ABSTRACT
Human serum amyloid A (SAA) is a precursor protein of the amyloid fibrils that are responsible for AA amyloidosis. Of the four human SAA genotypes, SAA1 is most commonly associated with AA amyloidosis. Furthermore, SAA1 has three major isoforms (SAA1.1, 1.3, and 1.5) that differ by single amino acid variations at two sites in their 104-amino acid sequences. In the present study, we examined the effect of amino acid variations in human SAA1 isoforms on the amyloidogenic properties. All SAA1 isoforms adopted α-helix structures at 4Ā°C, but were unstructured at 37Ā°C. Heparin-induced amyloid fibril formation of SAA1 was observed at 37Ā°C, as evidenced by the increased thioflavin T (ThT) fluorescence and Ć-sheet structure formation. Despite a comparable increase in ThT fluorescence, SAA1 molecules retained their α-helix structures at 4Ā°C. At both temperatures, no essential differences in ThT fluorescence and secondary structures were observed among the SAA1 isoforms. However, the fibril morphologies appeared to differ; SAA1.1 formed long and curly fibrils, whereas SAA1.3 formed thin and straight fibrils. The peptides corresponding to the central regions of the SAA1 isoforms containing amino acid variations showed distinct amyloidogenicities, reflecting their direct effects on amyloid fibril formation. These findings may provide novel insights into the influence of amino acid variations in human SAA on the pathogenesis of AA amyloidosis.
Subject(s)
Amyloidogenic Proteins/blood , Amyloidogenic Proteins/genetics , Serum Amyloid A Protein/genetics , Serum Amyloid A Protein/metabolism , Amyloidogenic Proteins/chemistry , Amyloidosis/blood , Amyloidosis/etiology , Amyloidosis/genetics , Genetic Variation , Humans , Microscopy, Electron, Transmission , Peptide Fragments/chemistry , Peptide Fragments/genetics , Peptide Fragments/metabolism , Protein Isoforms/blood , Protein Isoforms/chemistry , Protein Isoforms/genetics , Protein Multimerization , Protein Structure, Secondary , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Serum Amyloid A Protein/chemistryABSTRACT
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 [(3)H]-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-2S(d)-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.
Subject(s)
Dendritic Cells/immunology , Dermatitis, Contact/immunology , Lipopolysaccharides/immunology , Toll-Like Receptor 4/metabolism , Animals , Cells, Cultured , Chemotaxis , Dinitrofluorobenzene , Disease Models, Animal , H-2 Antigens/metabolism , Haptens , Injections, Intradermal , Langerhans Cells/immunology , Lipopolysaccharides/administration & dosage , Lymph Nodes/immunology , Lymphocyte Activation , Mice , Mice, Inbred BALB C , Mice, Inbred C3H , Mice, Inbred C57BL , Mice, Knockout , Myeloid Differentiation Factor 88/deficiency , Myeloid Differentiation Factor 88/genetics , Species Specificity , Toll-Like Receptor 4/deficiency , Toll-Like Receptor 4/genetics , Tumor Necrosis Factor-alpha/immunologyABSTRACT
BACKGROUND: Pemphigus is a rare life-threatening intractable autoimmune blistering disease caused by IgG autoantibodies to desmogleins. It has been difficult to conduct a double-blind clinical study for pemphigus partly because, in a placebo group, appropriate treatment often must be provided when the disease flares. OBJECTIVE: A multicenter, randomized, placebo-controlled, double-blind trial was conducted to investigate the therapeutic effect of a single cycle of high-dose intravenous immunoglobulin (400, 200, or 0 mg/kg/d) administered over 5 consecutive days in patients relatively resistant to systemic steroids. METHODS: We evaluated efficacy with time to escape from the protocol as a novel primary end point, and pemphigus activity score, antidesmoglein enzyme-linked immunosorbent assay scores, and safety as secondary end points. RESULTS: We enrolled 61 patients with pemphigus vulgaris or pemphigus foliaceus who did not respond to prednisolone (> or =20 mg/d). Time to escape from the protocol was significantly prolonged in the 400-mg group compared with the placebo group (P < .001), and a dose-response relationship among the 3 treatment groups was observed (P < .001). Disease activity and enzyme-linked immunosorbent assay scores were significantly lower in the 400-mg group than in the other groups (P < .05 on day 43, P < .01 on day 85). There was no significant difference in the safety end point among the 3 treatment groups. LIMITATION: Prednisolone at 20 mg/d or more may not be high enough to define steroid resistance. CONCLUSION: Intravenous immunoglobulin (400 mg/kg/d for 5 d) in a single cycle is an effective and safe treatment for patients with pemphigus who are relatively resistant to systemic steroids. Time to escape from the protocol is a useful indicator for evaluation in randomized, placebo-controlled, double-blind studies of rare and serious diseases.
