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1.
Clin Case Rep ; 11(6): e7532, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37305885

RESUMO

Key Clinical message: A patient with eosinophilic granulomatosis with polyangiitis, who was well-controlled by pharmacotherapy, developed a psoriasis-like rash due to a local infection. It represents the consequence of an immunologic imbalance. Abstract: A 48-year-old woman was diagnosed with eosinophilic granulomatosis with polyangiitis and treated with mepolizumab. While on treatment, she developed a psoriasis-like rash on her lower legs following a local ear infection. The rash promptly disappeared after the ear infection cleared and did not recur. The psoriasis-like rash that appeared was pathologically similar to psoriasis. Excessive production of inflammatory cytokines by the immune system is believed to be involved in the pathogenesis of psoriasis vulgaris. These cytokines are known to induce inflammatory responses and promote epidermal cell proliferation. It is possible that mepolizumab treatment suppressed Th2-type cytokines, while the local ear infection temporarily induced a strong Th1-type immunity. This immunologic imbalance may have led to the development of a psoriasis-like rash.

4.
Clin Pract ; 13(2): 367-371, 2023 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-36961058

RESUMO

A 91-year-old woman visited our department with scattered small nodule lesions and multiple pules or plaques with a stuck-on appearance. The lesions were intractable and resistant to several treatments. Immunodeficiency was excluded by examinations including a CT scan, white blood cell (WBC) counts, natural killer and neutrophil function assays, and IgG titers against human papillomavirus (HPV) 20. HPV20 was identified using the PCR method. The finding of the skin biopsy showed an irritated type of feature of seborrheic keratosis. Additionally, immunohistochemical staining of the lesion revealed that both TNF-α and IFN-ɤ were produced at the skin lesions. The patient's serum zinc level was slightly low. We noticed that zinc deficiency has been reported to decrease the cytotoxic activity of natural killer cells, which play an important role in eliminating virus-infected cells and tumor cells. Finally, zinc oxide ointment was found to improve the lesions dramatically. HPV20 causes tumors only in immunodeficient patients or in patients with epidermodysplasia verruciformis (EV). In EV, EVER1- or EVER2-encoding membrane proteins, of which are related to zinc transport protein-1 expressed on the membrane of the endoplasmic reticulum, were mutated, leading to increased susceptibility to various viral and bacterial infections due to the decreased intracellular zinc concentration. We speculated that the reduction in local zinc concentration was ameliorated by using zinc oxide ointment, resulting in the recovery from HPV20 infection.

5.
Dermatopathology (Basel) ; 9(3): 287-291, 2022 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-35997351

RESUMO

A 76-year-old Japanese man presented with a 6-year history of a sore throat. He was treated at several clinics without any improvement before being referred to us. Physical examination revealed widespread erosions and ulcers from the palate to the larynx. Approximately 25 × 15 mm in size, erosive lesions were present on the retroauricular regions, forearms, and glans penis. Pseudomembranous conjunctivitis was also observed. The skin biopsy revealed a partial cleft formation below the epidermis, suggesting subepidermal bullous disease. Immuno-serological tests were negative for anti-desmoglein 1 (Dsg1), anti-Dsg3, anti-BP180, and anti-BP230 antibodies by ELISAs. A whole-body examination revealed gastric cancer. The possibility of mucous membrane pemphigoid (MMP) or paraneoplastic pemphigus (PNP) was considered. Indirect immunofluorescence using rat bladders showed positive IgG reactivity with cell surfaces on the transitional epithelia. Immunoblotting using recombinant proteins of laminin-332 showed both IgG and IgA reactivities with laminin-α3, and immunoblotting using normal human epidermal extract showed double-positive reactivities with envoplakin and periplakin for both IgG and IgA antibodies. Based on the clinical and histopathological features and results of various immuno-serological tests, our case was diagnosed as anti-laminin-332-type MMP with serological findings of PNP. Twenty days after laparoscopic gastrectomy, treatment with oral methylprednisolone 32 mg/day was initiated, and mucosal and skin lesions improved.

