Colonic stent-induced mechanical compression may suppress cancer cell proliferation in malignant large bowel obstruction.

BACKGROUND: The short-term safety and efficacy of insertion of a self-expandable metallic colonic stent (SEMS) followed by elective surgery, "bridge to surgery (BTS)", for malignant large bowel obstruction (MLBO) have been well described; however, the influence on long-term oncological outcomes is unclear. The aim of this study was to evaluate changes in oncological characteristics in colorectal cancer (CRC) tissues after SEMS insertion, focusing on growth factors, cell cycle and apoptosis. METHODS: From January 2013 to September 2014, a total of 25 patients with MLBO who underwent BTS at our single institution were retrospectively included. Paired CRC tissue samples before (endoscopic biopsy) and after SEMS insertion (surgically resected) were collected from each patient. EGFR, VEGF, Ki-67, p27kip1 and TUNEL expression were determined by immunohistochemistry. RESULTS: No clinical or subclinical perforations evaluated by mechanical ulceration pathologically were observed. Epithelial exfoliation, tumour necrosis, infiltration of inflammatory cells and fibrosis were observed in SEMS-inserted surgically-resected specimens. Overall, 84% (21/25) and 60% (15/25) of patients exhibited no change or a decrease in staining category, respectively, for EGFR and VEGF expression after SEMS insertion. A significant decrease in Ki-67 expression was observed in surgically-resected specimens compared with endoscopic biopsy specimens (P < 0.01). The upstream cell cycle inhibitor, p27kip1, was significantly increased after SEMS insertion (P = 0.049). CONCLUSIONS: Although the long-term safety of BTS should be determined in a future clinical trial, mechanical compression by SEMS may suppress cancer cell proliferation and this result could provide some insights into the issue.

Serum Wisteria floribunda agglutinin-positive Mac-2 binding protein more reliably distinguishes liver fibrosis stages in non-alcoholic fatty liver disease than serum Mac-2 binding protein.

AIM: Serum Mac-2 binding protein (M2BP) and Wisteria floribunda agglutinin-positive Mac-2 binding protein (WFA+ -M2BP) are used to estimate the liver fibrosis stage in chronic liver diseases. However, few head-to-head studies have been carried out to compare the two biomarkers in non-alcoholic fatty liver disease (NAFLD). METHODS: Serum M2BP and WFA+ -M2BP levels were compared against clinical characteristics and liver histological manifestations in the same samples collected from 213 biopsy-proven NAFLD patients. RESULTS: Median levels (range) of M2BP and WFA+ -M2BP were 1.58 (0.70-7.75) pg/mL and 0.85 (0.22-11.32) cut-off index (COI), respectively. Fibrosis stages 1, 2, 3, and 4 were determined in 136, 37, 17, and 23 patients, respectively. Median levels of both biomarkers increased stepwise with fibrosis progression. The M2BP and WFA+ -M2BP levels showed a significant positive correlation (r = 0.643, P = 2.91 × 10-26 ), but a marked discrepancy between both biomarkers was noted in five stage 4 and three stage 1 patients, who had high WFA+ -M2BP but relatively low M2BP levels. Most of these outliers had findings suggestive of more advanced fibrosis. For diagnosing any fibrosis severity, WFA+ -M2BP had greater area under the receiver operating characteristic curve (AUC) and predictive accuracy than M2BP. Among eight fibrosis markers/indices, WFA+ -M2BP yielded the second highest AUC (0.832) and the highest predictive accuracy (82.2%) to diagnose cirrhosis. In addition, WFA+ -M2BP showed the second highest predictive accuracy to diagnose severe fibrosis (78.4%) and significant fibrosis (76.1%). CONCLUSION: This head-to-head comparison suggests that WFA+ -M2BP is superior to M2BP for distinguishing liver fibrosis stages in NAFLD patients. A marked discrepancy between the two biomarkers may be indicative of advanced NAFLD (UMIN000023286).

Relationship Between Immunophenotypes, Genetic Profiles, and Clinicopathologic Characteristics in Small Bowel Adenocarcinoma.

