Search

Twenty autopsy cases with 2009 pandemic influenza A (2009 H1N1) virus infection, performed between August 2009 and February 2010, were histopathologically analyzed. Hematoxylin-eosin staining, immunohistochemistry for type A influenza nucleoprotein antigen, and real-time reverse transcription-PCR assay for viral RNA were performed on formalin-fixed and paraffin-embedded specimens. In addition, the D222G amino acid substitution in influenza virus hemagglutinin, which binds to specific cell receptors, was analyzed in formalin-fixed and paraffin-embedded trachea and lung sections by direct sequencing of PCR-amplified products. There were several histopathological patterns in the lung according to the most remarkable findings in each case: acute diffuse alveolar damage (DAD) with a hyaline membrane (four cases), organized DAD (one case), acute massive intra-alveolar edema with variable degrees of hemorrhage (three cases), neutrophilic bronchopneumonia (five cases) and tracheobronchitis with limited histopathological changes in alveoli (four cases). In two cases, the main findings were due to preexisting disease. Influenza virus antigen was only detected in the respiratory tract in 10 cases by immunohistochemistry. The antigen was detected in type II pneumocytes (three cases) in the epithelial cells of the trachea, bronchi and glands (six cases), and in the epithelial cells in both of the above (one case). The four cases with acute DAD presented with antigen-positive type II pneumocytes. In one case, the D222G substitution was detected in the lung as a major sequence, although 222D was prominent in the trachea, suggesting that selection of the viral clones occurred in the respiratory tract. In five cases, the pathogenesis of 2009 H1N1 was confirmed to be viral infection in pneumocytes, which caused severe alveolar damage and fatal viral pneumonia. Further studies on both host and viral factors in autopsy or biopsy materials will be essential to elucidate the other pathogenic factors involved in influenza virus infection.

We report the pathological and virological findings of the first autopsy case of the 2009 pandemic influenza (A/H1N1pdm) virus infection in Japan. A man aged 33 years with chronic heart failure due to dilated cardiomyopathy, mild diabetes mellitus, atopic dermatitis, bronchial asthma, and obesity died of respiratory failure and multiple organ dysfunction syndrome. Macroscopic examination showed severe pulmonary edema and microscopically the lung sections showed very early exudative-stage diffuse alveolar damage (DAD). Immunohistochemistry revealed proliferation of the influenza (A/H1N1pdm) virus in alveolar epithelial cells, some of which expressed SAalpha2-3Gal on the cell surface. Influenza (A/H1N1pdm) virus genomic RNA and mRNA were also detected in alveolar epithelial cells. Real-time PCR revealed 723 copies/cell in the left lower lung section from which the influenza (A/H1N1pdm) virus was isolated. Electron microscopic analysis revealed filamentous viral particles in the lung tissue. The concentrations of various cytokines/chemokines in the serum and the autopsied lung tissue were measured. IL-2R, IL-6, IL-8, IL-10, IFN-alpha, MCP-1, and MIG levels were elevated in both. These findings indicated a case of viral pneumonia caused by influenza (A/H1N1pdm) virus infection, showing characteristic pathological findings of the early stage of DAD.

CAWS, a water-soluble extracellular polysaccharide fraction obtained from the culture supernatant of Candida albicans, is one of the fungal pathogen-associated molecular patterns (PAMPs). It has been reported to show potent activity inducing arteritis and coronaritis in mice. Especially, CAWS-induced arteritis has a 100% incidence and severe mortality in the DBA/2 mouse strain. This artificial vasculitis was reported to provide a good murine model of Kawasaki disease and other inflammatory vascular disease. However, severe mortality was observed only in DBA/2 mice, which is a CAWS-sensitive strain. In this study, to clarify the mechanisms of CAWS-induced arteritis and mortality, we investigated microscopic histopathological changes in cardiovascular tissues in DBA/2 mice. Severe inflammatory infiltration was observed from the external elastic lamina in the aorta and proximal coronary arteries within 1 week after CAWS administration. Severe stenosis of the aorta and coronary arteries was observed more than 3 weeks after CAWS administration. Fibrinoid necrosis was observed in these vessel walls. All CAWS-treated mice died between the fifth and twelfth week after administration. Severe inflammatory change with aortic valve transformation suggested that CAWS-treated mice died of valvular endocarditis or cardiac dysfunction. Based on the simple induction method and complete incidence, these data suggest that CAWS-induced arteritis is a good model of not only Kawasaki disease but also other cardiovascular diseases such as valvular endocarditis.

