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Background: The activation of innate immunity may be involved in the development of Candida albicans-induced murine vasculitis, which resembles Kawasaki disease (KD) vasculitis. This study aimed to histologically clarify the time course of the development of vasculitis in this model in detail and to estimate the potential role of spleen tyrosine kinase (Syk) inhibitors in KD vasculitis., Methods and Results: DBA/2 male mice were intraperitoneally injected with a vasculitis-inducing substance and treated with a Syk inhibitor (R788 or GS-9973). Systemic vasculitis, especially in the aortic annulus area, was histologically evaluated. Regarding lesions in the aortic annulus area, some mice in the untreated control group already showed initiation of vasculitis 1 day after the final injection of a vasculitis-inducing substance. The vasculitis expanded over time. Inflammation occurred more frequently at the aortic root than at the coronary artery. The distribution of inflammatory cells was limited to the intima, intima plus adventitia, or all layers. In the Syk inhibitor-treated groups, only one mouse had vasculitis at all observation periods. The severity and area of the vasculitis were reduced by both Syk inhibitors., Conclusion: Candida albicans-induced murine vasculitis may occur within 1 day after the injection of a vasculitis-inducing substance. Additionally, Syk inhibitors suppress murine vasculitis., Competing Interests: Declaration of competing interest None., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Objective: The objective of the study was to analyse the trends in Takayasu arteritis (TAK) in Japan during three recent decades based on autopsy reports., Methods: We extracted TAK cases from the Japanese Pathological Autopsy Reports published during three decades (1991-2000, 2001-10, and 2011-20) and compared the data for the number of cases, age, gender, malignant tumour complication rate, and cause of death., Results: 322 TAK cases were reported during the 30 years. They represented 0.04-0.06% of the total autopsies, with little variation among the three decades. The peak age at autopsy increased: from the 60s for 1991-2010 to the 70s for 2011-20. The malignant tumour complication rate increased to 12.2%, 18.5%, and 22.7% during the three decades. However, about half of those cases had no metastases, and malignant tumours were rarely directly involved in a TAK patient's death. TAK-associated cardiovascular lesions accounted for most deaths., Conclusions: Although the age at TAK onset showed little change during the 30 years, the age at autopsy has increased, suggesting that the long-term prognosis has improved. Although the malignant tumour complication rate increased with age, the most common causes of death were cardiovascular lesions., (© Japan College of Rheumatology 2024. Published by Oxford University Press.)

We conducted an autopsy on a 3-month-old boy in whom Kawasaki disease (KD) was strongly suspected based on the autopsy findings. The infant had a fever and was brought to a nearby clinic, where he was prescribed antipyretics and kept under observation. However, 15 days after onset of the fever, he suddenly died in bed. He exhibited no obvious redness of the lips, tongue, or conjunctiva. Membranous desquamation was present on his distal fingers. Vasculitis was observed in the coronary arteries, renal artery, splenic artery, and pulmonary vein. In addition, coronary artery aneurysms were present in the right coronary artery and left anterior descending artery. Thrombotic occlusion was observed in one aneurysm in the right coronary artery, resulting in acute myocardial infarction. The coronary artery wall showed infiltration of numerous macrophages and neutrophils. This case was classified as incomplete KD because the coronary artery aneurysm could not be demonstrated before death and was only recognized at autopsy. Pathologists and forensic scientists need to be aware that there are cases in which KD goes undiagnosed and untreated, leading to coronary artery aneurysm formation and sudden death., (© 2024 Japanese Society of Pathology and John Wiley & Sons Australia, Ltd.)

Background: Calcification of coronary artery aneurysms (CAAs) is common in the remote phase of Kawasaki disease (KD), but the detailed features of its development remain unclear. This study aimed to elucidate the histological characteristics of calcification in KD CAAs., Materials and Methods: The study materials consisted of 24 coronary artery branches with aneurysms that were obtained from 14 Japanese patients who died during the period from 40 days to 3 years after the onset of KD. We first examined the CAAs for the presence of thrombi and calcification. When calcifications were observed, we determined their location and shape, and investigated the time-course of the changes based on the time-interval from KD onset until death. Then we measured the area of each calcification and examined for correlations between the calcified area, and (1) the disease duration, and (2) the aneurysm diameter., Results: Calcification was observed in 14 of 24 CAAs (in 7 of 13 LCA and 7 of 11 RCA). Thrombi were also seen in 13 of 14 CAAs with calcification. Calcification showed two localizations: in the organized portion of the thrombus (seen in 12 CAAs) and deep in the thickened tunica of the intima (3 CAAs). The earliest observation of calcification was in an infant who died on the 49th disease day: it was a small, band-shaped calcified lesion in granulation tissue that had formed at the boundary between the thrombus and the blood vessel wall. As the duration of KD increased, the calcified lesion increased in size, and nodular shapes were formed. Moreover, the calcified area tended to increase as the diameter of the aneurysm increased., Conclusion: Histologically, CAA calcification starts early in the remote phase of KD, and it is closely related to organization of thrombi., (Copyright © 2022. Published by Elsevier Inc.)

