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The mechanical breaking stress and strain of cobra leather, along with their mechanical anisotropies, were studied in relation to body movement. The mechanical breaking strain in the transverse direction (TD), which was perpendicular to the direction (CCD) from the caudal to the cranial end, was much larger around the dorsum, and slightly larger around the abdomen, than that in the CCD. The mechanical strain is closely related to the expansion of skin. The mechanical anisotropy of cobra leather was relatively large in the dorsum, but smaller in the abdomen. These findings indicate that it was comparatively easy for the cobra body to expand preferentially in the TD around the dorsum and also to expand roughly equally in all directions around the abdomen, whereas expansion of the dorsum in the CCD was restricted by the spinal column. These findings also suggest that the strong mechanical anisotropy in cobra leather is closely related to the motion of the skin around the waist, which accompanies movement of the body. [ABSTRACT FROM AUTHOR]

Background: Since focal tonsillar infections are often associated with palmoplantar pustulosis (PPP), provocation tests have been performed for preoperative evaluation of tonsillectomy. However, these tests have not been fully established. Objectives: To introduce a more sensitive operative indication for tonsillectomy to the patients with PPP, we have monitored the temperature after provocation tests at palmoplantar sites, as measured by thermography, and we hypothesized that this methodology may lead to a more sensitive marker for tonsillectomy. Methods: Twenty-two PPP patients with/without clinical tonsillitis were included in this study. After mechanical tonsillar massage, using infrared thermography, we have monitored the surface temperature at palmoplantar sites of 22 patients with PPP, five chronic tonsillitis patients without PPP, and four healthy controls, to compare the findings with the skin lesional outcome after tonsillectomy. Results: There was a significant relationship between the effects of tonsillectomy and the results of provocation tests assessed by thermography. The sensitivity, specificity, and efficiency of the provocation tests with thermography of detecting a favorable outcome of tonsillectomy were 75.0, 83.3, and 77.3%, respectively, while those of the provocation tests as estimated with the conventional criteria were 37.5, 83.3, and 50.0%, respectively. Conclusion: Our results suggest that a new indicator using non-invasive thermography for the provocation tests is useful in predicting the effects of tonsillectomy for PPP. [Copyright &y& Elsevier]

IgG antibodies to a cleavage product of α-fodrin (120 kDa α-fodrin) have recently been identified as organ-specific autoantibodies in primary Sjögren’s syndrome. In this study, we examined seroreactivity of mothers and infants with neonatal lupus erythematosus (NLE) to a recombinant NH[sub 2]-terminal protein (120 kDa α-fodrin) of human α-fodrin. Serum samples were collected during the perinatal period in seven pregnancies of five mothers delivering offspring with NLE. Anti-120 kDa α-fodrin antibodies were identified by immunoblotting in six of seven perinatal maternal sera of offspring with NLE: one of two congenital heart block offspring and all five offspring with cutaneous NLE. These antibodies were placentally transmitted to infants. One of the five mothers had primary Sjögren’s syndrome, and four were asymptomatic. One asymptomatic mother did not demonstrate anti-120 kDa α-fodrin activity at the time of the first delivery of a congenital heart block infant, but was found to be positive at the time of subsequent delivery of a second child with cutaneous NLE. We propose that maternal antibodies to 120 kDa α-fodrin may be an additional serologic marker for the risk of NLE in anti-Ro/SS-A positive women. [ABSTRACT FROM AUTHOR]

SSA/Ro antigen is a soluble cellular component to which antibodies are frequently produced in patients with Sjögren's syndrome and systemic lupus erythematosus. Its exact location within the cell has yet to be determined. In this study we report the expression of SSA/Ro antigen in simian virus 40 (SV40)-transformed keratinocytes. The locations of SSA/Ro, U1RNP, and DNA antigens were studied by indirect immunofluorescence using monospecific antibodies. SSA/Ro antigen was detected in both the nucleus and cytoplasm of SV40-transformed keratinocytes tested with three monospecific sera. Primary cultured keratinocytes derived from adult human skin showed localized immunofluorescent staining within the nucleus. When Ca++ concentration of the medium was switched to 0.05 mM, these cells expressed cytoplasmic SSA/Ro antigens within 48 h. Depletion of the antibody activity with insolubilized human spleen extract abolished the staining. Surface expression of this antigen could not be detected in either primary or transformed cells. Localization of U1RNP and DNA was not altered. These results indicate that expression of SSA/Ro antigen in human keratinocytes is modulated by SV40 infection and that this antigen is expressed to a greater degree in cells that are less differentiated, transformed, or proliferating. [ABSTRACT FROM AUTHOR]