6.
Int J Mol Sci ; 23(10)2022 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-35628531

RESUMO

Systemic amyloidosis is recognized as a serious complication of rheumatoid arthritis or inflammatory bowel disease, but also of inflammatory skin disease. However, the detailed molecular mechanism of amyloidosis associated with cutaneous inflammation remains unclear, and therapeutic approaches are limited. Here, we investigated the pathophysiology of amyloidosis secondary to cutaneous inflammation and the therapeutic effects of Janus kinase (JAK) inhibitors by examining a mouse model of spontaneous dermatitis (KCASP1Tg mice). Moreover, KCASP1Tg mice were crossed with interleukin-17A (IL-17A) knockout mice to generate IL-17A-/KCASP1Tg and examine the role of IL-17A in amyloidosis under cutaneous inflammation. KCASP1Tg mice showed severe amyloid deposition in the liver and spleen. Increased serum-neutral fat levels and decreased lymphocyte production were observed in the spleen. Overproduction of amyloidosis was partially ameliorated by the administration of JAK inhibitors and was further improved in IL-17A-/KCASP1Tg mice. IL-17A-producing cells included CD4, gamma delta, and CD8 T cells. In summary, our results from the analysis of a mouse model of dermatitis revealed that skin-derived inflammatory cytokines can induce amyloid deposition in the liver and spleen, and that the administration of JAK inhibitors and, even more, IL-17A ablation, reduced amyloidosis. This study demonstrates that active control of skin inflammation is essential to prevent internal organ amyloidosis.


Assuntos
Amiloidose , Dermatite Atópica , Interleucina-17 , Inibidores de Janus Quinases , Dermatopatias , Animais , Citocinas , Modelos Animais de Doenças , Inflamação , Interleucina-17/genética , Inibidores de Janus Quinases/farmacologia , Fígado , Camundongos , Baço
7.
Dermatopathology (Basel) ; 9(2): 94-99, 2022 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-35466241

RESUMO

Eccrine angiomatous hamartoma (EAH) is a relatively rare benign skin disease characterized by the proliferation of eccrine sweat glands associated with capillary hemangioma and the proliferation of other skin elements such as adipose tissue, hair, and epidermis. The onset of the disease is usually at birth or in childhood and tends to occur in the extremities of females, but it occurred in an adult male in this case. The patient was a 72-year-old man with a 12 × 12 mm light brown, elastic, slightly firm skin nodule on the flexor aspect of his right forearm. A biopsy revealed enlargement of blood vessels, sweat glands, sweat ducts, and erector spongiosum with both lumen dilation and narrowing, leading to the diagnosis of EAH. The histopathological features of EAH include a marked proliferation of microvessels, epithelial-like changes in vascular endothelial cells (such as enlarged nuclei), and infiltration of inflammatory cells, mainly lymphocytes and plasma cells. In adult-onset cases, EAH can be clinically difficult to distinguish from epithelioid hemangioma (EH), which differs in the predominance of microvascular proliferation and the presence of eosinophils in the infiltrating inflammatory cells. It can also be distinguished from EAH by the negative results of S100 and anti-EMA in immunohistological staining. In the current cases, we were able to differentiate the two cases from characteristic findings on HE staining.

8.
Int J Rheum Dis ; 25(3): 364-366, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35023307

RESUMO

We report a case of eosinophilic fasciitis triggered by strenuous physical activity, which did not relapse during the follow-up period. We ascertained that interleukin-33 (IL-33) was released from the vascular endothelial cells after intense exercise, inducing type 2 innate lymphocytes (ILC2) and causing fasciitis. A healthy woman experienced itching on both limbs a few hours after a game of drumming. Her hand, knee joints, and legs gradually swelled up with groove signs along the superficial veins. White blood cell and eosinophil counts were significantly elevated. Magnetic resonance imaging revealed a high signal at the fascia on both lower limbs. Histopathological findings of the left lower limb tissue specimen showed edematous fascia with eosinophils. No relapse of eosinophilic fasciitis was observed after finishing treatment with prednisolone. Immunological staining for IL-4, IL-5, IL-33, tumor necrosis factor-α, and interferon-γ was performed on the fascial tissue. Both IL-4 and IL-5 were stained on the lymphocytes at the muscle and fascia levels; however, CD3 and CD4 were unstained in these cells, suggesting that those cells were ILC2. Tumor necrosis factor-α and interferon-γ were unstained. Vascular endothelial cells in the fascia strongly expressed IL-33. Eosinophilic fasciitis may be associated with type 2 immunity triggered by IL-33 in the current case.