Subject(s)
Immunoglobulins, Intravenous/therapeutic use , Immunologic Factors/therapeutic use , Pemphigus/drug therapy , Double-Blind Method , Female , Humans , Male , Middle Aged , Time FactorsABSTRACT
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.
Subject(s)
Factitious Disorders/complications , Factitious Disorders/pathology , Purpura/etiology , Purpura/pathology , Self-Injurious Behavior/complications , Biopsy , Child , Diagnosis, Differential , Female , Humans , Skin Diseases/etiology , Skin Diseases/pathology , Stress, Psychological/complicationsABSTRACT
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 [(3)H] thymidine incorporation assay. RESULTS: Antihistamines inhibited the production of IFN-gamma, and enhanced the production of IL-4 in DC-T cocultures. Antihistamines inhibited the production of TNF-alpha, 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.
Subject(s)
CD4-Positive T-Lymphocytes/immunology , Dendritic Cells/immunology , Enterotoxins/immunology , Histamine H1 Antagonists/pharmacology , Interferon-gamma/immunology , Interleukin-4/immunology , ADAM Proteins/antagonists & inhibitors , ADAM Proteins/biosynthesis , ADAM Proteins/immunology , Adult , Antibodies, Monoclonal/immunology , CD28 Antigens/immunology , CD28 Antigens/metabolism , CD3 Complex/immunology , CD3 Complex/metabolism , CD4-Positive T-Lymphocytes/drug effects , CD4-Positive T-Lymphocytes/metabolism , Cell Proliferation/drug effects , Chemokine CCL17/biosynthesis , Chemokine CXCL10/biosynthesis , Chemokine CXCL9/biosynthesis , Coculture Techniques , Dendritic Cells/drug effects , Dendritic Cells/metabolism , Humans , Intercellular Adhesion Molecule-1/immunology , Interferon-gamma/biosynthesis , Interleukin-4/biosynthesis , Middle Aged , Tumor Necrosis Factor-alpha/biosynthesis , Tumor Suppressor Proteins/antagonists & inhibitors , Tumor Suppressor Proteins/biosynthesis , Tumor Suppressor Proteins/immunologyABSTRACT
BACKGROUND: The relationship between herpesvirus reactivation and graft-versus-host disease (GVHD) after allogeneic stem cell transplantation (allo-SCT) is unclear. OBJECTIVE: We sought to examine the relationship between human herpesvirus (HHV) reactivation and rash/GVHD after allo-SCT by prospective evaluation. METHODS: Fifteen patients who had received allo-SCT underwent prospective serial examinations for human herpesvirus 6 (HHV-6), HHV-7, cytomegalovirus, and Epstein-Barr virus DNA in the blood by polymerase chain reaction and real-time polymerase chain reaction. Serum interferon gamma, interleukins 4 and 10, tumor necrosis factor alpha, and soluble interleukin 2 receptor (sIL-2R) were also measured. RESULTS: In 10 of 15 patients, macular/papular eruptions were seen after allo-SCT and GVHD was diagnosed. In 8 patients with rash, HHV-6 DNA levels correlated with the cutaneous manifestation. Interleukin 10 and sIL-2R also increased in association with rash. LIMITATIONS: The number of patients in our study was relatively small. Not all patients were examined for cytokines and sIL-2R. CONCLUSIONS: HHV-6 reactivation may be involved in the pathogenesis of rash/GVHD after allo-SCT.