It has previously been demonstrated that susceptibility to pemphigus vulgaris is associated with human leukocyte antigen (HLA)-DR4 serologic specificity among Ashkenase Jews, and with DR4 as well as DR6 (DR14) in other ethnic groups. We genotyped HLA-DRB1, DQA1, DQB1, and DPB1 alleles in 16 patients with pemphigus by polymerase chain reaction-restriction fragment length polymorphism, to find evidence of potential HLA class II allele associations with pemphigus in Japanese patients who have a relatively homogeneous ethnic background. All nine patients with pemphigus vulgaris and five of seven patients with pemphigus foliaceus carried one or two alleles of HLA-DRB1*04 (*0403, *0406) and HLA-DRB1*14 (*1401, *1405, *1406) subtypes. Sequence analysis of these DRB1*04 and DRB1*14 alleles revealed the amino acid homology of phenylalanine at position 26 and valine at position 86 with the DRB1*0402 allele that reportedly confers a strong susceptibility to pemphigus vulgaris in Ashkenazi Jews. Thus our findings, together with previous HLA studies on pemphigus vulgaris patients of different ethnic groups, suggest that HLA-DRB1*04 and DRB1*14 alleles are commonly associated with pemphigus vulgaris across racial barriers. These HLA- DRB1 alleles are likely to be also associated with pemphigus foliaceus. Further studies on more diverse ethnic populations will be helpful in determining the significance of the association between certain amino acid residues of the class II molecules and disease susceptibility to pemphigus vulgaris as well as pemphigus foliaceus. [ABSTRACT FROM AUTHOR]

Neonatal lupus erythematosus (NLE) is an antibody-mediated disorder of infants characterized by two major clinical manifestations; cutaneous lupus lesions and congenital heart block (CHB). The disease is associated with placentally transferred maternal anti-Ro/SSA and/or La/SSB antibodies. There is a tendency for the same disease expression to occur within a sibship. To reveal a possible association of class II MHC genes with maternal anti-Ro/SSA autoimmune responses and neonatal outcomes in NLE with a relatively homogeneous ethnic background, haplotype, and allele distributions were analyzed based on the PCR-RFLP results in 26 Japanese anti-Ro/SSA-positive mothers from three groups defined by neonatal outcomes. The results were as follows: (1) maternal HLA-DR5 haplotype DRB1*1101-DQA1*0501-DQB1*0301 and individual class II alIeles making up this haplotype were significantly associated with neonatal cutaneous lupus but not CHB. Conversely, maternal HLA-DQB1*0602 carried on HLA-DR2 haplotypes was associated with CHB but not cutaneous NLE; (ii) HLA-DQA1 alleles with glutamine at position 34 of the first domain, which have reportedly been associated with the autointmune responses to Ro/SSA antigens in other ethnic groups, were increased in the mothers of infants with cutaneous involvement; and (iii) there was no particular class II HLA profile that distinguished the disease manifestations in infants. These findings suggest that specific maternal MHC class II genes might correlate with specific neonatal outcomes in NLE. [ABSTRACT FROM AUTHOR]

The expression of proliferating cell nuclear antigen (PCNA), also called cyclin, in human keratinocytes was examined by using the serum obtained from a SLE patient and a murine monoclonal antibody against PCNA/cyclin. In the normal epidermis, few of the nuclei were labeled with anti-PCNA/cyclin. This was in contrast to the positive nuclear staining seen in active lesions of psoriasis. In a primary culture of human keratinocytes growing as a monolayer, 20% - 30% of cells expressed PCNA/cyclin. SV4O-transformed human keratinocytes showed positive nuclear staining in about 40% of the cell population. In stratified keratinocytes cultured in a high Ca++ medium, PCNA/cyclin expression was decreased and only the cells in the basal and suprabasal layers showed positive staining. These results indicate that the expression of PCNA/cyclin correlates with the proliferating state in human keratinocytes and may not be associated with the mechanism of differentiation in keratinocytes. [ABSTRACT FROM AUTHOR]