Assuntos
Eosinofilia/imunologia , Fasciite/imunologia , Imunidade Inata , Linfócitos/patologia , Biópsia , Diagnóstico Diferencial , Eosinofilia/patologia , Fasciite/patologia , Feminino , Humanos , Contagem de Leucócitos , Linfócitos/imunologia , Imageamento por Ressonância Magnética/métodos , Músculo Esquelético/patologia , Adulto Jovem
9.
Case Rep Dermatol ; 13(1): 238-243, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34054459

RESUMO

Here, we report two cases of cutaneous adverse effects possibly induced by the use of tumor necrosis factor-alpha (TNF-α) inhibitors. The first case presented alopecia areata (AA) and atopic dermatitis (AD) that developed during the treatment of ulcerative colitis using infliximab; the other case presented urticaria and AD that developed during the treatment of rheumatoid arthritis using etanercept. AA, AD, and urticaria are relatively common skin diseases; however, they are not well known as adverse effects of TNF-α inhibitors. Although immunological studies were not performed, the clinical courses suggested that these skin disorders might have developed as a result of an immune four-way imbalance in T helper 1 (Th1), Th2, Th17, and regulatory T cells by the administration of TNF-α inhibitors.

11.
Int J Mol Sci ; 23(1)2021 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-35008464

RESUMO

Malnutrition is not only regarded as a complication of rheumatoid arthritis and inflammatory bowel disease but also that of inflammatory skin disease; however, the mechanisms and efficacy of its treatment have not been elucidated. Using a mouse model of dermatitis, we investigated the pathophysiology of malnutrition in inflammatory skin conditions and efficacy of its treatment. We employed spontaneous skin inflammation mice models overexpressing human caspase-1 in the epidermal keratinocytes. Body weight, nutrition level, and α1-antitrypsin fecal concentration were measured. The gastrointestinal tract was histologically and functionally investigated. Fluorescein isothiocyanate (FITC)-dextran was forcibly fed on an empty stomach, and plasma FITC-dextran was measured. The treatment efficacy of antibodies against tumor necrosis factor-α (TNF-α) and interleukin (IL)-α/ß as well as Janus kinase (JAK) inhibitors was investigated. Compared with wild-type littermates, the inflammatory skin mice models showed a lowered body weight, reduction of serum albumin level, amyloid deposition in the stomach, small intestine, and large intestine, and increased α1-antitrypsin fecal concentration. However, the plasma FITC-dextran was unchanged between the dermatitis models and wild-type littermates. The over-produced serum amyloid A1 in the liver was detected in the plasma in the dermatitis model. Antibodies against TNF-α and IL-α/ß showed partial effects on amyloid deposition; however, JAK inhibitors improved gastrointestinal amyloidosis with the improvement of skin symptoms. Chronic dermatitis is closely related to secondary amyloidosis in the gastrointestinal tract, resulting in hypoalbuminemia. Therefore, active control of skin inflammation is essential for preventing gastrointestinal complications.


Assuntos
Amiloidose/tratamento farmacológico , Dermatite/tratamento farmacológico , Trato Gastrointestinal/efeitos dos fármacos , Hipoalbuminemia/tratamento farmacológico , Inibidores de Janus Quinases/farmacologia , Amiloidose/metabolismo , Animais , Citocinas/metabolismo , Dermatite/metabolismo , Modelos Animais de Doenças , Feminino , Trato Gastrointestinal/metabolismo , Hipoalbuminemia/metabolismo , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Pele/efeitos dos fármacos , Pele/metabolismo
12.
Case Rep Dermatol Med ; 2020: 6682694, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33343946

