Activated keratinocytes in the epidermis of hypertrophic scars

CD40-CD40-ligand (CD154) interactions play a critical role in immune activation. Using replication defective adenovirus encoding mouse CD154 (Ad-CD154), we modified human chronic lymphocytic leukemia B cells to express a functional ligand for CD40. This not only induces expression of immune accessory molecules on the infected cell, but also allows it to trans-activate noninfected bystander leukemia B cells. Also, factors that impair the antigen-presenting capacity of leukemia B cells are downmodulated. Ad-CD154- infected leukemia cells are highly effective stimulators in mixed lymphocyte reactions and can induce generation of cytotoxic T lymphocytes specific for autologous nonmodified leukemia cells. As such, Ad-CD154 can induce a host antileukemia response that may have therapeutic potential.     

The treatment of hypertrophic scars and keloids

We report a case of post-traumatic carotid artery dissection revealed by a painless Horner's syndrome. Horner's syndrome is a neurologic emergency when it appears rapidly, spontaneously or after a trauma. Each painful Horner's syndrome must be considered as due to a homonymous carotid artery dissection until proven otherwise. One must be attentive especially because the pain may be an inconstant finding and the Horner's syndrome incomplete. Ophthalmologists must be aware of this entity because they are the first and often only practicians to be consulted. They must consider the diagnosis, ask for an immediate MRI or angio-scan, start the treatment and assume the follow-up.     

Pulsed dye laser treatment of hypertrophic burn scars

Hypertrophic burn scars are notoriously difficult to treat because of their extensive tissue involvement and tendency to worsen with hypertrophy and contracture formation. Various therapies have been advocated in the past, including surgical excision and grafting, dermabrasion, and corticosteroids, with distinct cosmetic limitations. The 585-nm pulsed dye laser has been shown previously to be effective in the treatment of a variety of traumatic and surgical scars with improvement in scar texture, color, and pliability with minimal side effects. Sixteen patients with 40 hypertrophic burn scars resulting from chemical peels, carbon dioxide laser procedures, and accidental thermal injury were treated with a 585-nm pulsed dye laser. Sequential photographic and clinical assessments were recorded in all patients. Histologic evaluations of skin punch biopsies before and after laser irradiation were performed when possible. Symptomatic improvement of scars was reported after one treatment. Decreased scar erythema with improved texture and pliability was observed after an average of 2.5 treatments. No correlation was found between scar duration, location, or etiology and response to treatment. Normal number of dermal fibroblasts with decreased sclerosis was observed on histologic examination of laser-irradiated scars. The 585-nm pulsed dye laser irradiation of hypertrophic burn scars can effectively improve scar pliability and texture and decrease erythema and associated symptoms yielding cosmetically and functionally acceptable clinical results.     

Cytokine gene expression in human LPS- and IFNgamma-stimulated mononuclear cells is inhibited by heparin

In addition to its well-understood anticoagulant activity, heparin is known to modulate a variety of biological functions including immunologic responses. In order to investigate whether heparin influences the humoral immunity by interacting with cellular elements and affecting gene expression in blood circulating cells. we studied the effect of heparin on IL-1beta, IL-6 and TNFalpha mRNAs in human lipopolysaccharide-(LPS)- or interferon-gamma(IFN-gamma)-stimulated mononuclear cells. The study of mRNA was carried out by an initial PCR screening followed by a Northern blot quantitative analysis. Heparin (0.5 U/ml) turned out to inhibit all three cytokine gene expressions. The mRNA decrease was 37 +/- 6% for IL-1beta, 53 +/- 3% for IL-6 and 47 +/- 4% for TNFalpha with LPS stimulus. No differences could be observed in the inhibitory effect of heparin on IFNgamma-stimulated cells. This effect of heparin was confirmed in a subset of experiments performed on purified monocytes. These results suggest an important immunosuppressive effect of heparin on cell-mediated immune responses.     