A 73-year-old woman was hospitalized with sudden chest pain and hematemesis. Chest computed tomography and upper gastrointestinal endoscopy revealed an idiopathic submucosal hematoma from the cervical esophagus to the esophagogastric mucosal junction. Idiopathic esophageal submucosal hematoma is often prone to a bleeding tendency of an underlying disorder. The patient had a history of essential thrombocythemia (ET) and was taking aspirin. She successfully recovered after aspirin discontinuation and conservative treatment; however, died of cardiopulmonary arrest in the ward on day 9 of hospitalization. The autopsy revealed that the cause of death was pulmonary thromboembolism. This is the first report of ET with submucosal hematoma of the esophagus. The possibility of an esophageal submucosal hematoma should be considered when patients with ET complain of chest pain since ET and treatment with aspirin are considered risk factors for bleeding. Additionally, close attention should be focused on the risk of developing thrombosis if a patient with myeloproliferative neoplasm is required to discontinue antithrombotic therapy due to a bleeding event.

Background: Kawasaki disease (KD) is a systemic vasculitis syndrome that occurs most frequently in children. Most clinical and pathological studies have focused on its coronary artery lesions. To date, no detailed studies of the aorta have been conducted. We studied KD autopsy cases with the aims of clarifying the time-course of changes in aortic lesions, the differences in the inflammatory cells and degree of inflammation at various aortic sites, and the progression of the inflammation., Materials and Methods: The study materials were aortic specimens taken from 37 KD autopsy cases (acute phase: 19; remote phase: 18). Twenty-seven of the cases also had coronary aneurysms. We chose 3 aortic sites, i.e., the thoracic aorta, aortic root and aortic bifurcation, and we histologically observed and compared those sites in regard to the changes with time, the kinds of infiltrating cells and the number of inflammatory cells. We also observed the relationship between the vasa vasorum and inflammatory cell localization in the tunica media, and examined the progression of inflammation in the tunica media., Results: Destruction of the vascular architecture was not seen in any of the 37 cases, but inflammatory cell infiltration was observed in 90% of the acute-phase cases. The inflammatory cell infiltration involved the tunica intima and tunica adventitia of the aorta on the 6th disease-day, and all layers of the aorta on the 13th disease-day; the infiltration peaked on the 18th disease-day. The infiltration gradually disappeared thereafter, and no significant infiltration was seen in the remote phase. The infiltrating inflammatory cells consisted mainly of CD163-positive macrophages. Comparison of the 3 sites of the aorta showed that the inflammatory cell infiltration was more severe in the aortic root and aortic bifurcation than in the thoracic aorta. The progression of inflammation to the aortic tunica media from the adventitia showed 2 patterns: 1 in which macrophages were aggregated around the vasa vasorum; and a second in which there was no such aggregation around the vasa vasorum, but there was diffuse inflammatory cell infiltration of the tunica media. In addition to this, there were findings of direct infiltration of cells from the tunica intima into the tunica media., Conclusion: Inflammation in KD occurs in the aorta. The changes with time and the kinds of infiltrating cells were the same as reported to date for coronary arteries in KD. There were differences in the degree of inflammation among the 3 aortic sites. It can be thought that the inflammation from the adventitia to the media progresses via the vas vasorum, and also, there is a possibility of spreading directly. From the intima to the media, inflammation spreads directly. However, formation of aneurysms and destruction of the vascular architecture of the aorta were absent in this study, unlike in coronary arteries., (Copyright © 2020. Published by Elsevier Inc.)