RESUMO

Verruca vulgaris is an infectious disease caused by the human papillomavirus and characterized by hyperkeratotic papules or plaques with a clear boundary. Seborrheic keratosis is a commonly encountered lesion on the face, trunk, or extremities and is described as seborrheic verruca because of its clinical similarity to warts; furthermore, it is occasionally associated with immune suppression, especially in cases of Leser-trélat syndrome. Although these diseases are frequently found in healthy individuals, they typically show a good response to cryotherapy. However, cases in immunosuppressed patients are intractable to therapy. Overall immune status is evaluated via complete blood count (CBC); however, white blood count does not show the exact immune ability, and NK cell activity is often decreased in cases of malignancy. Here, we present two cases of exacerbated verruca vulgaris and seborrheic verruca observed in patients with malignancy. Although the patients seemed to be in good condition and had a normal CBC, immunosuppression was suspected based on the degree of skin rashes. NK cell activity was decreased in both patients, and both cases had malignancy. The measurement of NK cell activity may be a useful approach to evaluate immune status.

13.
Dermatopathology (Basel) ; 7(2): 41-47, 2020 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-32937752

RESUMO

Inherited epidermolysis bullosa (EB) is a rare genetic skin disorder characterized by epithelial tissue fragility. Recessive dystrophic epidermolysis bullosa (RDEB) is the most severe form, characterized by the presence of blisters, erosion, and ulcer formation, leading to scarring and contraction of the limbs. RDEB is also associated with extra-cutaneous complications, including emaciation, congestive heart failure, and systemic amyloidosis. The main cause of these clinical complications is unknown; however, we hypothesized that they are caused by elevated circulating inflammatory cytokines overproduced by injured keratinocytes. We addressed this phenomenon using keratin-14 driven, caspase-1 overexpressing, transgenic (KCASP1Tg) mice in which injured keratinocytes release high levels of IL-1α and ß. KCASP1Tg showed severe spontaneous dermatitis, as well as systemic complications, including aberrant weight loss, cardiovascular disease, and extensive amyloid deposition with organ dysfunction, resembling the complications observed in severe EB. These morbid conditions were partially ameliorated by simultaneous administration of anti-IL-1α and ß antibodies. The skin not only constitutes a physical barrier, but also functions as the largest immune organ. We suggest a novel role for IL-1 in the pathogenesis of EB and the use of anti-IL-1 antibodies as a potential therapy for EB complications.

14.
Int J Mol Sci ; 21(9)2020 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-32397568

RESUMO

: Adipose tissue (AT) is the largest endocrine organ, producing bioactive products called adipocytokines, which regulate several metabolic pathways, especially in inflammatory conditions. On the other hand, there is evidence that chronic inflammatory skin disease is closely associated with vascular sclerotic changes, cardiomegaly, and severe systemic amyloidosis in multiple organs. In psoriasis, a common chronic intractable inflammatory skin disease, several studies have shown that adipokine levels are associated with disease severity. Chronic skin disease is also associated with metabolic syndrome, including abnormal tissue remodeling; however, the mechanism is still unclear. We addressed this problem using keratin 14-specific caspase-1 overexpressing transgenic (KCASP1Tg) mice with severe erosive dermatitis from 8 weeks of age, followed by re-epithelization. The whole body and gonadal white AT (GWAT) weights were decreased. Each adipocyte was large in number, small in size and irregularly shaped; abundant inflammatory cells, including activated CD4+ or CD8+ T cells and toll-like receptor 4/CD11b-positive activated monocytes, infiltrated into the GWAT. We assumed that inflammatory cytokine production in skin lesions was the key factor for this lymphocyte/monocyte activation and AT dysregulation. We tested our hypothesis that the AT in a mouse dermatitis model shows an impaired thermogenesis ability due to systemic inflammation. After exposure to 4 °C, the mRNA expression of the thermogenic gene uncoupling protein 1 in adipocytes was elevated; however, the body temperature of the KCASP1Tg mice decreased rapidly, revealing an impaired thermogenesis ability of the AT due to atrophy. Tumor necrosis factor (TNF)-α, IL-1ß and interferon (INF)-γ levels were significantly increased in KCASP1Tg mouse ear skin lesions. To investigate the direct effects of these cytokines, BL/6 wild mice were administered intraperitoneal TNF-α, IL-1ß and INF-γ injections, which resulted in small adipocytes with abundant stromal cell infiltration, suggesting those cytokines have a synergistic effect on adipocytes. The systemic dermatitis model mice showed atrophy of AT and increased stromal cells. These findings were reproducible by the intraperitoneal administration of inflammatory cytokines whose production was increased in inflamed skin lesions.