Vascularization pattern in hypertrophic scars and keloids: a stereological analysis

Wound healing is a complex process that does not always occur harmoniously and may lead to pathological scar development, such as hypertrophic scars and keloids. Considering that vascularization can play a role in the development of these scars, and that the literature is controversial, we performed a stereological analysis of dermal for vessels of normal skin, normal scars, hypertrophic scars, and keloids. The parameters studied concerned vessels: surface density, length density; for vessels and myofibroblasts: volume density, in papillary and reticular dermis. The pattern of dermal vascularization in normal skin and normal scar showed no differences. In papillary demis, the number of vessels was higher in hypertrophic scars and keloids than in normal skin (p < 0.05). Vessels of hypertrophic scars were more dilated than those of normal skin (p < 0.01). In reticular dermis, vessels were present in higher amount in hypertrophic scars and keloids than in normal skin (p < 0.025; p < 0.001, respectively). The pattern of vascularization did not show any differences between hypertrophic scars and keloids. Our results show that hypertrophic scars and keloids have a distinct pattern of vascularization compared to normal skin and normal scars. This indicates that abnormal vascularization can be involved in the development of hypertrophic scars and keloids.     

Telomerase is not an epidermal stem cell marker and is downregulated by calcium

An understanding of the basic mechanisms responsible for the pathogenesis of liver neoplasms is needed in order to develop better therapeutic strategies. The present study utilized a pharmacogenetic mouse model to assess the role of cytochrome P4501A1 (Cyp1a1) in modulating genetic damage to oncogenic and tumor suppressor loci following in utero exposure to the polycyclic aromatic hydrocarbon, 3-methylcholanthrene (MC). Analysis of the Ha-ras, Ki-ras, INK4a and p53 genes was carried out with lysates from paraffin-embedded liver tissue from transplacentally-treated mice. The lysates were subjected to DNA amplification by the PCR technique followed by allele-specific oligonucleotide hybridization screening and SSCP analysis. All of the 26 neoplasms screened (23 hepatocellular carcinomas, two hepatocellular adenomas and one sarcoma) exhibited a GGC-->CGC (GLY13-->ARG13) transversion at the Ki-ras gene locus. None of the tumors had Ki-ras mutations at codon 12 of exon 1. Approximately 12% (3/26) of the liver tumors exhibited point mutations in exon 1 of the INK4a gene, with each of the three tumors exhibiting two point mutations. Analysis of exon 2 of the INK4a gene showed the presence of a CCG-->CTG (PRO73-->LEU73) transition in two of the 26 neoplasms. No mutations were found in exons 1 or 2 of the Ha-ras gene, or in exons 5-8 of the p53 gene. Analysis of tumor RNAs showed overexpression of Ha-ras, cip1 and c-jun in approximately 38% of the liver tumor samples. The results of this study suggest that mutagenic damage to oncogenes and tumor suppressor genes may be critical factors in mediating transplacentally-induced liver tumorigenesis. The fact that Ki-ras mutations were found in all of the tumors suggests that mutation at this gene locus may be an early event in liver tumor pathogenesis, while mutation in tumor suppressor genes may occur later during tumor progression. These combined results are consistent with the pathogenesis of cancer in humans.     

Laser treatment of hypertrophic scars, keloids, and striae

Lasers are now being used successfully to improve various types of scars and striae. It is not only imperative to properly categorize the type of scars and striae present, but to determine which laser or lasers can best treat them. A 585-nm flashlamp pumped pulsed dye laser is preferred for the treatment of hypertrophic scars, keloids, and striae distensae. CO2 laser vaporization of scars that are proliferative, such as hypertrophic scars and keloids, is not advised due to the high rate of recurrence or worsening. When properly used, lasers can effect the best clinical responses in hypertrophic scars and keloids ever observed. Future laser technologic advances as well as the addition of concomitant lasers or other treatments may enhance clinical results. It appears evident that by promoting the remodeling phase of wound healing, abnormal scarring may be prevented or improved. Laser surgery may best be able to accomplish this by triggering regression of blood vessels and, therefore, fibroblasts within the scar. By so doing, further deposition of connective tissue may be halted.     

Static-electric field induction by a silicone cushion for the treatment of hypertrophic and keloid scars