Cryoproteins observed in patients with pemphigus have been shown to contain IgG, complement components, and other serum proteins. The IgG moiety possessed pemphigus antibody activity and contained kappa and lambda light chains. Cryoproteins appeared in the clinically active stage and disappeared subsequent to clinical improvement. These observations indicate that immune complexes may exist in the sera of patients with pemphigus. [ABSTRACT FROM AUTHOR]

The establishment of chamber specificity is an essential requirement for cardiac morphogenesis and function. Hesr1 (Hey1) and Hesr2 (Hey2) are specifically expressed in the atrium and ventricle, respectively, implicating these genes in chamber specification. In our current study, we show that the forced expression of Hesr1 or Hesr2 in the entire cardiac lineage of the mouse results in the reduction or loss of the atrioventricular (AV) canal. In the Hesr1-misexpressing heart, the boundaries of the AV canal are poorly defined, and the expression levels of specific markers of the AV myocardium, Bmp2 and Tbx2, are either very weak or undetectable. More potent effects were observed in Hesr2-misexpressing embryos, in which the AV canal appears to be absent entirely. These data suggest that Hesr1 and Hesr2 may prevent cells from expressing the AV canal-specific genes that lead to the precise formation of the AV boundary. Our findings suggest that Tbx2 expression might be directly suppressed by Hesr1 and Hesr2. Furthermore, we find that the expression of Hesr1 and Hesr2 is independent of Notch2 signaling. Taken together, our data demonstrate that Hesr1 and Hesr2 play crucial roles in AV boundary formation through the suppression of Tbx2. [ABSTRACT FROM AUTHOR]

Highlights: [•] All human SAA1 isoforms were unstructured at a physiological temperature. [•] No differences in the amyloidogenic properties were found among the SAA1 isoforms. [•] The fibril morphologies appeared to differ among the SAA1 isoforms. [•] The central peptides derived from SAA1 isoforms had distinct amyloidogenicities. [•] Amino acid variations of SAA may influence the pathogenesis of AA amyloidosis. [Copyright &y& Elsevier]

The monoclonal paraprotein from a typical case of scleromyxedema was isolated and characterized. The isolated paraprotein was of the IgG-lambda class, with a molecular weight of approximately 110,000 daltons compared with 160,000 daltons for normal IgG. Immunochemical studies indicated that the paraprotein was an incomplete IgG molecule which was missing a significant antigenic portion of the Fd fragment. The monoclonal paraprotein from a typical case of scleromyxedema was isolated and characterized. The isolated paraprotein was of the IgG-lambda class, with a molecular weight of approximately 110,000 daltons compared with 160,000 daltons for normal IgG. Immunochemical studies indicated that the paraprotein was an incomplete IgG molecule which was missing a significant antigenic portion of the Fd fragment. [ABSTRACT FROM AUTHOR]

The expression and properties of pemphigoid antigen of SV40-transformed human keratinocytes were studied. By indirect immunofluorescence, SV40-transformed keratinocytes in passage 80-85 expressed the pemphigoid antigen as coarsely granular perinuclear fluorescence. To characterize this antigen, NP40 extracts of cells labeled with [14C]amino acids were immunoprecipitated using sera of 8 patients: bullous pemphigoid (6 patients), chronic localized pemphigoid (1 patient), and drug-induced lichen planus pemphigoides (1 patient). These immunoprecipitates were subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis and then fluorographed. All 8 sera precipitated a protein of Mr 240K, while normal human sera did not precipitate this protein. These results indicate that SV40- transformed human keratinocytes synthesize pemphigoid antigen, and that autoantibodies in the sera of pemphigoid patients with different clinical features identify the same antigen of Mr 240K in these cells. [ABSTRACT FROM AUTHOR]

We describe a 10-year-old girl who presented with bizarre purpura. Both congenital and autoimmune hemorrhagic disorders were excluded based on her past medical history and physical and laboratory findings. Child abuse was also ruled out as purpura continued to develop after child–family separation. Histologic examination of the skin lesions revealed disruption of collagen fiber bundles. This finding indicated application of external force, leading to a definitive diagnosis of factitious purpura. Although it is very rare in school-age children, the diagnosis of factitious purpura should be included in the differential diagnosis of purpura in children. Histologic analysis of skin biopsies may aid in establishing the diagnosis. [ABSTRACT FROM AUTHOR]