Assuntos
Citocinas/fisiologia , Dermatite/patologia , Gordura Intra-Abdominal/patologia , Células Estromais/efeitos dos fármacos , Adipócitos/patologia , Adipocinas/biossíntese , Adipocinas/genética , Tecido Adiposo Branco/patologia , Animais , Atrofia , Caspase 1/fisiologia , Tamanho Celular , Temperatura Baixa , Citocinas/biossíntese , Citocinas/toxicidade , Dermatite/imunologia , Dermatite/metabolismo , Modelos Animais de Doenças , Feminino , Inflamação , Gordura Intra-Abdominal/imunologia , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Monócitos/imunologia , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Proteínas Recombinantes/toxicidade , Células Estromais/metabolismo , Subpopulações de Linfócitos T/imunologia , Proteína Desacopladora 1/biossíntese , Proteína Desacopladora 1/genética
15.
Int J Mol Sci ; 21(9)2020 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-32392785

RESUMO

Psoriasis is one of the common chronic inflammatory skin diseases in which inflammatory cytokines such as IL-17 and TNF-α play critical roles. Skin microbiome of psoriasis patients is reported to have elevated Staphylococcus and Streptococcus genus. There are controversial reports about gut microbiome of psoriasis patients, and whether the diversity of bacteria in genus level is decreased or not is still unclear. Moreover, it is not yet known if these gut bacteria would be the cause of the inflammation or the result of the inflammation. We analyzed the gut microbiome of the inflammatory skin model mouse (keratinocyte-specific caspase-1 transgenic (Kcasp1Tg) mouse), by analyzing the 16S rRNA gene. Staphylocuccus aureus and Streptococcus danieliae were abundant in Kcasp1Tg mouse fecal microbiome. These dominant bacteria as well as recessive control bacteria were orally administrated to antibiotic-treated wild type mice, and set up imiquimod-induced psoriasis-like skin inflammation model. The skin inflammation including ear thickness and histopathological findings was analyzed. The exacerbated skin lesions with the elevated levels of TNF-α, IL-17A, IL-17F, and IL-22 were observed in Staphylocuccus aureus and Streptococcus danieliae administrated groups. Our finding suggests that there is affinity between skin inflammation severity and certain gut bacteria leading to a vicious cycle: skin inflammation populates certain gut bacteria which itself worsens the skin inflammation. This is the first report on Staphylocuccus aureus and Streptococcuus danieliae effects in vivo. Not only treating the skin lesion but also treating the gut microbiome could be the future key treatment for inflammatory skin disease such as psoriasis.


Assuntos
Citocinas/genética , Imiquimode/efeitos adversos , Psoríase/microbiologia , Staphylococcus aureus/isolamento & purificação , Streptococcus/isolamento & purificação , Administração Oral , Animais , Animais Geneticamente Modificados , Modelos Animais de Doenças , Fezes/citologia , Feminino , Microbioma Gastrointestinal , Humanos , Interleucina-17/genética , Interleucinas/genética , Camundongos , Psoríase/induzido quimicamente , Psoríase/genética , Psoríase/imunologia , RNA Ribossômico 16S/genética , Staphylococcus aureus/genética , Staphylococcus aureus/imunologia , Streptococcus/genética , Streptococcus/imunologia , Fator de Necrose Tumoral alfa/genética , Regulação para Cima , Interleucina 22
18.
Case Rep Dermatol ; 11(3): 317-321, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31911769

RESUMO

We present a case of psoriasiform dermatitis developing during the treatment of juvenile idiopathic arthritis with tocilizumab (TCZ). The keratotic erythema with central healing showed a periodicity of growing worse 1 week after TCZ infusion, and then disappeared within 3 weeks. Skin biopsy showed parakeratosis, microabscess, rete ridge elongation, and abundant lymphocytes as well as a few neutrophil infiltrate in the upper dermis. TCZ is a humanized monoclonal antibody against interleukin 6 (IL-6) receptor. IL-6 plays a critical role in the differentiation from naïve T cells into Th17 cells in cooperation with transforming growth factor-ß. IL-6 may be important in psoriasis pathogenesis, and therefore this phenomenon may be the adverse effect. The mechanism of TCZ-associated psoriasiform dermatitis is unclear. The serum IL-6 level seems to be elevated transitorily after TCZ administration, probably due to the competitive inhibition of IL-6 receptor alpha to IL-6. Excess free IL-6 may effect on other IL-6 family receptors. Since TCZ does not alter serum IL-17F level, another cytokine may be involved in the psoriasis formation in our case. Psoriasiform dermatitis during the use of TCZ may be due to relative cytokine balance disturbance.

