococcal superantigens (SAg's) have been implicated in the pathogenesis of inflammatory skin diseases, but the mechanisms by which these toxins act are unknown. The present study assessed the ability of nanogram quantities of topically applied purified toxic shock syndrome toxin-1 (TSST-1), staphylococcal enterotoxin type B, and streptococcal pyrogenic enterotoxin types A and C to induce inflammatory reactions in clinically uninvolved skin of normal controls and subjects with psoriasis, atopic dermatitis, and lichen planus. These SAg's triggered a significantly greater inflammatory skin response in psoriatics than in normal control subjects or in subjects with atopic dermatitis or lichen planus. Surprisingly, skin biopsies did not exhibit the T-cell receptor Vbeta stimulatory properties predicted for SAg-induced skin reactions. By 6 hours after patch testing with SAg's, TNF-alpha mRNA had increased in the epidermis (but not the dermis) in biopsies from psoriatics, compared with controls. Immunohistochemical studies revealed significantly higher HLA-DR expression in keratinocytes from psoriatics than from controls. However, a mutant TSST-1 protein that fails to bind HLA-DR did not elicit an inflammatory skin reaction. These results indicate that keratinocyte expression of HLA-DR enhances inflammatory skin responses to SAg's. They may also account for previous studies failing to demonstrate selective expansion of T-cell receptor Vbetas in psoriatics colonized with SAg-producing Staphylococcus aureus, and they identify a novel T cell-independent mechanism by which SAg's contribute to the pathogenesis of inflammatory skin diseases.

Increased nitric oxide production accompanied by the up-regulation of inducible nitric oxide synthase in vascular endothelium from patients with systemic lupus erythematosus.

OBJECTIVE: To investigate whether systemic lupus erythematosus (SLE) is accompanied by increased serum nitrite levels, whether active compared with inactive disease is associated with greater nitric oxide (NO) production, and whether endothelial cells or keratinocytes serve as cellular sources of NO by virtue of their increased expression of either constitutive nitric oxide synthase (cNOS) or inducible NOS (iNOS). METHODS: Fifty-one serum samples (46 from patients with SLE) were analyzed for NO production by measuring nitrite levels in a calorimetric assay. Skin biopsy samples from 21 SLE patients and 11 healthy volunteers were evaluated immunohistochemically, using monoclonal antibodies, for endothelial cell and keratinocyte cNOS and iNOS expression. RESULTS: Serum nitrite levels were significantly elevated in the 46 patients with SLE (mean +/- SEM 37 +/- 6 microM/liter) compared with controls (15 +/- 7 microM/liter; P < 0.01), and were elevated in patients with active SLE compared with those with inactive disease (46 +/- 7 microM/liter versus 30 +/- 7 microM/liter; P < 0.01). Serum nitrite levels correlated with disease activity (r = 0.47, P = 0.04) and with levels of antibodies to double-stranded DNA (r = 0.35, P = 0.02). Endothelial cell expression of iNOS in SLE patients (mean +/- SEM score 1.5 +/- 0.2) was significantly greater compared with controls (0.6 +/- 0.2; P < 0.01), and higher in patients with active disease compared with those with inactive SLE (1.7 +/- 0.2 versus 1.2 +/- 0.2; P < 0.01). Keratinocyte expression of iNOS was also significantly elevated in SLE patients (0.9 +/- 0.1) compared with controls (0.4 +/- 0.1; P < 0.001). With regard to expression of cNOS, there were no differences between patients with active SLE, those with inactive SLE, and normal controls in either the vascular endothelium or the keratinocytes. CONCLUSION: NO production is increased in patients with SLE, and 2 potential sources of excessive NO are activated endothelial cells and keratinocytes via up-regulated iNOS.

Candida albicans induces selective expansion of human T lymphocytes expressing the T-cell receptor variable region V beta 5.1.