Objectives: Using a murine model of systemic Kawasaki disease (KD)-like vasculitis induced by Candida albicans cell-wall-derived mannan · β-glucan · protein complexes, the objective was to elucidate the relationships of β-glucan receptor dectin-1 (D1) and α-mannan receptor dectin-2 (D2) to the onset of that vasculitis. Methods: The incidence and histological severity of vasculitis were compared among mice lacking the genes for D1 or D2 (i.e. D1 -/- and D2 -/- ) and wild-type (WT) mice. Results: The incidences of vasculitis in the three animal groups were 100% (18/18) in the WT group, 100% (18/18) in the D1 -/- group, and 0% (0/18) in the D2 -/- group. In the WT and D1 -/- mice, severe inflammatory cell infiltration, consisting mainly of neutrophils and macrophages, was seen in the aortic root and the coronary arteries. On the other hand, in the D2 -/- mice, not even mild vascular lesions such as endoarteritis were seen. Conclusion: Recognition of α-mannan by D2 played an important role in the onset of vasculitis in the studied murine model.

BACKGROUND Pleomorphic adenoma of the salivary gland is a common benign tumor of the parotid gland. However, pleomorphic adenoma arising in the minor salivary glands, including the nasopharynx, is uncommon. This report is of a case of nasal pleomorphic adenoma in which the preoperative imaging findings were consistent with the histological features of pleomorphic adenoma of the minor salivary gland, which differs from that of pleomorphic adenoma of the major salivary gland. CASE REPORT A 56-year-old Japanese man was referred to the department of otolaryngology following nasal endoscopy performed at a referral center that identified a right nasal mass. The findings of contrast-enhanced magnetic resonance imaging (MRI) were consistent with a pleomorphic adenoma arising in the nasal septum. Needle biopsy and histology confirmed the diagnosis of pleomorphic adenoma. The tumor was resected using endoscopic surgery, and the histology confirmed the diagnosis of pleomorphic adenoma covered by normal nasal mucosa. CONCLUSIONS This case showed that pleomorphic adenoma arising in the nasal minor salivary gland had typical MRI and histological findings and was a submucosal lesion. Preoperative MRI supported the approach to surgical resection to ensure complete excision.

Invasion of host cells by apicomplexan parasites is mediated by proteins released from microneme, rhoptry, and dense granule secretory organelles located at the apical end of parasite invasive forms. Microneme secreted proteins establish interactions with host cell receptors and induce exocytosis of the rhoptry organelle. Rhoptry proteins are involved in target cell invasion as well as the formation of the parasitophorous vacuole in which parasites reside during development within the host cell. In Plasmodium merozoites, the rhoptry neck protein (RON) complex consists of RON2, RON4, and RON5, and interacts with apical membrane antigen 1 (AMA1) as a critical structure of the invasion moving junction. PfRON12 is known to localize to the rhoptry neck of merozoites, but its function remains obscure. The roles of RON proteins are largely unknown in sporozoites, the second invasive form of Plasmodium which possesses a conserved apical end secretory structure. Here, we confirm that RON12 is expressed in the rhoptry neck of merozoites in rodent malaria parasites, whereas in contrast we show that RON12 is localized to the rhoptry body in sporozoites. Phenotypic analysis of Plasmodium berghei ron12-disrupted mutants revealed that RON12 is dispensable for sporogony, invasion of mosquito salivary glands and mouse hepatocytes, and development in hepatocytes., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background/objective: To examine tenascin C (TN-C) expression in coronary artery lesions (CALs) and myocardial lesions (MLs) in Kawasaki disease (KD)., Methods and Results: Twenty-five KD autopsy cases (post-KD-onset range of 6 days to 17 years) were examined in this study. Time-course analysis based on the disease day was performed of the histological findings for the CALs and MLs, as well as the localization and intensity of expression of TN-C. TN-C expression was observed to coincide with the areas where inflammatory cell infiltration was present in both coronary arteries and myocardium during the acute stage of KD, and the intensity of its expression correlated with the degree of inflammation. Obvious TN-C expression persisted in the thickened intima and media of CALs even after Disease Day 27. However, in spite of the presence of inflammatory cell infiltration, TN-C expression became weaker in the adventitia and surrounding connective tissue. After 8 months or more, TN-C was not expressed in the vasculitis scars of most cases, but expression was observed around newly formed vessels in the thickened intima and around recanalized vessels after thrombotic occlusion., Conclusions: The findings suggest a correlation between the degree of inflammation and TN-C expression in the cardiovascular lesions of acute-stage Kawasaki disease., (Copyright © 2018 Elsevier Inc. All rights reserved.)