19.
J Virol ; 87(15): 8342-50, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23698295

RESUMO

For most parainfluenza viruses, a virus type-specific interaction between the hemagglutinin-neuraminidase (HN) and fusion (F) proteins is a prerequisite for mediating virus-cell fusion and cell-cell fusion. The molecular basis of this functional interaction is still obscure partly because it is unknown which region of the F protein is responsible for the physical interaction with the HN protein. Our previous cell-cell fusion assay using the chimeric F proteins of parainfluenza virus 5 (PIV5) and simian virus 41 (SV41) indicated that replacement of two domains in the head region of the PIV5 F protein with the SV41 F counterparts bestowed on the PIV5 F protein the ability to induce cell-cell fusion on coexpression with the SV41 HN protein while retaining its ability to induce fusion with the PIV5 HN protein. In the study presented here, we furthered the chimeric analysis of the F proteins of PIV5 and SV41, finding that the PIV5 F protein could be converted to an SV41 HN-specific chimeric F protein by replacing five domains in the head region with the SV41 F counterparts. The five SV41 F-protein-derived domains of this chimera were then divided into 16 segments; 9 out of 16 proved to be not involved in determining its specificity for the SV41 HN protein. Finally, mutational analyses of a chimeric F protein, which harbored seven SV41 F-protein-derived segments, revealed that replacement of at most 21 amino acids of the PIV5 F protein with the SV41 F-protein counterparts was enough to convert its HN protein specificity.


Assuntos
Proteína HN/metabolismo , Rubulavirus/fisiologia , Proteínas Virais de Fusão/metabolismo , Internalização do Vírus , Sequência de Aminoácidos , Animais , Fusão Celular , Linhagem Celular , Cricetinae , Análise Mutacional de DNA , Proteína HN/genética , Humanos , Dados de Sequência Molecular , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Recombinação Genética , Rubulavirus/genética , Proteínas Virais de Fusão/genética
20.
Anal Sci ; 18(3): 277-81, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11918185

RESUMO

Polypropyleneglycol acrylate (PGA), one of the typical acrylic oligomers manufactured industrially, was comprehensively characterized by gas chromatography (GC), supercritical fluid chromatography (SFC) and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS). The homologous series of polypropyleneglycol diacrylate (DA), polypropyleneglycol monoacrylate (MA), and unreacted polypropyleneglycol (PG) were observed as Na adducts in the MALDI-MS spectra of the PGA samples. The relative intensities of these peaks reflect the distributions of the homologues, although their accurate quantification was generally difficult because of change in the ionization efficiency depending on the chemical structure and the molecular weight of the species. On the other hand, the DA and the MA homologues were observed in the chromatograms obtained by SFC in a temperature-programming mode, while the PG homologues were not detected under the given SFC conditions using UV detection. Here, the determination of the degree of polymerization of each component in the chromatograms was accomplished through SFC fractionation for the corresponding peaks, followed again by MALDI-TOF-MS measurement. Furthermore, most of the components in the PGA samples were almost completely separated in the resulting gas chromatograms, and their unequivocal assignments were made also using the retention data on the gas chromatograms of the SFC fractions. As for the quantitative analysis, the relative abundances among DA, MA and PG for lower degrees of polymerization can be easily calculated based on the observed gas chromatograms, whereas the distribution of DA and MA can be estimated from the observed SFC data even for the relatively higher molecular weight fractions, which are generally difficult to determine accurately by GC because of their lower volatility. These results demonstrated that even the complex PGA samples were able to be characterized in detail by using GC, SFC and MALDI-TOF-MS complementarily.

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