Several point mutations of alpha(1)-antitrypsin cause a perturbation in protein structure with consequent polymerization and intracellular accumulation. The retention of polymers of alpha(1)-antitrypsin within hepatocytes results in protein overload that in turn is associated with juvenile hepatitis, cirrhosis, and hepatocellular carcinoma. The detection of alpha(1)-antitrypsin polymers and understanding the molecular basis of polymer formation is of considerable clinical importance. We have used a monoclonal antibody (ATZ11) that specifically recognizes a conformation-dependent neoepitope on polymerized alpha(1)-antitrypsin to detect polymers within hepatocytes of individuals with alpha(1)-antitrypsin deficiency. Paraffin-embedded liver tissue specimens were obtained from individuals who were homozygous for the Z (Glu342Lys), Mmalton (52Phe del), and Siiyama (Ser53Phe) alleles of alpha(1)-antitrypsin that result in hepatic inclusions and profound plasma deficiency. Immunohistological staining with a polyclonal anti-human alpha(1)-antitrypsin antibody showed hepatic inclusions in all 3 cases, while ATZ11 reacted with hepatic inclusions formed by only Z alpha(1)-antitrypsin. Polymers of plasma M and Z alpha(1)-antitrypsin prepared under different conditions in vitro and polymers of recombinant mutants of alpha(1)-antitrypsin demonstrated that the monoclonal antibody detected a neoepitope on the polymerized protein. It did not detect polymers formed by a recombinant shutter domain mutant (that mirrors the effects of the Siiyama and Mmalton variants), polymers formed by cleaving alpha(1)-antitrypsin at the reactive loop, or C-sheet polymers formed by heating alpha(1)-antitrypsin in citrate. In conclusion, the ATZ11 monoclonal antibody detects Z alpha(1)-antitrypsin in hepatic inclusions by detecting a neoepitope that is specific to the polymeric conformer and that is localized close to residue 342.

Although α1-antitrypsin (AAT) deficiency is one of the most common hereditary diseases and a recognized cause of emphysema in Caucasians, variants of this deficiency are extremely rare among Orientals. We present here a Japanese emphysema patient with the AAT deficiency variant originally identified as Siiyama. After an 8-year follow-up period, the patient suffered from repeated pulmonary Pseudomonas aeruginosa infection for 4 years. He died suddenly of massive pulmonary hemorrhage. The pathologic examination revealed a necrotic hematoma in the right S10 lobe, which exhibited pneumonia due to cytomegalovirus (CMV) infection. Pulmonary hemorrhage due to CMV can occur and be fatal in patients with emphysema and AAT deficiency.

We experienced an operated case of mechanical obstruction caused by nonspecific multiple ulcers of the small intestine. A 55-year-old female was admitted to the hospital because of ileus in March, 1994. There was a previous history of undergoing partial resection of the small intestine for an ulcer of the small intestine at another hospital 27 years before. She has been treated for iron deficiency anemia at the department of internal medicine in our hospital for 12 years. Once she seemed to be getting better, but the state of ileus developed again. An operation was performed in May, 1994. The ileus was caused by severe stenosis of the small intestine. Her illness was diagnosed as nonspecific multiple ulcers of the small intestine based on the clinical course, intraoperative findings, and macro- and microscopic findings of the resected tissues. Mechanical obstruction caused by this disease rarely occurs. Her sister died of malnutrition due to this disease. Considering intermarriage of her parents, it is suggested that the occurrence of this disease is influenced by some hereditary factors.

A 22-year-old man with acute lymphoblastic leukemia underwent allogeneic stem cell transplantation (allo-SCT) twice, then underwent allo-SCT a third time due to relapse. On day 27, he developed acute respiratory distress, and bilateral interstitial infiltrates were noted on CT images. Despite receiving intensive treatment, the patient died on day 32 from progressive respiratory failure. An autopsy revealed evidence of diffuse alveolar damage caused by the genus Toxoplasma. At present, toxoplasmosis is considered to be a rare infectious complication in Japan. However, the actual incidence of toxoplasmosis may be higher than currently believed due to a lack of suspicion of the diagnosis in patients, difficulty in making a diagnosis and low autopsy rates.