The unexpected formations of fused polycyclic disilenes 2 a and (E),(Z)-3 b by the reduction of the 1,2-dibromodisilanes 5 a (R=Me) and 5 b (R=iPr) bearing bicyclo[1.1.1]pentasilanyl (BPS) groups is reported. The disilenes 2 a and (E),(Z)-3 b were characterized by a combination of NMR spectroscopy and X-ray diffraction analysis (XRD). The reduction of 5 b in the presence of 2,3-dimethyl-1,3-butadiene provided an ene adduct of the disilene 1 b bearing BPS groups, which suggested that an initial product of the reduction of 5 b was the disilene 1 b. Thermal reactions of 2 a and (E),(Z)-3 b afforded the highly strained saturated silicon clusters 4 a and 4 b. A computational study suggested that the transformation of 1 to 2, 3, or 4 can involve silyldisilene-disilanylsilylene rearrangement reactions and insertion reactions of a silylene into a Si-Si bond., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A fascinating but still rare bicyclic siloxane, bicyclo[3.3.3]pentasiloxane, was synthesized by the oxidation of a bicyclic silicon cluster and characterized using a combination of NMR spectroscopy and X-ray diffraction analysis. The bridgehead OSiMe 3 groups of the siloxane were selectively and efficiently converted to O - K + (siloxide) by treating with t BuOK in the presence of 18-crown-6-ether. The resulting siloxides provided various bridgehead-functionalized bicyclo[3.3.3]pentasiloxanes after treatment with electrophiles.

Kawasaki disease (KD) is the commonest vasculitic syndrome. It affects medium-sized arteries, principally the coronary arteries. Histologically, coronary arteritis begins at 6 to 8 days after the onset of KD and the inflammation rapidly involves all layers of the artery. This results in severe damage to the structural components of the artery leading to arterial dilation. The inflammatory infiltrate in KD arteritis is characterized predominantly by infiltration of monocytes and macrophages. Activated neutrophils, monocytes and macrophages are believed to be involved in the initial stage of coronary arteritis. Inflammatory cell infiltration may continue for up to 25 days of disease following which the inflammatory cells gradually decline in number. Inflammatory lesions in the arteries are relatively synchronous as they evolve from an acute to the chronic stage. If a giant aneurysm remains or vessel recanalization occurs after thrombotic occlusion of an aneurysm, the remodeling of vascular structures may continue for a much longer time., (© 2017 Asia Pacific League of Associations for Rheumatology and John Wiley & Sons Australia, Ltd.)

Rodent malaria is a useful model for evaluating the efficacy of malaria vaccine candidates; however, labor-intensive microscopic parasite counting hampers the use of an in vivo parasite challenge in high-throughput screening. The measurement of malaria parasite lactate dehydrogenase (pLDH) activity, which is commonly used in the in vitro growth inhibition assay of Plasmodium falciparum, may be the cheapest and simplest alternative to microscopic parasite counting. However, the pLDH assay has not been applied in the in vivo rodent malaria model. Here, we showed that the pLDH assay is reliable and accurately determines parasitemia in the rodent malaria model. pLDH activity measured using a chromogenic substrate reflects the parasite number in the blood; it allows fast and easy assessment using a conventional microplate reader. To validate this approach, we synthesized recombinant PyMSP1-19 protein (rPyMSP1-19) using a wheat germ cell-free protein synthesis system and immunized mice with rPyMSP1-19. The antisera showed specific reactivity on the surface of the Plasmodium yoelii merozoite and immunized mice were protected against a lethal P. yoelii 17 XL challenge. The pLDH assay quickly and easily demonstrated a significant reduction of the parasite numbers in the immunized mice. Accordingly, the pLDH assay proved to be an efficient alternative to rodent malaria parasite counting, and may therefore accelerate in vivo vaccine candidate screening., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Glioma stem cells (GSCs) have the capacity to repopulate tumors and mediate resistance to radiotherapy and chemotherapy. The Notch signaling pathway is important in proliferation, stem cell maintenance, cell differentiation, and tumorigenesis in GSCs. In this study, we compared CD133, Notch, and VEGF expressions in histological sections of primary and recurrent glioblastomas after radiotherapy and chemotherapy. In vitro study, the γ-secretase inhibitor inhibited NICD, Hes1 and pVEGFR2 expressions in GSCs. GSCs cultured under endothelial conditions undergo endothelial differentiation. Tumor samples were collected from 27 patients at the time of tumor recurrence. We used immunohistochemical techniques to compare expression of CD133, Notch-1 and VEGF. Expressions of CD133-, Notch-1-, and VEGF-positive glioma cells were higher in recurrent glioblastoma after radiotherapy and chemotherapy. To determine the clinical importance of Notch-1 expression in glioblastoma, we analyzed 15 patients who had received bevacizumab therapy followed by a second surgery at recurrence. OS was significantly longer in cases with Notch-1 negativity (8.8 months) than in those with I Notch-1 positivity (6.8 months). We noted that GSCs have the potential for endothelial differentiation with Notch activity. We believe that Notch-1 is a potential target and/or biomarker for antiangiogenic treatments.