Silicone gel and silicone occlusive sheeting are widely used at present for the treatment of hypertrophic and keloid scars, without any scientific explanation as to their mode of action. In a recent paper the possibility was raised that static electricity generated by friction-activated silicone sheeting could be the reason for this effect, and that it can, with time, cause involution of hypertrophic and keloid scars. The objective of this study was to test this hypothesis and to observe whether a continuous and also an increased negatively charged static-electric field will shorten the treatment period. A device to implement these requirements gradually evolved over a 5-year period. A number of prototypes were tested until the final product was attained. Some of the patients in this study were treated initially with a silicone sponge inserted in the cushion. Later this version was changed to the final design described herein. A silicone cushion was developed with the purpose of increasing a negative static-electric charge to accelerate the regression process. The cushion is custom-made using a silicone occlusive sheeting envelope of 0.75-mm thickness, which does not deteriorate with use, and is partially filled with high viscosity silicone oil. Its edges are sealed, and its size is designed to extend a little beyond the scarred area. Static electricity readings, generated by activating the cushion by pumping action with the fingers, stretching or deforming the cushion, are invariably much higher when compared with those obtained with silicone occlusive sheeting and silicone gel sheeting. The interaction between the negatively charged ions of the cushion and the ionic charges of the tissue fluids may be the critical factor in achieving hypertrophic and keloid scars involution. Of the 30 patients enrolled in the study, 3 patients dropped out. Treatment with the silicone cushions yielded 63.3 percent cessation of itching and burning followed by pallor and flattening of the scar, some markedly so, over a few weeks to 6-month period. An additional 26.6 percent had their scars resolved in up to 12 months of treatment. Good contact of the cushion over the scar has been shown to be important in this clinical trial, and much creativity is needed for making elastic strap bindings that ensure this contact. The clinical trials extended over a 12-month period. Ten patients (33.3 percent) who had recalcitrant scars with little response to the use of the silicone cushion were given intralesional corticosteroid injections, in addition to the continued use of the cushion, resulting in a fairly rapid resolution of these scars over a period of months to a year.     

The usage of thermo-vac facial masks for the treatment of hypertrophic scars in children

We present the results obtained in the treatment of facial hypertrophic scars in children admitted in the Pediatric Burn Unit of the Hospital Infantil La Paz (Madrid). During the last 30 months 13 patients, with ages ranging from 3 months to 5 years, have been treated. Compared to the elastic pressure masks, rigid masks have yielded better results both on the short and the long term. Rigid masks of Thermo-Vac material turn out to be more comfortable and easier to wear and tolerate than the classical elastic appliances.     

Cytokine inducible matrix metalloproteinase expression in immortalized rat chondrocytes is independent of nitric oxide stimulation

The objective of this study was to determine if an immortalized mammalian chondrocyte cell line had a profile of matrix metalloproteinase (MMP) expression that was consistent with what has been reported for primary chondrocytes in vitro and in vivo. A combination of zymography, Western, and Northern analysis was used to examine the expression of MMPs that are relevant to cartilage degradation. Both interleukin-1beta and tumor necrosis factor alpha induced a 4- to 9-fold increase in the level of MMP-9 expression in conditioned media, and a 17- to 24-fold increase in MMP-3 mRNA. Other compounds such as basic fibroblast growth factor and staurosporine each increased MMP-9 expression individually and potentiated the effects of the two cytokines. Transforming growth factor beta had no positive or inhibitory effects. N-methyl arginine blocked the increase in nitric oxide observed following treatment with the cytokines but did not prevent the increased expression of MMPs. The pattern of metalloproteinase expression observed in IRC cells and the response to cytokines is very similar to what has been reported during the pathogenesis of osteoarthritis. The IRC cells should be useful as a model system to study basic mechanisms controlling chondrocyte MMP expression and to identify pharmacological modulators of this process.     

Topical silicone gel sheeting in the treatment of hypertrophic scars and keloids. A dermatologic experience

BACKGROUND: Topical silicone gel sheeting has been used successfully in the management of hypertrophic and keloid scars resulting from thermal burn wounds. METHODS: An open-labelled approach using the silicone gel sheets was performed using hypertrophic and keloid scars secondary to surgical procedures or traumatic insults. RESULTS: The silicone gel sheets resulted in moderate improvement in scar thickness, scar color and was noted to be effective to some degree in all tested. The material was easy to use and painless. CONCLUSION: Topical silicone gel sheeting is an effective method for the treatment of hypertrophic and keloid scars and may be considered useful in the treatment of these difficult cutaneous lesions.     