It was reported previously that a Candida albicans water-soluble fraction (CAWS), including a mannoprotein and β-glucan complex, has strong potency in inducing fatal necrotizing arteritis in DBA/2 mice. In this study, histopathological changes and cardiac function were investigated in this system. One mg/day of CAWS was given to DBA/2 mice via peritoneal injection for five days. The CAWS-treated DBA/2 mice were induced aortitis and died at an incidence of 100% within several weeks. Histological findings included stenosis in the left ventricular outflow tract (LVOT) and severe inflammatory changes of the aortic valve with fibrinoid necrosis. Cardiomegaly was observed and heart weight increased 1.62 fold ( 𝑃 < 0 . 0 1 ). Echocardiography revealed a severe reduction in contractility and dilatation of the cavity in the left ventricle (LV): LV fractional shortening (LVFS) decreased from 71% to 38% ( 𝑃 < 0 . 0 1 ), and the LV end-diastolic diameter (LVDd) increased from 2.21 mm to 3.26 mm ( 𝑃 < 0 . 0 1 ). The titer of BNP mRNA increased in the CAWS-treated group. Severe inflammatory changes resulting from CAWS brought about lethal LV dysfunction by aortic valve deformation with LVOT stenosis. This system is proposed as an easy and useful experimental model of heart failure because CAWS arteritis can be induced by CAWS injection alone.

The present study was undertaken to explore whether tumor cells of villous adenomas of the human colon showed an organized expression of differentiation markers. Eleven cases of villous adenomas were examined by employing histochemical techniques, which are useful for characterizing the colonic mucosa, including high iron diamine-alcian blue pH 2.5, lectin stains with DBA, GSA-I and UEA-I, immunostainings for blood group A determinant, lysozyme, and proliferating cell nuclear antigen (PCNA). The results demonstrated that the adenoma tissues showed the organized expression of these sugar moieties or antigens similar to those found in the normal colon crypts. Namely, tumor cells in the upper portions of tumor tissues revealed characteristic features of normal epithelia, lining the upper compartment of the crypts, and contained sialomucins, which possessed DBA reactivity. Tumor cells in the lower portions, on the other hand, resembled epithelia lining the lower compartments of the crypts, contained sulfomucins, showed GSA-I and UEA-I reactivities, and stained for blood group A determinant and lysozyme. PCNA-positive cells were more abundant in the lower portions of the tumor tissues than in the upper portions. It seems likely that cellular differentiation, similar to normal crypt cells, occurs in the tumor tissues.

A 31-year-old female presented to a gynecological clinic complaining of amenorrhea and virilism over a 2-month period. Blood tests revealed high serum total testosterone and free testosterone levels. A left adrenal tumor was identified following computed tomography and she was referred to our clinic where a laparoscopic left adrenalectomy was performed. The tumor weighed 98 g and the pathological diagnosis according to Weiss’ criteria was adrenocortical carcinoma. The post-operative course was uneventful; her serum free testosterone level normalized and regular menstruation was observed 1 month post-operatively. The patient became pregnant 1 year later, resulting in the normal delivery of a girl.

A 67-year-old man was referred to our clinic with a complaint of macroscopic hematuria. He had been treated for schizophrenia in a psychology ward. Computed tomography (CT) scan revealed a left renal tumor 7 cm in size, well enhanced in early phase. Doppler ultrasonography indicated hypervascular left renal tumor. Laparoscopic radical left nephrectomy was performed under the diagnosis ofrenal cancer. Histopathlogical results showed a renal solitary fibrous tumor (SFT) with a hemangiopericytoma-like pattern. Renal SFT is an uncommon tumor. The present case is the 11th reported case of SFT with hemangiopericytoma-like pattern in the Japanese literature.

We describe 2 siblings with multiple gastrointestinal stromal tumors (GISTs) and cutaneous hyperpigmentation. Both had a point mutation of the c-kit gene. The patients were sisters who had exhibited cutaneous hyperpigmentation since their late teens, but the diagnosis of multiple gastrointestinal submucosal tumors was not made until they were 41 and 45 years old. Histologic examination showed that these tumors were GISTs expressing CD34 and Kit protein. Both patients died of GISTs. Single-strand conformation polymorphism analysis showed a mutation of c-kit in tumor DNA extracted from paraffin-embedded specimens. Direct sequencing analysis showed that the point mutation occurred at codon 559 of exon 11 (Val→Ala). The same single-point mutation was detected in DNA extracted from peripheral leukocytes obtained from the younger sister and her 2 children (who had similar general hyperpigmentation) as well as in DNA from a skin biopsy specimen taken from the older sister. The germline mutation at codon 559 of the c-kit gene found in the present familial GISTs differed from that in a previously reported case of familial GISTs. We propose that GISTs caused by a germline mutation of the c-kit gene should be referred to as GIST–cutaneous hyperpigmentation disease. GASTROENTEROLOGY 2001;120:210-215