Objectives: Various inflammatory cytokines, including tumor necrosis factor-α (TNF-α), have been reported to play roles in Kawasaki disease (KD). Recently, anti-TNF-α therapy was reported to show efficacy in patients who do not respond to high-dose intravenous immunoglobulin therapy. However, there are many gaps in our understanding of the role that TNF-α plays in the development of KD arteritis as well as whether anti-TNF-α therapy causes any histological changes in the arteritis. Accordingly, the present histopathological study was carried out to elucidate the inhibitory effect of anti-TNF-α therapy on vasculitis as well as the role of TNF-α in the development of vasculitis in a murine model of KD vasculitis., Methods: We used two anti-TNF-α drugs (etanercept and infliximab) to treat a Candida albicans-induced murine model of KD vasculitis. We investigated the histopathological changes in terms of the incidence of vasculitis, the scope of lesions and the degree of inflammation., Results: Administration of etanercept to the mice reduced not only the incidence of vasculitis but also the scope of lesions and the degree of inflammation., Conclusion: Based on the histological findings, TNF-α is deeply involved in the development of vasculitis.

Purpose of Review: This review first discusses the pathogenesis of Kawasaki disease based on the results of recently performed studies aimed at identifying Kawasaki disease-susceptibility genes and the results of analyses of the immune system. Following that, we discuss the findings generated using a murine Kawasaki disease arteritis model and speculate regarding the mechanism of Kawasaki disease onset based on immune function aberrations seen in that model., Recent Findings: Recent advances in gene analysis studies of Kawasaki disease are contributing not only to prediction of disease susceptibility but also to improving our understanding of the pathogenesis of Kawasaki disease and development of new improved therapies. In addition, Th17/Treg imbalance is observed in patients with acute-phase Kawasaki disease. Th17/Treg imbalance may be an important factor causing disturbed immunological function. IL-17 induced by Th17 cells have proinflammatory properties and act on inflammatory cells, thereby inducing expression of cytokines and chemokines and resulting in tissue inflammation., Summary: Kawasaki disease vasculitis may be triggered by aberrant activation of inflammatory cytokines mediated by IL-17 that is produced by Th17 cells that have been activated by some infectious agent(s).

Kawasaki disease (KD) is considered to be a kind of systemic vasculitis syndrome. It most frequently affects infants and young children and primarily invades medium-sized muscular arteries, including the coronary arteries. The etiology of KD is unknown, but epidemiological data suggest involvement of infectious agents, such as bacteria and viruses, in the onset of KD. In addition, host genetics underlie the disease's pathogenesis. Histologically, coronary arteritis begins 6-8 days after KD onset, and inflammation of all layers of the artery rapidly ensues. The inflammation spreads completely around the artery, resulting in severe damage to structural components. Then, the artery begins to dilate. KD arteritis is characterized by inflammation consisting of marked accumulation of monocytes/macrophages. Aberrant activation of monocytes/macrophages is thought to be involved in the formation of vascular lesions. Inflammatory-cell infiltration persists until about the 25th day of the disease, after which the inflammatory cells gradually decrease in number. Lesions in all arteries are relatively synchronous, as they evolve from acute to chronic injury. If a giant aneurysm remains or vessel recanalization occurs after thrombotic occlusion of an aneurysm, remodeling of the vascular structure, sometimes including even reocclusion, continues even in the remote stage.

Aims:   To review the histopathological features of cervical LNs, and to clarify the changes in extracervical LNs, in acute Kawasaki disease (KD)., Methods and Results:   The samples were obtained from 33 patients with acute-phase KD. We divided the LNs into those in the neck (n = 23) and those located elsewhere (n = 26), and investigated them histologically. Changes occur not only in the cervical region, but also in LNs throughout the body. Most lymphadenopathy is non-specific, caused by sinus expansion and paracortical zone enlargement, but there are also necrotic lesions of various sizes that can be surmised to result from ischaemic changes in some LNs. Necrotic foci start to develop immediately below the capsule, and are accompanied by fibrin thrombi in the small vessels and perivascular nuclear debris. Especially in the case of cervical LNs with necrosis, a high degree of non-purulent inflammation develops in the LN capsule and surrounding connective tissue., Conclusions:   In addition to lymphadenopathy with necrosis, KD should be suspected if there is non-purulent inflammation of the LN capsule and/or surrounding connective tissue featuring mainly monocytes/macrophages., (© 2012 Blackwell Publishing Limited.)