Cytokine secretion and adhesion molecule expression by granuloma T lymphocytes in Mycobacterium avium infection

Mice experimentally infected with Mycobacterium avium develop a chronic disease characterized by widespread noncaseating granulomas. In this report, we describe the phenotype and cytokine secretion profile of these granuloma-infiltrating effector T lymphocytes. In response to specific antigen, granuloma T cells and, to a lesser extent, spleen cells secrete interferon-gamma, but no interleukin-4 or -5. The importance of this Th1-like response to the host was demonstrated by the massively increased bacterial load and lethal disease in interferon-gamma knockout mice. One function of localized cytokine secretion is to recruit inflammatory T cells bearing surface adhesion molecules complementary to counter-receptors on vascular endothelial cells. Granuloma T cells express high levels of these pro-inflammatory adhesion molecules but have down-regulated their expression of L-selectin (CD62L). The expression of these adhesion molecules on granuloma-infiltrating T lymphocytes would alter the migration pathway of these cells and is likely to be important in facilitating the traffic of effector T cells to the granulomatous inflammatory site. In addition, T cells from Schistosoma mansoni granulomas express the same set of adhesion molecules, showing that this phenotype is not specifically dependent upon the Th1 pattern of cytokine secretion.     

Cytokine messenger RNA expression by donor-specific cytotoxic T-cell clones after allogeneic heart transplantation

BACKGROUND: Aspergillosis is an uncommon yet serious opportunistic infection in patients with AIDS. It has been extensively reported in HIV-infected adult patients. To our knowledge there are no studies that describe the epidemiology, clinical manifestations and outcome of aspergillosis in a large HIV-infected pediatric population. METHODS: We reviewed the records of all 473 HIV-infected children followed in the Pediatric Branch of the National Cancer Institute for 9 years from 1987 through 1995 for the presence of Aspergillus infection. RESULTS: Seven (1.5%) patients developed invasive aspergillosis during the study period. All patients had low CD4 counts reflecting severe immunosuppression. Sustained neutropenia (> 7 days) or corticosteroid therapy as a predisposing factor for invasive aspergillosis was encountered in only two patients (28%). Invasive pulmonary aspergillosis developed in five patients and cutaneous aspergillosis in two. The most common presenting features in patients with pulmonary aspergillosis were fever, cough and dyspnea. Patients with cutaneous aspergillosis were diagnosed during life and successfully treated with amphotericin B and surgery, whereas diagnosis of pulmonary aspergillosis was made clinically in only one patient. CONCLUSIONS: Aspergillosis is an uncommon but highly lethal opportunistic infection in HIV-infected children. Invasive pulmonary aspergillosis should be considered in the differential diagnosis in febrile, HIV-infected children with persistent pulmonary infiltrates.     

Cytokine expression in a rat model of Staphylococcus aureus endophthalmitis

PURPOSE: To examine the ability of viable Staphylococcus aureus to induce the production of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, cytokine-induced neutrophil chemoattractant (CINC), and interferon (IFN)-gamma after intravitreal injection. METHODS: Experimental rat eyes were injected with a 25-microl volume of approximately 80 colony-forming units of viable S. aureus; control eyes received sterile saline. Eyes were graded daily for signs of clinical inflammation and were removed 6, 24, 48, and 72 hours after injection. One group was prepared for histologic analysis, and vitreous was removed from the other group for cytokine analysis, using standard enzyme-linked immunosorbent assay procedures. RESULTS: TNF-alpha, IL-1beta, CINC, and IFN-gamma were detected in experimental vitreous samples at increased levels that peaked at 24 hours. TNF-alpha, IL-1beta, and CINC declined at 48 hours, but IFN-gamma remained elevated. At 72 hours, levels returned to baseline. Statistically significant elevations of TNF-alpha, IL-1beta, and CINC were detected in experimental samples at 24, but not at 6 and 48 hours compared with levels in saline control samples (P < 0.03). A statistically significant increase in IFN-gamma was detected at 24 and 48 hours compared with control levels (P < 0.03). In experimental animals, clinical inflammation and inflammatory cells peaked at 24 hours, persisted at 48 hours, and began to decline thereafter. Neutrophils were the predominant inflammatory cell detected at 24 (72.3% of cells) and 48 (60.1%) hours. By 72 hours, the total number of inflammatory cells had decreased by 75.0%, and the cellular infiltrate had changed so that neutrophils equaled monocytes-macrophages. CONCLUSIONS: S. aureus induced the expression of TNF-alpha, IL-1beta, CINC, and IFN-gamma. The time course of these cytokine levels could account for the clinical inflammatory responses and the entry and decline of vitreous cells in this model of bacterial endophthalmitis.