Small bowel adenocarcinoma (SBA) is rare, and scant data exist regarding its molecular and clinicopathologic characteristics. This study aimed to clarify the correlation between immunophenotypes, DNA mismatch repair status, genomic profiling, and clinicopathologic characteristics in patients with SBA. We examined 68 surgical resections from patients with primary SBA for immunohistochemical analyses of CK7, CK20, CD10, CDX2, MUC1, MUC2, MUC4, MUC5AC, and MUC6 expression as well as mismatch repair status. Genomic profiling was performed on 30 cases using targeted next-generation sequencing. Tumor mucin phenotypes were classified as gastric, intestinal, gastrointestinal, or null based on MUC2, MUC5AC, MUC6, and CD10 immunostaining. The expression of these proteins was categorized into 3 classifications according to their relationship to: (1) tumor location: CK7/CK20, MUC4, and MUC6; (2) histologic type: mucinous adenocarcinoma was positive for MUC2 and negative for MUC6; and (3) TNM stage: CD10 was downregulated, whereas MUC1 was upregulated in advanced TNM stages. CDX2 was a specific marker for SBA generally expressed in the small intestine. MUC1 and MUC4 expression was significantly associated with worse prognosis. MUC2 expression correlated with better prognosis, except for mucinous adenocarcinoma. Although the difference was not statistically significant, gastric-type tumors were more frequently located in the duodenum and were absent in the ileum. APC and CTNNB1 mutations were not found in the gastric-type tumors. The SBA immunophenotype correlated with tumor location, biological behavior, and genomic alterations. Our results suggest that the molecular pathway involved in carcinogenesis of gastric-type SBA differs from that of intestinal-type SBA.

The (13)C-butyrate breath test: a new non-invasive method for assessing colitis in a murine model.

The conventional method for the real-time assessment of murine colitis requires a large number of animals. The (13)C-butyrate breath test could be useful for evaluating disease activity and the amelioration of human ulcerative colitis non-invasively. The purpose of this study was to investigate whether this test can be used to assess the phase of inflammation in murine colitis. We investigated the excretion of (13)CO2 measured by the (13)C-butyrate breath test after rectal instillation of butyrate in the DSS colitis model. The colon length, MPO activity, and histological damage were analyzed as parameters. The efficacy of salicylazosulfa-pyridine (SASP) on (13)CO2 excretion was also studied. The (13)CO2 excretion curves in the 0.5% DSS- and 0.75% DSS-treated groups were significantly lower than those in the normal group (P < 0.01, P < 0.01). Good correlation between the results of the breath test and the inflammation parameters was observed. The (13)CO2 excretion curve in DSS murine colitis after the administration of SASP was significantly higher than in the normal group (P < 0.01). The (13)C-butyrate breath test can be used to evaluate the inflammatory phase of DSS murine colitis, and it may be a new non-invasive method for assessing murine colitis.

A case of complete resection of prostate stromal sarcoma after neoadjuvant chemotherapy.

Introduction: Prostatic stromal sarcoma is an extremely rare malignancy of the prostate with a poor prognosis. Case presentation: A 65-year-old man presented with dyschezia, and computed tomography showed a large prostate mass. The diagnosis was prostate stromal sarcoma by transrectal needle biopsy. Magnetic resonance imaging suggested rectal infiltration. The patient underwent 4 courses of neoadjuvant chemotherapy with gemcitabine and docetaxel hydrate followed by total pelvic exenteration. Conclusion: No recurrence has occurred at 5 years after the surgery. This is the first report of complete resection in prostate stromal sarcoma after neoadjuvant chemotherapy with gemcitabine and docetaxel hydrate.

Successful immunosuppressant-free treatment of a drug-induced sarcoidosis-like reaction caused by dupilumab.

We present a case of a drug-induced sarcoidosis-like reaction (DISR) in a 34-year-old female patient who had been receiving dupilumab for eosinophilic rhinosinusitis, for seven months. Computerized tomography scans revealed multiple lymphadenopathies, and biopsies performed on the lung and skin lesions showed the presence of non-caseating granulomas. The patient's serum levels of soluble interleukin-2 receptor and angiotensin-converting enzyme were elevated. There were no findings of Mycobacterium spp, or any other bacterial infections. Based on these findings, it was suspected that the sarcoidosis-like reaction observed in this patient was caused by dupilumab. Switching the patient's treatment from dupilumab to mepolizumab improved the DISR.

Clinical significance of programmed cell death-ligand expression in small bowel adenocarcinoma is determined by the tumor microenvironment.