Aims: To elucidate the histopathological characteristics of myocarditis in acute-phase Kawasaki disease (KD)., Methods and Results: The examined materials were from 29 autopsied KD patients who died within 40 disease days following onset. Each heart was divided into three levels: base, middle and apex. At each of these levels, the myocardium was divided further into the epicardial, middle and endocardial layers, and the time-courses of the changes in the myocarditis and the distribution of inflammation were analysed. Inflammatory cell infiltration, consisting mainly of lobulated leucocytes and large mononuclear cells, was seen in the myocardial interstitium in all cases. Inflammatory cell infiltration was already seen by disease day 6 in a patient with no coronary arteritis; it became prominent after day 10 and gradually disappeared after day 20. Myocarditis was initially distributed diffusely throughout the heart, but after day 10 it was localized in the base and epicardial layer., Conclusions: In KD, myocarditis develops even earlier than epicardial coronary arteritis; it peaks by disease day 10 and then disappears gradually after day 20. The myocarditis is distributed unevenly, ranging from the entire heart to the epicardial layer of the base of the heart., (© 2012 Blackwell Publishing Limited.)

Background: The objectives of this study were to clarify the details of pediatric vasculitic diseases on the basis of Japanese autopsy reports and determine whether there were cases of probable Kawasaki disease (KD) even before KD came to be widely recognized as a disease entity., Methods and Results: Systemic vasculitis autopsy cases aged 15 years or less were selected from the total of 1,335,045 autopsy cases listed in the Annual of Pathological Autopsy Cases in Japan from 1958 through 2008. Those cases were classified into 14 disease groups and then analyzed with regard to various details. There were 380 autopsy cases of vasculitis in children (0.03% of the total autopsy cases). More than half were KD, and other diseases included unclassified vasculitis, polyarteritis nodosa, purpuric vasculitis, Takayasu arteritis, etc. The first recorded case of KD autopsy occurred in 1969. Up until 1976 there was a great difference in the number of autopsies between pediatric vasculitis and KD. However, after 1977 their numbers were in close agreement. The autopsy findings for 24 of 125 child vasculitis autopsies performed before 1976 and diagnosed as non-KD were consistent with KD., Conclusions: Although autopsies of pediatric vasculitis cases are extremely rare, the majority consists of KD. Moreover, it is likely that autopsy cases that were probably KD first appeared in the early 1960s.

Unlabelled: The incidence of panvasculitis in the coronary arteries and aortic root was 100% in the control group. The incidence of panvasculitis in the MZR group decreased to 50%. Moreover, the scope and severity of the inflammation of those sites were significantly reduced in the MZR group as well as the IgG group. On the other hand, increased cytokines and chemokines, such as IL-1α, TNF-α, KC, MIP-1α, GM-CSF, and IL-13, in the nontreatment group were significantly suppressed by treatment with MZR, but the MCP-1 level increased. In addition, IL-1α, TNF-α, IL-10, IL-13, and MIP-1α were suppressed by treatment in the IgG group., Background: Intravenous immunoglobulin (IVIg) treatment results in an effective response from patients with acute-phase Kawasaki disease (KD), but 16.5% of them remain nonresponsive to IVIg. To address this therapeutic challenge, we tried a new therapeutic drug, mizoribine (MZR), in a mouse model of KD, which we have established using injections of Candida albicans water-soluble fractions (CAWS)., Methods: CAWS (4 mg/mouse) were injected intraperitoneally into C57BL/6N mice for 5 consecutive days. MZR or IgG was administered for 5 days. After 4 weeks, the mice were sacrificed and autopsied, the hearts were fixed in 10% neutral formalin, and plasma was taken to measure cytokines and chemokines using the Bio-Plex system., Results: The incidence of panvasculitis in the coronary arteries and aortic root was 100% in the control group. The incidence of panvasculitis in the MZR group decreased to 50%. Moreover, the scope and severity of the inflammation of those sites were significantly reduced in the MZR group as well as the IgG group. On the other hand, increased cytokines and chemokines, such as IL-1α TNF-α, KC, MIP-1α, GM-CSF, and IL-13, in the nontreatment group were significantly suppressed by treatment with MZR, but the MCP-1 level increased. In addition, IL-1α, TNF-α, IL-10, IL-13, and MIP-1α were suppressed by treatment in the IgG group., Conclusion: MZR treatment suppressed not only the incidence, range, and degree of vasculitis, but also inflammatory cytokines and chemokines in the plasma of the KD vasculitis model mice, suggesting that MZR may be useful for treatment of KD.