Subject(s)
Exanthema/etiology , Graft vs Host Disease/etiology , Herpesvirus 6, Human/physiology , Interleukin-10/blood , Stem Cell Transplantation/adverse effects , Adult , Aged , DNA, Viral/blood , Female , Graft vs Host Disease/virology , Humans , Male , Middle Aged , Transplantation, Homologous , Virus ActivationABSTRACT
We describe a patient with paraneoplastic pemphigus who presented with erythrodermic lichenoid dermatitis, later developing blisters of pemphigus foliaceus type and oral erosive lesions. In addition to antibodies against the plakin family proteins, the patient's serum was positive for anti-desmoglein 1 antibodies without coexisting anti-desmoglein 3 activities by enzyme-linked immunosorbent assay, which is a very rare autoantibody profile in paraneoplastic pemphigus.
Subject(s)
Autoantibodies/blood , Mouth Mucosa/pathology , Paraneoplastic Syndromes/diagnosis , Pemphigus/diagnosis , Skin/pathology , Dermatitis, Exfoliative/etiology , Desmoglein 1/immunology , Desmoglein 3/immunology , Female , Genes, MHC Class II , Humans , Immunologic Tests , Lichenoid Eruptions/etiology , Middle Aged , Paraneoplastic Syndromes/complications , Paraneoplastic Syndromes/immunology , Pemphigus/complications , Pemphigus/immunology , Skin/immunologyABSTRACT
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.
Subject(s)
ATP-Binding Cassette Transporters/genetics , Ichthyosis, Lamellar/genetics , Mutation, Missense/genetics , Binding Sites/genetics , Cells, Cultured , Etretinate/therapeutic use , Exons/genetics , Heterozygote , Humans , Ichthyosis, Lamellar/drug therapy , Ichthyosis, Lamellar/pathology , Infant, Newborn , Keratinocytes/chemistry , Keratinocytes/pathology , Keratinocytes/ultrastructure , Keratolytic Agents/therapeutic use , Male , Severity of Illness Index , Threonine/analysisABSTRACT
Waldenstrƶm's hypergammaglobulinemic purpura (HGP) is a rare chronic disorder characterized by recurrent purpura on the legs, a polyclonal increase in serum gamma-globulin, an elevated erythrocyte sedimentation rate and a positive rheumatoid factor. A 30-year-old primigravid woman with 14 years of HGP was found to have fetal bradycardia at 25 weeks' gestation. Laboratory investigations demonstrated positive anti-Ro/SSA and anti-La/SSB antibodies in the maternal serum. Cesarean delivery was performed at 39 weeks, and a 2750-g female infant was born with complete atrioventricular block. Fortunately, the neonatal period has been uneventful without need for pace-making. Maternal HGP exacerbated just after delivery, but resolved within 1 week without treatment. Physicians should be aware of the possible presence of neonatal lupus-related anti-Ro/SSA and anti-La/SSB autoantibodies in patients with HGP. Screening for these autoantibodies is important and could be used as a marker to identify and manage high-risk pregnancies.
Subject(s)
Heart Block/congenital , Pregnancy Complications, Hematologic , Purpura, Hyperglobulinemic/complications , Adult , Female , Heart Block/embryology , Humans , Infant, Newborn , PregnancyABSTRACT
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.
Subject(s)
Aedes/immunology , CD4-Positive T-Lymphocytes/immunology , Epstein-Barr Virus Infections/complications , Hypersensitivity/complications , Insect Bites and Stings/complications , Killer Cells, Natural/virology , Lymphocytosis/etiology , Adolescent , Animals , Cell Extracts/pharmacology , Cell Proliferation , Child , Child, Preschool , Coculture Techniques , Epstein-Barr Virus Infections/immunology , Epstein-Barr Virus Infections/virology , Female , Herpesvirus 4, Human/genetics , Humans , Hypersensitivity/immunology , Infant , Insect Bites and Stings/immunology , Killer Cells, Natural/drug effects , Lymphocytosis/immunology , Lymphocytosis/virology , Male , RNA, Messenger/analysis , RNA, Messenger/metabolism , Salivary Glands/immunology , Skin/chemistry , Viral Matrix Proteins/geneticsABSTRACT
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-N(2)-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.