Concerns over cancer development from exposure to environmental sources of densely ionizing, high linear energy transfer (LET) radiation, such as alpha-particles from radon, is a current public health issue. The study of tumors attributable to high LET irradiation would greatly augment our insights into the biological mechanisms of carcinogenesis. Chronic low-dose-rate internal exposure to alpha-radiation from thorium dioxide deposits following intravascular administration of the radiographic contrast agent Thorotrast is known to markedly increase the risk of cancer development, especially that of hepatic angiosarcomas and cholangiocarcinomas. Although the mechanism is hypothesized to be via cellular damage, DNA being a major target, wrought by the high LET alpha-particles, the specific genes and the actual sequence of events involved in the process of transforming a normal cell into a malignant one are largely unknown. To shed some light on the molecular mechanisms of cancer development during a lifetime exposure to alpha-radiation, we analyzed the most commonly affected tumor suppressor gene in humans, p53, in 20 Thorotrast recipients who developed cancer, mostly of hepatic bile duct and blood vessel origin. Of the 20 cases, 19 were found to harbor p53 point mutations. Moreover, the accompanying non-tumor tissues from these patients also had p53 mutations, albeit at lower frequency. The distribution pattern of the point mutations was significantly different between the non-tumor and tumor tissues, with most mutations in malignant tissues located in the highly conserved domains of the p53 gene. Our results support the idea that p53 mutations are important in the genesis of Thorotrast-induced tumors but that these point mutations are a secondary outcome of genomic instability induced by the irradiation. Additionally, non-tumor cells harboring p53 mutations may gain some survival advantage in situ but mutations in the domains responsible for the formation of structural elements critical in binding DNA may be necessary for a cell to reach full malignancy.

A new form of Geotrichum candidum lipase with a unique positional specificity was found to exist in the culture broth as a minor component together with the well-documented major form. Unlike the major form, which cleaves both the inside and outside ester bonds of triglyceride indiscriminately, the newly isolated form showed some preference for the inside (2-position) ester bond. The new enzyme was also characterized by its own fatty acid specificity, i.e., an outstandingly high activity towards triolein and methyl oleate among the simple triglycerides and fatty acid methyl esters tested. Moreover, the enzyme possessed a specific activity three times as high as the major form. Notable difference in circular dichroism spectra were observed between the two forms, indicating distinct conformational differences. Edman degradation revealed that the N-terminal sequence of the new form differed from that of the major form, thus demonstrating the existence of a novel lipase gene on the chromosome.

The warty disordered lesions of the vulva in three female patients were diagnosed as Bowenoid papulosis on the basis of clinical and histopathological findings. In all three vulvar lesions, human papillomavirus type 16 (HPV 16) DNA was identified by Southern blot hybridization and papillomavirus genus-specific (PGS) antigen was detected in one case immunohistochemically. Furthermore, colposcopic examination revealed the presence of abnormal uterine cervical lesions in two cases. They were found to be intraepithelial neoplasia which harbored HPV 16 DNA and were positive for PGS antigen.

Chronic granulomatous disease (CGD) is based on the dysfunction of phagocytes and characterized by a comparatively uniform granulomatous lesion caused by organisms which do not produce hydrogen peroxide and which are catalase-positive. This report describes two autopsy cases in children, a nine year-two month-old boy and a ten month-old girl, with the clinical manifestations and autopsy findings of CGD and a brief review of all autopsy cases consistent with CGD reported in Japan. In these cases, in addition to the usual CGD lesions, there was a markedly different type of granuloma due to Aspergillus sp., which consisted of multinuclear giant cells alone, or a caseous center surrounded by giant cells. This peculiar type of aspergillosis may correspond to a primary infection, described as pseudotuberculosis aspergillina. It appears that in some CGD patients, macrophages may function normally and sometimes be more activated by these infections than in the normal body. The histochemical and electron microscopic examination of the present cases and a review of the previous cases suggest that the yellowish brown pigment found seems to resemble a ceroid. It is a product of the degradation of leukocytes and tissue elements with subsequent accumulation in phagocytic histiocytes and is not necessarily peculiar to CGD.

Six cases of synovial sarcoma were examined histochemically in order to clarify the components of mucosubstances in the tumor tissues. The tumors were classified into 1) monophasic type, 2) predominantly monophasic type with focal biphasic differentiation, and 3) biphasic type. The former two groups and sarcomatous areas in the biphasic tumors contained various amounts of hyaluronic acid, chondroitin sulfate, and, in some cases, heparitin sulfate. By contrast, the epithelioid regions in the biphasic-type tumors had periodic acid-Schiff-positive glycoproteins which contained various amounts of sialic acid, in addition to hyaluronic acid and chondroitin sulfate. The significance of the presence of glycoproteins in the mesenchymal tumors is emphasized. It seems likely that the synovial sarcomas contain various kinds of mucosubstances and that sensitivity to hyaluronidase treatment is not necessarily the diagnostic criterion of synovial sarcoma.