Abstract: Background: Toll-like receptor (TLR) 4 is a critical receptor and signal transducer for lipopolysaccharide (LPS), a major component of Gram-negative bacteria. The MyD88-independent pathway downstream of TLR4 leads to functional dendritic cell (DC) maturation, although LPS-induced cytokine production from DCs is MyD88-dependent. Objectives: We investigated whether intracutaneously injected LPS alters the functions of cutaneous DCs, leading to enhanced contact hypersensitivity (CH). Methods: The ear swelling response was measured to evaluate the magnitude of CH. Cell proliferation of allogeneic splenocytes stimulated by DC-enriched draining lymph node (LN) cells was measured by performing a [3H]-thymidine incorporation assay. Epidermal I-A+ cells were evaluated under an epifluorescent microscope. I-A+ FITC-bearing cells from the draining LNs 24h after FITC application were analyzed on FACScan. Results: LPS augmented CH induction in C3H/HeN (HeN) and MyD88-knockout (KO) mice but not in C3H/HeJ (HeJ) and H-2Sd-bearing strains such as BALB/c mice. LPS failed to augment the allo-stimulatory ability of DCs in the draining LNs after hapten applications. LPS altered the density and morphology of epidermal I-A+ cell in HeN and BALB/c mice but not in TLR4-deficient HeJ mice. LPS increased the proportion of I-A+ FITC-bearing cells in the LNs 24h after FITC application in HeN, but not in BALB/c and HeJ. Conclusions: LPS augments the ability of DCs to migrate to the draining LNs, leading to enhanced CH via a TLR4-dependent, MyD88-independent pathway. The different effects of LPS on CH in some strains of mice may explain individual differences in the susceptibility to establish CH to daily antigen exposures in clinical settings. [Copyright &y& Elsevier]

Summary: Background: Antihistamines are widely used for the treatment of allergic diseases, such as urticaria and allergic rhinitis. They are also effective for the treatment of diseases in which T cells are mainly involved in the pathogenesis, such as atopic dermatitis (AD) and contact dermatitis. Dendritic cells (DCs) drive polarization of naive T cells into Th1 or Th2 subsets, and are also likely to be involved in AD pathogenesis. Objectives: The aim of this study was to determine the effects of antihistamines on DCs and CD4+ T cells. Methods: Human monocyte-derived DCs (MoDCs) and autologous CD4+ T cells were obtained from healthy subjects, and cultured together or independently in the presence of antihistamines. As a stimulant, we used staphylococcal enterotoxin B or the combination of anti-CD3 monoclonal antibody (mAb) and anti-CD28 mAb. The concentrations of cytokines and chemokines in culture supernatants were measured by ELISA. The expression of surface molecules on MoDCs was measured by flow cytometry. Cell proliferation in the cocultures of MoDCs and CD4+ T cells (DC-T cocultures) was measured by a [3H] thymidine incorporation assay. Results: Antihistamines inhibited the production of IFN-γ, and enhanced the production of IL-4 in DC-T cocultures. Antihistamines inhibited the production of TNF-α, TARC, MDC, IP-10, and Mig from MoDCs. Epinastine, one of antihistamines, suppressed the expression of ICAM-1 (CD54) on MoDCs. Epinastine also inhibited the proliferation of CD4+ T cells cocultured with MoDCs. Conclusions: Our findings show that antihistamines regulate immune responses by affecting the interaction between DCs and CD4+ T cells, and further DCs and CD4+ T cells independently, which may partially contribute to the control of allergic diseases such as AD and contact dermatitis. [Copyright &y& Elsevier]

Background: Connexins form the intercellular channels of the gap junction and play an integral part in a variety of biological functions, such as maintaining tissue homeostasis, cell growth control, and development. Previously it was demonstrated that the expression of connexin 26 (Cx26) can increase the metastatic potential of mouse melanoma cells. The objective of the study was to investigate the role Cx26 plays in the metastasis of human melanoma cells, focusing on the communication between melanoma cells and endothelial cells.Methods: Immunostaining was used to examine Cx26 expression in the melanoma lesions and in the endothelial cells around the melanoma cell nests. In all, 33 melanomatous tissue samples from 16 patients were studied, as well as nevocellular nevus (NCN) and normal skin samples. Cx26 mRNA and protein expression was also examined in the cultured endothelial cells. A dye-transfer assay was performed to examine gap junction formation between melanoma cells and endothelial cells.Results: Immunohistochemistry demonstrated that Cx26 was clearly expressed by the endothelial cells of the small vessels surrounding the melanoma cell nests as well as the melanoma cells. Cx26 mRNA and protein expression was detected in cultured endothelial cells. In a coculture system with human malignant melanoma cell line (HMY-1) and endothelial cells (HMVEC), immunohistochemistry indicated Cx26 expression in both types of cells and dye-transfer assay demonstrated dye-coupling from HMY-1 into HMVEC.Conclusions: Cx26 may contribute to the metastasis of melanoma by facilitating communication between melanoma cells and their surrounding endothelial cells. [ABSTRACT FROM AUTHOR]