Subject(s)
Acetoxyacetylaminofluorene/analysis , Acetoxyacetylaminofluorene/immunology , Antibodies, Monoclonal , DNA Adducts/analysis , DNA Adducts/immunology , Animals , Cattle , Cell Line , DNA Damage , DNA Repair , Enzyme-Linked Immunosorbent Assay , Humans , Hybridomas/immunology , Mice , Microscopy, Fluorescence , Xeroderma Pigmentosum/metabolismABSTRACT
There has been tremendous interest in neonatal lupus erythematosus (NLE) since the reports of anti-Ro/SSA antibodies as a diagnostic marker. Recent studies, including ours, have revealed racial differences as well as similarities in the clinical features and immunogenetic backgrounds of Japanese and Caucasian patients with NLE. The frequency of photosensitivity and subacute cutaneous LE lesions is not high in Japanese infants with NLE, which is in sharp contrast to their Caucasian American counterparts. The majority of Japanese infants with NLE develop annular, erythematous or edematous lesions which have also been reported in association with Sjƶgren's syndrome. The frequency of isolated congenital heart block (CHB) is about 50% in Japanese anti-Ro/SSA positive neonatal lupus infants; this is similar to the frequency among Caucasians. The HLA-DR3 phenotype, which is found in the great majority of Caucasian mothers of NLE infants, is absent in Japanese mothers. Finally, both Japanese and Caucasian children with CHB are often identical to their mothers in their alleles of HLA-DRB1, DQA1 and DQB1 loci.
Subject(s)
Asian People , Heart Block/congenital , Lupus Erythematosus, Cutaneous/congenital , Lupus Erythematosus, Cutaneous/ethnology , White People , Autoantibodies/blood , Fetal Diseases/ethnology , Fetal Diseases/therapy , Heart Block/complications , Heart Block/therapy , Humans , Infant, Newborn , Japan , Lupus Erythematosus, Cutaneous/complications , Risk FactorsABSTRACT
We report two cases of bucillamine-induced bullous reactions with keratinocyte necrosis. The first patient, a 27-year-old woman, developed toxic epidermal necrolysis (TEN) over her whole body after taking bucillamine 300 mg/day for seven days. The second patient, a 63-year-old woman, developed several bullous erythemas on the mucous membranes and legs after taking bucillamine for more than two years. The fixed drug eruptions were diagnosed based on a provocation test in addition to clinical and histopathologic findings. These cases highlight the importance of considering fixed drug eruption as well as TEN in the differential diagnosis of bucillamine-induced bullous drug eruption.
Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/adverse effects , Cysteine/analogs & derivatives , Drug Eruptions/etiology , Stevens-Johnson Syndrome/etiology , Stevens-Johnson Syndrome/pathology , Adult , Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Arthritis, Rheumatoid/diagnosis , Arthritis, Rheumatoid/drug therapy , Biopsy, Needle , Cysteine/adverse effects , Cysteine/therapeutic use , Drug Eruptions/pathology , Female , Follow-Up Studies , Humans , Immunohistochemistry , Long-Term Care , Middle Aged , Risk Assessment , Severity of Illness IndexABSTRACT
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.
Subject(s)
Elapidae/physiology , Movement/physiology , Skin Physiological Phenomena , Tensile Strength , Animals , Anisotropy , In Vitro Techniques , Microscopy, Electron, Scanning , Skin/ultrastructure , Stress, MechanicalABSTRACT
We have recently developed a micropore ultraviolet irradiation technique. An isopore membrane filter with 3 microm 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.