Candida albicans is a common pathogen which can present major problems as an opportunistic skin pathogen in patients with immunodeficiency. The exact nature of the T cell responses to C. albicans is poorly understood. The purpose of this study was to determine whether C. albicans could stimulate the selective expansion of T lymphocytes expressing particular V beta gene segments. Human T lymphocytes stimulated in vitro with an extract of C. albicans were analyzed for T cell receptor V beta gene expression by using a quantitative PCR technique. We found that stimulation of peripheral blood mononuclear cells (PBMC) produced a selective increase in the expression of V beta 5.1 and 5.2 gene transcripts. Using cytofluorographic analysis with available anti-V beta monoclonal antibodies, we verified that there was a significant selective expansion (P = 0.035) of V beta 5.1 positive T lymphocytes in PBMC from six subjects stimulated in vitro with C. albicans. PCR analysis of V beta 5.1 expansion in 10 subjects showed increases in V beta 5.1 gene transcripts in 7/10 subjects. More importantly, analysis of the T cell infiltrate 48 h after intradermal injections with C. albicans also showed significant expression of V beta 5.1 in the infiltrates, along with the infiltration of V beta 8.1 + T cells. The selective expansion of V beta 5.1 bearing T lymphocytes in PBMC stimulated with C. albicans and in skin test reactions to C. albicans suggests that a restricted population of T cells react to C. albicans. Furthermore, our present data raise the provocative possibility that one or more antigens in C. albicans can act as a superantigen, producing selective expansion of a population of T lymphocytes bearing a particular V beta specificity.

Cutaneous exposure to the superantigen staphylococcal enterotoxin B elicits a T-cell-dependent inflammatory response.

We analyzed the impact of superantigens secreted by skin-colonizing Staphylococci on the skin and the associated lymphoid tissue following epicutaneous application and intracutaneous injection of small amounts of staphylococcal enterotoxin B (SEB). A single intracutaneous injection of 50 ng of SEB elicited a strong inflammatory response in the skin of BALB/c mice. Three to 6 h later, we observed langerhans cell activation, mast cell degranulation, vasodilation, upregulation of ICAM-1, and induction of VCAM-1 on dermal blood vessels, with vascular adhesion of granulocytes. by 12 to 24 h, cell infiltration of the dermis increased, reaching the epidermis. Among the infiltrating leukocytes, a substantial number of eosinophils was found. After 48 h, the infiltrate was dominated by mononuclear cells. The response to SEB was dose-dependent, and signs of inflammation slowly disappeared over 5 to 7 days. Although the induction of VCAM-1 on dermal blood vessels suggested a role for interleukin-1/tumor necrosis factor-alpha in this reaction, the activation of monocytes/macrophages was not able to substitute for lymphocytes, as severe combined immunodeficiency (SCID) mice (which are lymphocyte-deficient) did not mount an inflammatory skin response to intradermal injection of SEB. The fact that nude mice (T-cell-deficient) also did not mount an inflammatory response to SEB indicated the T-cell dependency of the response. The V beta specificity of the SEB effect was demonstrated by the fact that SJL/J mice, which lack V beta 8+ T cells (the major SEB-reactive T cell population in mice), exhibited much weaker responses. Deletion or tolerization of SEB-reactive V beta T cells was not observed after a single intradermal injection of such minute amounts of SEB.

Evidence for superantigen involvement in cardiovascular injury due to Kawasaki syndrome.

Kawasaki syndrome (KS), the major cause of acquired heart disease in children, is an acute multisystem vasculitis frequently associated with the development of myocarditis and coronary artery abnormalities. Despite the widely held belief that KS is an infectious disease, its etiology has remained elusive. Recently, we and others have reported the selective expansion of V beta 2+ T cells in the peripheral blood of most patients in the acute, but not in the convalescent, phase of KS. These data were consistent with the concept that this illness is triggered by a bacterial superantigen. We report here that a patient who died of acute KS had selective expansion of V beta 2+ T cells in her myocardium and coronary artery. Sequence analysis of TCR beta-chain genes of V beta 2+ T cells from the myocardium showed extensive junctional region diversity. These observations, along with the demonstration of V beta 2 expansion in both the CD4+ and CD8+ T cell subsets, support the concept that the activation of infiltrating V beta 2+ T cells are involved in the cardiovascular damage associated with KS.

Evidence for a streptococcal superantigen-driven process in acute guttate psoriasis.