Harlequin ichthyosis (HI) is one of the most devastating genodermatoses. Recently, ABCA12 mutations were identified as the cause of HI. A newborn Japanese male demonstrated the typical features of HI. The patient was treated with oral etretinate and his general condition has been good (now aged 1.5 years). This patient with moderate clinical severity was compound heterozygous for a novel de novo missense mutation 1160G>A (S387N) in exon 10 and a maternal deletion mutation 4158_4160delTAC (T1387del) in exon 28 of ABCA12. T1387del was a deletion of a highly conserved threonine residue within the first adenosine 5′ triphosphate-binding domain and is thought to seriously affect the function of the ABCA12 protein. Conversely, the residue 387 is located outside the known active sites of ABCA12 and S387N is predicted not to lead to a serious functional deficiency in ABCA12. Electron microscopy revealed abnormal lamellar granules in the granular layer cells and a moderate number of lipid vacuoles in the cornified cells. Disturbed glucosylceramide transport was confirmed in the cultured keratinocytes from the patient. No de novo mutation in ABCA12 has yet been reported either in HI or lamellar ichthyosis. The present case suggested that a de novo ABCA12 mutation might underlie HI.Journal of Investigative Dermatology (2006) 126, 1518–1523. doi:10.1038/sj.jid.5700295; published online 4 May 2006 [ABSTRACT FROM AUTHOR]

Severe hypersensitivity to mosquito bites (HMB) is characterized by intense local skin reactions and systemic symptoms such as high fever, lymphadenopathy, and hepatosplenomegaly. Patients with HMB often have natural killer (NK) cell lymphocytosis associated with Epstein–Barr virus (EBV) infection. Here we investigated whether mosquito bites have any influence on the oncogenesis of EBV-infected NK cells. We examined six HMB patients with EBV-infected NK cell lymphocytosis. We first demonstrated that CD4 + T cells, but not NK cells, proliferated well in response to mosquito salivary gland extracts (SGE), especially to SGE of Aedes albopictus. When NK cells were cocultured with autologous CD4+ T cells stimulated by mosquito SGE, the expression of viral oncogene latent membrane protein 1 (LMP1) was remarkably enhanced. Next, we stimulated mononuclear cells of the patients with mosquito SGE, and NK cell counts were monitored for 28 d. The counts changed little from initial levels in the culture with mosquito SGE, whereas they decreased steadily in the culture without the extracts. Furthermore, we detected LMP1 mRNA in the skin lesion induced by mosquito SGE. These results suggest that mosquito bites can induce expression of the viral oncogene LMP1 in NK cells via mosquito antigen-specific CD4 + T cells, which is involved in the oncogenesis of NK cells in vivo. [ABSTRACT FROM AUTHOR]

Ecthyma gangrenosum is a cutaneous infection associated most commonly with pseudomonal sepsis in the immunocompromised patient. We describe a previously healthy 4-year-old boy who developed ecthyma gangrenosum-like lesions secondary to antibiotic treatment for possible streptococcal infection. The skin, ears, and extremities were involved. This presentation emphasizes the importance of awareness of the rare complication of ecthyma gangrenosum-like lesions associated with non- Pseudomonas bacterial infection treated with antibiotics, even in a previously healthy child. [ABSTRACT FROM AUTHOR]