A 58-year-old female patient presented with the sudden onset of left upper quadrant pain. The physical examination revealed the presence of shock status. Abdominal computed tomography revealed splenomegaly with a huge mass inside the spleen, and massive fluid collection in the abdominal cavity. After splenic artery embolization, laparotomy was performed. The operative findings revealed intra-abdominal hemorrhage and rupture of the lower pole of the spleen. Furthermore, a palpable solid mass was observed at the splenic hilum, and distal pancreatectomy with splenectomy was performed. The macroscopic findings revealed a pancreatic tail tumor at the splenic hilum directly invading the splenic parenchyma. Microscopic examinations showed the tumor to consist of squamous cell carcinoma. Furthermore, old and new thrombi were observed inside small splenic arteries. These findings were considered to represent invasion of pancreatic adenosquamous carcinoma to the spleen, and rupture of the spleen was attributed to splenic ischemia resulting from cancer invasion and splenic vein obstruction.

Primary cardiac synovial sarcoma is a rare disease. A 51-year-old man visited our hospital with the chief complaint of palpitations and shortness of breath while exercising. Copious bloody pericardial effusion and a multicystic intrapericardial tumor were detected. A primary cardiac malignant tumor was suspected, an open-chest tumor resection was performed with the objectives of diagnosis and treatment. Histologically, the tumor cells were uniformly spindle-shaped with an ovoid or oval nucleus, they had proliferated in fascicular fashion. In addition myxoid degeneration, a hemangiopericytomatous vascular pattern and pseudorosette formation were seen in some areas of the tumor. Based on the histopathological and immunohistochemical findings and reverse transcription polymerase chain reaction detection of SS18-SSX1 fusion transcripts, a monophasic fibrous type synovial sarcoma was diagnosed. Postoperative radiation therapy was administered and there had been no recurrence 9 months after the surgery., (© 2010 The Authors. Pathology International © 2010 Japanese Society of Pathology and Blackwell Publishing Asia Pty Ltd.)

We investigated the inhibitory effect of human immunoglobulin (h-Ig) on the development of coronary arteritis in a murine model of vasculitis induced with a Candida albicans water-soluble fraction (CAWS). CAWS was intraperitoneally injected to C57BL/6 mice for 5 days. Then h-Ig was administered according to various schedules. The animals were sacrificed in week 5, and the status of vasculitis in the coronary arteries and the aortic root was investigated histologically. The groups in which h-Ig was administered for 5 days from day 3 and from day 5 of the experiment showed a significant reduction in the incidence of panvasculitis. In addition, the scope and severity of the inflammation of the aortic root and the coronary arteries were reduced in both groups. In the group administered h-Ig for 5 days from day 1 and the group administered a high dose of h-Ig once on day 1 or day 3, no suppression of development of vasculitis was observed. The h-Ig acted by suppressing the generation and progression of vasculitis in this CAWS-induced murine vasculitis model.

The patient was a 40-year-old Japanese woman. At 37 years of age she underwent stent implantation in LAD#7 for an acute myocardial infarction. Subsequently, coronary intervention was performed four times because of occlusion of the stent. Sudden death occurred at 40 years of age due to ventricular tachycardia. Clinically, the patient had had no history of collagen disease, anti-phospholipid antibody syndrome or coagulation disorder. The autopsy revealed only very mild atherosclerotic changes in the aorta and various other organs, but concentric thickening of the intima was observed in all three branches of the coronary arteries. Also, aneurysms accompanied by calcification were observed at each of LAD #6, LCx #11 and RCA #4PD. The stent was occluded with a thrombus, and the vascular walls showed infiltration by lymphocytes, plasma cells and numerous eosinophils. The eosinophil infiltration was confined to the site of the stent. It was surmised that the patient had experienced late stent thrombosis due to a hypersensitivity reaction to the DES on the basis of a development of a state of high susceptibility to thrombus formation because of a coronary aneurysm. The aneurysm was suspected of being a post-inflammatory change of Kawasaki disease.

Kawasaki disease is a disease of unknown etiology that most frequently affects infants and children under 5 years of age. Inflammation occurs in medium-sized muscular arteries throughout the body including the coronary artery, being classified as a systemic vasculitis syndrome. Histopathological investigations of Kawasaki disease have mainly focused on the coronary artery because it is directly associated with the cause of death. However, to identify the cause and pathology of Kawasaki disease, it is necessary to investigate lesions of whole organs. Thus, we attempted to review lesions in organs other than the heart and hypotheses of pathogenesis recently attracting attention.