Recent studies have suggested that T cells play a critical role in the pathogenesis of psoriasis. Guttate psoriasis is a well-defined form of psoriasis frequently associated with streptococcal throat infection. This study tested the hypothesis that T cells in acute guttate psoriasis skin lesions may be activated by streptococcal superantigens. Peripheral blood as well as lesional and perilesional skin biopsies were analyzed for T cell receptor V beta repertoire using monoclonal antibodies against 10 different V beta families. Skin biopsies from all patients with acute guttate psoriasis, but not skin biopsies from patients with acute atopic dermatitis or inflammatory skin lesions induced in normal subjects with sodium lauryl sulfate, demonstrated selective accumulation of V beta 2+ T cells (P < 0.05). The expansion of V beta 2+ T cells occurred in both the CD4+ and the CD8+ T cell subsets. Sequence analysis of T cell receptor beta chain genes of V beta 2-expressing T cells from skin biopsies of patients with guttate psoriasis showed extensive junctional region diversity that is more compatible with a superantigen rather than a conventional (nominal) antigen-driven T cell response. All streptococcal isolates from patients with guttate psoriasis secreted streptococcal pyrogenic exotoxin C, a superantigen known to stimulate marked V beta 2+ T cell expansion. These data support the concept that acute guttate psoriasis is associated with superantigenic stimulation of T cells triggered by streptococcal superantigen(s).

Liver T cell subsets and adhesion molecules in murine graft-versus-host disease.

Murine GVHD across multiple minor histocompatibility barriers (B10.D2 into irradiated BALB/c) results in cell-mediated destruction of bile ducts inside the liver. Similar changes are characteristic of hepatic GVHD in humans following BMT. We have defined the phenotypes of inflammatory cells and the accessory/adhesion molecules expressed in the liver between day 7-14 of murine GVHD. T cells (CD3+) comprised 65% of hepatic inflammatory cells. alpha-beta and gamma-delta cells accounted for 92 and 8%, respectively of hepatic T cells. The percentage of CD4+ cells (29%) was 3 times that of CD8+ cells (11%). Lymphocyte function-associated antigen-1 (LFA-1) was expressed by the majority of inflammatory cells. Thirty per cent of the cells were positive for Mac-1, a differentiation marker of macrophages, large granular lymphocytes, and natural killer cells. Expression of intercellular adhesion molecule-1 and major histocompatibility complex class II (IAd) molecules on bile duct epithelial and portal vein endothelial cells was induced during GVHD. These results suggest that hepatic GVHD is induced by donor alpha-beta T cells through mechanisms that may involve CD4:1Ad and LFA-1:ICAM-1 interactions.

Increased ICAM-1 expression in the early stages of murine chronic graft-versus-host disease.

Chronic graft-versus-host disease (cGVHD) is considered to be a model for scleroderma, and vascular changes are considered to be important in that disease. We have examined the expression of intercellular adhesion molecule-1 (ICAM-1) and lymphocyte function associated antigen-1 (LFA-1) using monoclonal antibodies and immunohistochemistry in very early murine cGVHD. ICAM-1 is found on a number of cell types including endothelial cells. It is the natural ligand for LFA-1 found on leukocytes. Adherence of leukocytes to ICAM-1 positive cells is mediated by LFA-1 and this binding is thought to play an important role in a number of cell adhesion events in immune reactions. Experimental cGVHD across minor histocompatibility barriers is established by the iv inoculum of B10.D2 spleen cells into a sublethally irradiated BALB/c host. Ear and skin biopsies were taken at Days 0-5 and from Days 14 to 120 postinoculum. In comparison to the control group (BALB/c spleen cells given to a sublethally irradiated BALB/c host), the cGVHD mice show increased ICAM-1 expression by Day 3 on endothelial cells and mononuclear cells (MNC) and on fibroblast-like cells by Day 4. By Day 14, there are increasing numbers of ICAM-1-expressing cells and increased epidermal reactivity for ICAM-1; and finally, an increased number of LFA-1 positive infiltrating MNC. These changes wane by Day 28 and are gone by Day 120. These results support the concept that ICAM-1/LFA-1 interactions play a role in the immune regulation of cGVHD. The very early upregulation of ICAM-1 on the endothelium indicates that this cell type may be playing a primary role in cGVHD, and this model should provide a simple system in which to test regulation of endothelial activation in vivo.

Up-regulation of endothelial cell adhesion molecules characterizes disease activity in systemic lupus erythematosus. The Shwartzman phenomenon revisited.