The present study was performed to generate monoclonal antibodies capable of detecting N-acetoxy-2-acetylaminofluorene (NA-AAF)-derived DNA adducts in human cells in situ. As an immunogen, we employed NA-AAF-modified single-stranded DNA coupled electrostatically to methylated protein and we produced five different monoclonal antibodies. All of them showed strong binding to NA-AAF-modified DNA, but had undetectable or minimal binding to undamaged DNA. Competitive inhibition experiments revealed that the epitope recognized by these antibodies is N-(deoxyguanosin-8-yl)-2-acetylaminofluorene (dG-C8-AAF) in DNA, although deacetylated N-(deoxyguanosin-8-yl)-2-aminofluorene in DNA is also recognized with slightly less efficiency. In contrast, these antibodies did not bind to 3-(deoxyguanosin-N2-yl)-2-acetylaminofluorene in DNA or to UV-induced lesions in DNA. Interestingly, they showed only minimal binding to small AAF–nucleoside adducts (dG-C8-AAF), indicating that DNA regions flanking a DNA-bound adduct, in addition to the adduct itself, are essential for the stable binding of the antibodies. Using an enzyme-linked immunosorbent assay with the most promising antibody (AAF-1), we detected the concentration-dependent induction of NA-AAF-modified adducts in DNA from repair deficient xeroderma pigmentosum (XP) cells treated with physiological concentrations of NA-AAF. Moreover, the assay enabled to confirm that normal human cells efficiently repaired NA-AAF-induced DNA adducts but not XP-A cells. Most importantly, the formation of NA-AAF-induced DNA adducts in individual nuclei of XP cells could be clearly visualized using indirect immunofluorescence. Thus, we succeeded in establishing novel monoclonal antibodies capable of the in situ detection of NA-AAF-induced DNA adducts in human cells. [Copyright &y& Elsevier]

Fas (APO-1/CD95) is a transmembrane protein which mediates programmed cell death (apoptosis). Cells with a mutated Fas gene are resistant to apoptosis and thus accumulate in lesional tissues. This might provide a basis for the development of neoplasias. Genomic DNA selectively obtained from Pautrier’s microabscesses in 16 cases of mycosis fungoides (MF) using a laser capture microdissection method was analyzed. Fas gene mutations were detected in 3 of 16 cases of MF (18.8%); 1 was silent and 2 were missense mutations located in exon 9. One of the 2 missense mutations involved the death domain of the Fas gene, which is essential for apoptotic signal transduction. The missense mutations resulted in the substitution of Ala with Asp at codon 220 and Ile with Thr at codon 314. Mouse T cell lymphoma cells transfected with mutant genes were resistant to apoptosis induced by the anti-Fas antibody, indicating that the missense mutations found in MF were loss-of-function mutations, thus causing the accumulation of cells in the cutaneous lesions. These findings suggest that the accumulation of lymphoid cells with Fas mutations provides, in part, a basis for the development or maintenance of MF. Copyright © 2004 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: There have been some reports on the relationship between p53 and keloid formation. However, there have been no studies comparing the p53 expression among scars in various stages of maturity. However, p63 and p73 have been identified as p53-related genes and have been found to be similar to p53 in their structures and functions and these proteins have also been suggested to relate to scar formation. Objective: We investigate the expression of three proteins of the p53 family in scars with various clinical manifestations and discuss the shared features and differences of these proteins. Methods: Forty untreated scar lesions consisting of keloids, hypertrophic scars, and atrophic scars were prepared for investigation. We detected the expression of p53, p63 and p73 proteins using Western blot analysis and histopathological study in each sample. Results: The 40 lesions were divided into four groups according to their clinical manifestations: keloid (Group A), red hypertrophic scar (Group B), white and hard hypertrophic scar (Group C), atrophic white scar (Group D). In Groups A and B, the histopathological findings demonstrated increased fibroblasts, capillary vessels and infiltration of inflammatory cells. In Group C, most of these changes decreased but proliferation of collagen fibers was evident. In Group D, the degree of proliferation of collagen fibers was much less and capillary vessels and infiltration of inflammatory cells were not evident. The levels of p53 protein elevated in Groups A, B and C and were higher in order of Groups A, B and C. In Group D, the level of p53 was almost the same as that of the control. The level of p63 protein was almost the same as that of the control in all groups. The level of p73 protein was elevated only in Group C. Conclusion: The p53 family members behave in a different manner in various scar tissues. It is suggested that these proteins play different roles in scar formation and the development of unfavorable scars. [Copyright &y& Elsevier]

Reports on a case of systemic ecthyma gangrenosum caused by pseudomonas sepsis combined with multiple perforations of the small intestine in a one-year-old boy. Characterization of ecthyma gangrenosum; Laboratory findings; Clinical evaluation under treatment.