Clinical and epidemiologic features suggest infectious agent or agents as a possible cause of Kawasaki disease; however, the etiology of Kawasaki disease still remains unknown. A number of microorganisms including bacteria, viruses, rickettsiae etc. were hypothesized as an etiology of the illness. Unfortunately, no specific agent that provides reproducible evidence has yet reported. The differences of histology between vasculitic disorders indicate the differences of etiology and pathogenesis. The histological characteristics that abnormal activation of monocytes/macrophages is caused in the vascular lesions of Kawasaki disease can be of help when considering the etiology of Kawasaki disease.

There have been very few reports in Japan of patients with allergic fungal sinusitis (AFS). We describe two cases caused by Bipolaris spicifera and Schizophyllum commune. The patients were a 70-year-old male (Case 1) and a 55-year-old female (Case 2). Both presented with nasal obstruction and purulent nasal discharge. CT scans revealed each to have a soft tissue mass extending from the ethmoid sinus to the sphenoid sinus. In addition, pathological studies on the contents of the paranasal sinuses of both patients revealed the presence of fungal elements in the allergic mucin. Microbiological studies resulted in the recovery of Bipolaris spicifera from Case 1 and Schizophyllum commune from Case 2. To date there have been no reports of AFS due to these two fungi in Japan. It is very important in the diagnosis of AFS to demonstrate the presence of fungal elements in the allergic mucin. Squash cytology of the paranasal sinus contents was especially useful for proving the presence of fungi.

Detachment of mesothelial cells is an early step in adhesion of the human pleura. To elucidate this process, we used adhesion molecules as the targets of primary antibody and performed immunohistochemical staining of the mesothelial cells that cover the surface of the sites of pleural adhesion and the macrophages that migrate from connective tissue. The surface of the adhesion site that was formed as a result of edematous and villiform elongation of the connective tissue underlying the visceral pleura was covered with mesothelial cells. However, there was partial detachment of the mesothelial cells caused by adherence to macrophages that had migrated from within the connective tissue, and that adherence was mediated by adhesion molecules. We demonstrated that both mesothelial cells and macrophages each express both CD54 and CD11a, important adhesion molecules. It was surmised that the detachment of the mesothelial cells is the result of interaction with the macrophages via those adhesion molecules and that over time it progresses to pleural adhesion.

Background: There has been no morphological evidence that polymorphonuclear leukocytes (PMNL) infiltrate the coronary arterial lesions of acute Kawasaki disease (KD) patients, although clinical data indicate the activation of PMNL., Methods: The experimental materials consisted of eight autopsy patients who died during the acute phase of KD. Duration of the illness ranged from 6 to 32 days. The tissues were fixed and embedded in paraffin. Hematoxylin and eosin, elastica van Gieson and azan-Mallory stainings were performed for routine histological examination. In addition, antibodies to CD3, CD20, CD68 and neutrophil elastase were used for immunohistochemistry to identify infiltrating cells in arterial lesions., Results: The inflammatory cells that appeared in the coronary arterial lesions were mainly composed of macrophages in all patients. In addition, numerous neutrophils were also identified in the coronary arterial lesions of the patients who died 10 days after the onset of KD. Neutrophilic infiltration reached a peak earlier than the peaks of CD68+ macrophages, CD3+ T lymphocytes and CD20+ B lymphocytes., Conclusions: These results suggest that neutrophils are involved in the damage occurring to coronary arteries in the early stage of KD. Vasodilation might occur as a result of injury to vascular walls caused by neutrophils, as well as macrophages.

We describe a case of allergic fungal sinusitis (AFS) caused by Bipolaris spicifera, the first case reported in Japan. A 70-year-old man was admitted to our hospital because of diplopia following bilateral nasal obstruction and discharge. Radiological studies using computed tomographic scan showed a large soft tissue mass occupying the right frontal, bilateral ethmoid and sphenoid sinuses. He underwent drainage surgery and histopathological examination of the contents of the paranasal sinuses revealed scattered fungal hyphae within "allergic mucin". By cytological examination, these hyphae showed septation at irregular intervals, and were swollen to various sizes. Microbiological studies identified the fungus as Bipolaris spicifera. The presence of allergic mucin and scattered fungal hyphae were very important findings in making a diagnosis of AFS histopathologically, so squash cytology of the contents of the paranasal sinuses was quite useful to observe fungal elements and identify the strain in this case.