OBJECTIVE: To test the hypothesis that during exacerbations of systemic lupus erythematosus (SLE), endothelial cells are activated to increase their expression of adhesion molecules. METHODS: Endothelial cell expression of E-selectin, vascular cell adhesion molecule 1 (VCAM-1), and intercellular adhesion molecule 1 (ICAM-1) was quantitated immunohistochemically in 20 biopsy specimens from nonlesional, non-sun-exposed skin from 16 SLE patients. Disease activity was evaluated with the SLE Disease Activity Index (SLEDAI) and with measurements of complement components C3a desArg, C3, and C4. RESULTS: The mean expression of all 3 adhesion molecules was significantly elevated in patients with SLE versus healthy controls, as well as in patients with active versus inactive SLE. The mean C3a desArg level was significantly higher in patients with active SLE compared with those with inactive SLE. The SLEDAI scores correlated directly with C3a desArg levels and inversely with C3 and with C4 levels. Evaluation of serial biopsy specimens demonstrated loss of endothelial cell adhesion molecules and reduction of C3a levels with clinical improvement. CONCLUSION: Our findings demonstrate up-regulation of the surface expression of 3 distinct adhesion molecules, E-selectin, VCAM-1, and ICAM-1, in patients with SLE. The abnormal expression of these endothelial cell adhesion molecules is most marked in patients with active disease characterized by significant elevations of the complement split product C3a desArg. We suggest that in certain SLE patients, excessive complement activation in association with primed endothelial cells induces leukocyte-endothelial cell adhesion and leuko-occlusive vasculopathy.

Una propuesta terapéutica a la sociedad de Río Gallegos (1) / A terapeutic proposal to Rio Gallegos society (1)

El trabajo intenta exponer la marginación en que se encontraba el paciente alcoholista en el seno de la sociedad familia. Ante esto surge la necesidad imperiosa de proponer un cambio de actitud hacia ellos, implementado la Atención Centrada en el Paciente y la búsqueda de normas a través de la Comunidad Terapéutica. Se ha intentado devolver la dignidad perdida al ser doliente que transcurre en un tiempo donde la sociedad no tiene como prioridad la atención de sus niños, ancianos ni pacientes psiquiátricos.

The effects of inhaled interferon gamma in normal human airways.

Recent studies suggest that cytokines such as recombinant interferon-gamma (rIFN-gamma) may play a role in the treatment of certain respiratory conditions associated with infection and inflammation. This study was designed to determine if rIFN-gamma could be delivered effectively in a group of normal human volunteers. The effectiveness of the inhaled delivery system was demonstrated by the recovery of free IFN-gamma in bronchoalveolar lavage (BAL) fluid and macrophage (M phi) expression of IP-10, an IFN-gamma-inducible molecule, after therapy but not at baseline. IL-1 beta, but not IL-8, gene transcripts also showed evidence for up-regulation after rIFN-gamma therapy. Compared with baseline, inhaled rIFN-gamma did not significantly alter clinical symptom scores, spirometry, morning peak expiratory flow rate (PEFR), or the response to methacholine. Of interest, the evening PEFR increased significantly (p = 0.02), from 568 +/- 36 L/min at baseline to 584 +/- 33 L/min after inhaled rIFN-gamma. Although there was no significant change in total white cell count in BAL fluid, the cellular composition did demonstrate a significant decrease in percentage of alveolar M phi (p = 0.02) and an increase in percentage of lymphocytes (p = 0.02) after rIFN-gamma. There were no histologic differences seen in bronchial biopsy specimens, and there was no evidence for up-regulation of ICAM-1 or HLA-DR expression after rIFN-gamma. We conclude that, in normal persons, rIFN-gamma can be effectively delivered by inhalation. Future trials using inhaled rIFN-gamma appear to be warranted for certain pulmonary diseases.

Mast cell immunohistochemistry: non-immunological immunostaining mediated by non-specific F(ab')2-mast cell secretory granule interaction.

During investigations of murine and human mast cell immunoreactivity with potential anti-interleukin-4 antibodies, non-specific, non-immunological labelling of mouse and human mast cells became apparent. Non-specific, non-immunological labelling was identified by (i) immunolabelling of mast cells when using control isotype primary antibodies, (ii) ability of conjugated secondary antibodies to label mast cells without prior mast cell exposure to a primary antibody, (iii) extinction of the non-specific labelling and retention of specific labelling when the pH of the diluting and washing buffers is shifted from pH 7.2 to pH 6.0, and (iv) reduction/extinction of the labelling when the antibodies are pre-incubated with soluble heparin prior to immunostaining. The site of the reactivity on the electron microscope level was shown to be confined to the mast cell secretory granules. The results of this study support the hypothesis that non-specific labelling of mast cells results from an ionic interaction between the F(ab')2 segments of antibodies and the heparin constituent of the mast cell secretory granules. This study points out the necessity of stringent controls when using immunohistochemistry to determine mast cell reactivity to various antibodies.