A photosensitive form of trichothiodystrophy (TTD) results from mutations in the same XPD gene as the DNA-repair-deficient genetic disorder xeroderma pigmentosum group D (XP-D). Nevertheless, unlike XP, no increase in skin cancers appears in patients with TTD. Although the ability to repair ultraviolet (UV)-induced DNA damage has been examined to explain their cancer-free phenotype, the information accumulated to date is contradictory. In this study, we determined the repair kinetics of cyclobutane pyrimidine dimers (CPD) and (6–4)photoproducts (6–4PP) in three TTD cell strains using an enzyme-linked immunosorbent assay. We found that all three TTD cell strains are deficient in the repair of CPD and of 6–4PP. UV sensitivity correlated well with the severity of repair defects. Moreover, accumulation of repair proteins (XPB and proliferating cell nuclear antigen) at localized DNA damage sites, detected using micropore UV irradiation combined with fluorescent antibody labeling, reflected their DNA repair activity. Importantly, mutations of the XPD gene affected both the recruitment of the TFIIH complex to DNA damage sites and the TFIIH expression. Our results suggest that there is no major difference in the repair defect between TTD and XP-D and that the cancer-free phenotype in TTD is unrelated to a DNA repair defect. [ABSTRACT FROM AUTHOR]

We have recently developed a micropore ultraviolet irradiation technique. An isopore membrane filter with 3 μm diameter pores shields ultraviolet C radiation from cultured human fibroblasts, leading to partial irradiation within the cells with an average of about three exposed areas per nucleus. This study addressed the question of whether the spatial distribution of DNA damage within a cell nucleus is important in triggering ultraviolet-induced cytotoxicity. We have examined whether there are differences in cytotoxicity between partially ultraviolet-irradiated cells and uniformly irradiated cells after equal amounts of DNA damage were induced in the cell nuclei. We first determined DNA damage formation in normal human fibroblasts using an enzyme-linked immunosorbent assay. We found that 5 J per m2 ultraviolet irradiation produced an equivalent amount of cyclobutane pyrimidine dimers and (6–4) photoproducts per cell as 100 J per m2 with the membrane filter shield. At those doses, we found that both types of ultraviolet irradiation induced similar levels of cytotoxicity as assessed by a 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assay. Both types of ultraviolet-irradiated cells also had similar cell-cycle distribution and apoptosis as measured by flow cytometry. Moreover, no significant differences in repair kinetics for either type of photolesion were observed between the two different ultraviolet treatments. Similar results were obtained in Cockayne syndrome cells that are defective in transcription-coupled nucleotide excision repair. Present results indicate that in the range of photoproducts studied, the spatial distribution of DNA damage within a cell is less important than the amount of damage in triggering ultraviolet-induced cytotoxicity. [ABSTRACT FROM AUTHOR]

We have developed a novel method that uses a microfilter mask to produce ultraviolet-induced DNA lesions in localized areas of the cell nucleus. This technique allows us to visualize localized DNA repair in situ using immunologic probes. Two major types of DNA photoproducts [cyclobutane pyrimidine dimers and (6–4) photoproducts] were indeed detected in several foci per nucleus in normal human fibroblasts. They were repaired at those localized sites at different speeds, indicating that DNA photoproducts remain in relatively fixed nuclear positions during repair. A nucleotide excision repair protein, proliferating cell nuclear antigen, was recruited to the sites of DNA damage within 30 min after ultraviolet exposure. The level of proliferating cell nuclear antigen varied with DNA repair activity and diminished within 24 h. In contrast, almost no proliferating cell nuclear antigen fluorescence was observed within 3 h in xeroderma pigmentosum fibroblasts, which could not repair either type of photolesion. These results demonstrate that this technique is useful for visualizing the normal nucleotide excision repair process in vivo . Interestingly, however, in xeroderma pigmentosum cells, proliferating cell nuclear antigen appeared at ultraviolet damage sites after a delay and persisted as late as 72 h after ultraviolet exposure. This result suggests that this technique is also valuable for examining an incomplete or stalled nucleotide excision repair process caused by the lack of a single functional nucleotide excision repair protein. Thus, the technique provides a powerful approach to understanding the temporal and spatial interactions between DNA damage and damage-binding proteins in vivo . [ABSTRACT FROM AUTHOR]

Deals with a study which developed specific antibodies for the quantitation and visualization of ultraviolet-induced DNA damage. Information on the monoclonal antibodies; Technique developed for the quantitation of DNA damage; How the antibodies induce the repair kinetics of DNA damage.