Subject(s)
DNA Damage , Fibroblasts/radiation effects , Apoptosis/radiation effects , Cell Cycle/radiation effects , Cell Nucleus , Cells, Cultured , DNA Repair , Dose-Response Relationship, Radiation , Fibroblasts/cytology , Humans , Ultraviolet RaysABSTRACT
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.
Subject(s)
Fibroblasts/metabolism , Hair Diseases/metabolism , Hair Diseases/pathology , Pyrimidine Dimers/metabolism , DNA Helicases , DNA Repair , DNA-Binding Proteins/genetics , Fibroblasts/radiation effects , Hair Diseases/genetics , Humans , In Vitro Techniques , Microscopy, Fluorescence , Photochemistry , Severity of Illness Index , Skin/cytology , Xeroderma Pigmentosum/geneticsABSTRACT
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.
Subject(s)
DNA-Binding Proteins/metabolism , Keloid/metabolism , Nuclear Proteins/metabolism , Phosphoproteins/metabolism , Trans-Activators/metabolism , Tumor Suppressor Protein p53/metabolism , Adolescent , Adult , Atrophy , Blotting, Western , Child , Child, Preschool , Genes, Tumor Suppressor , Humans , Hypertrophy , Infant , Keloid/pathology , Middle Aged , Transcription Factors , Tumor Protein p73 , Tumor Suppressor ProteinsABSTRACT
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.
Subject(s)
Infections/diagnosis , Psoriasis/complications , Psoriasis/physiopathology , Skin Temperature , Thermography , Tonsillitis/microbiology , Adult , Female , Foot , Hand , Humans , Infections/complications , Infrared Rays , Male , Massage , Middle Aged , Palatine Tonsil , Prognosis , Sensitivity and Specificity , Tonsillectomy , Tonsillitis/surgeryABSTRACT
BACKGROUND: Natural killer (NK) cell lymphocytosis associated with Epstein-Barr virus (EBV) infection often shows severe hypersensitivity to mosquito bites (HMB) characterized by intense local skin reactions and systemic symptoms such as high fever, lymphadenopathy, and hepatosplenomegaly. However, the induction mechanism of HMB is still unclear. OBSERVATIONS: We investigated a typical case of HMB with EBV-positive NK cell lymphocytosis. CD4+ T cells dominantly infiltrated the site of the mosquito bite, while EBV-positive cells were few in comparison. CD4+ T cells, but not CD8+ T cells or NK cells, responded to the mosquito salivary gland extracts. Interestingly, coculturing of the NK cells and CD4+ T cells activated by mosquito extracts induced expression of EBV lytic-cycle proteins in the NK cells. Furthermore, the expression of BZLF1, a viral lytic-cycle transactivator, was detectable at the skin lesion induced by scratch patch testing with mosquito extract. The EBV DNA copy number levels in the plasma were elevated in systemic HMB symptoms compared with the normal condition. CONCLUSIONS: CD4+ T cells are important for the primary skin reaction to mosquito bites and might play a key role in reactivation of latent EBV infection in NK cells. This viral reactivation contributed to the pathogenesis of the infectious mononucleosis-like systemic symptoms of HMB in our present case.
Subject(s)
CD4-Positive T-Lymphocytes/immunology , Culicidae , Epstein-Barr Virus Infections , Hypersensitivity/immunology , Insect Bites and Stings/immunology , Adolescent , Animals , Computer Graphics , DNA, Viral/blood , Epstein-Barr Virus Infections/immunology , Female , Herpesvirus 4, Human/physiology , Humans , In Situ Hybridization , Insect Bites and Stings/virology , Killer Cells, Natural/immunology , Lymphocytosis/immunology , Skin Tests , Virus Activation/physiologyABSTRACT
A 47-year-old woman presented with multiple bluish subcutaneous nodules on the trunk and upper extremities. The histological diagnosis of a subcutaneous nodule was cavernous hemangioma. Multiple cavernous hemangiomas were also found in her cerebrum, cerebellum, and medulla oblongata on magnetic resonance imaging examination. We did not detect any mutations in the two loci of the TIE2 gene that have been reported in familial venous malformations.