BACKGROUND: Comprehensive genomic analysis has shown that small bowel adenocarcinoma (SBA) has different genomic profiles from gastric and colorectal cancers. Hence, it is essential to establish chemotherapeutic regimens based on SBA characteristics. The expression of programmed cell death-ligand 1 (PD-L1) and programmed cell death-ligand 2 (PD-L2) in SBA is not fully understood. Anti-PD-L1/PD-1 therapy uses tumor-infiltrating lymphocytes (TILs); therefore, the status of TILs in the tumor microenvironment (TME) may influence their efficacy. The ratio of FoxP3+ to CD8+ T cells has been reported to be useful in predicting the prognosis of digestive system cancers. AIM: To investigate the clinicopathological significance of PD-L1/2 expression according to the status of TILs in SBA tissues. METHODS: We performed immunohistochemical analysis for PD-L1, PD-L2, CD8, FoxP3, and DNA mismatch repair (MMR) proteins using formalin-fixed, paraffin-embedded tissues from 50 patients diagnosed with primary SBA. The immunoreactivities of PD-L1 and PD-L2 were determined separately in tumor cells and tumor-infiltrating immune cells throughout the tumor center and invasive margins, and finally evaluated using the combined positive score (CPS). We assessed CD8+ and FoxP3+ T cells in the intratumoral and tumor-surrounding stroma. Subsequently, we calculated and summed the ratio of FoxP3 to CD8+ T cell counts. Immune-related cell densities were graded as low or high. Immunohistochemical results were compared with clinicopathological factors and patient prognosis. The distribution of cancer-specific survival (CSS) was estimated using the Kaplan-Meier method, and the log-rank test was used to test for significant differences in CSS. A Cox proportional hazard model was also used to assess the effect of tumor variables on CSS. RESULTS: PD-L1 expression was positive in 34% in tumor cells (T-PD-L1) and 54% in tumor-infiltrating immune cells (I-PD-L1) of the cases examined. T-PD-L2 was positive in 34% and I-PD-L2 was positive in 42% of the cases. PD-L1 CPS ≥ 10 and PD-L2 CPS ≥ 10 were observed in 50% and 56% of the cases, respectively. Deficient MMR (dMMR) was 14% of the cases. T-PD-L1, I-PD-L1 and PD-L1 CPS ≥ 10 were all significantly associated with dMMR (P = 0.037, P = 0.009, and P = 0.005, respectively). T-PD-L1, I-PD-L1, and PD-L1 CPS ≥ 10 were all associated with deeper depth of invasion (P = 0.001, P = 0.024, and P = 0.002, respectively). I-PD-L2 expression and PD-L2 CPS ≥ 10 were significantly higher in the differentiated histological type (P = 0.015 and P = 0.030, respectively). The I-PD-L1 and I-PD-L2 levels were significantly associated with better CSS (P = 0.037 and P = 0.015, respectively). CD8-high was significantly associated with less lymph node metastasis (P = 0.047), less distant metastasis (P = 0.024), less peritoneal dissemination (P = 0.034), and earlier TNM stage (P = 0.047). The CD8-high group had better prognosis than the CD8-low group (P = 0.018). FoxP3 expression was not associated with any clinicopathological factors or prognosis. We found that patients with PD-L2 CPS ≥ 10 tended to have worse prognosis in the FoxP3/CD8-low group (P = 0.088). CONCLUSION: The clinicopathological significance of PD-L1/2 expression may differ depending on the TME status. Immune checkpoint inhibitors may improve the prognosis of SBA patients with low FoxP3/CD8 ratio and PD-L2 expression.

Hemochromatosis and Hepatocellular Carcinoma Secondary to Immunoglobulin G4-Related Disease with Hepatopathy: A Case Report.

Immunoglobulin G4-related disease (IgG4-RD) is a recently characterized illness in which lymphocytes and plasma cells infiltrate various anatomical sites. IgG4-hepatopathy, a manifestation of IgG4-RD, is a broader term covering various patterns of liver injury. The clinical course, including the malignant potential of IgG4-RD, remains unclear. Here we report the first case of secondary hemochromatosis and hepatocellular carcinoma (HCC) developing from IgG4-hepatopathy. A 67-year-old man was admitted to our hospital for treatment of deteriorating glucose tolerance. Blood test results showed hypergammaglobulinemia, especially IgG4. He was readmitted 2 months later with dyspnea due to lung disease and pleural effusion, and elevated transaminase levels. He underwent liver and lung biopsies. IgG4-RD was diagnosed and he was treated with steroid therapy, which improved serum IgG4 levels and imaging abnormalities. A follow-up computed tomography (CT) scan conducted 38 months later revealed a tumor (diameter, 50 mm) in liver segments 7 and 8. The resected specimen revealed HCC and abundant siderosis in the background liver, indicating a diagnosis of hemochromatosis. IgG4-positive cells were scarce, probably because of corticosteroid therapy. In the present case, IgG4-RD was well controlled with prednisolone (PSL) and an immunosuppressive agent, and chronic hepatitis was not severe, even though the patient subsequently developed HCC. However, extensive siderosis consistent with hemochromatosis was unexpectedly noted. These findings suggest that secondary hemochromatosis and HCC developed during IgG4-RD with hepatopathy. We believe this case sheds light on IgG4-RD.

Dynamics of global gene expression changes during brain metastasis formation.

As methods of cancer diagnosis and treatment improve, interest in metastatic brain tumors continues to increase. In the present study, we attempted to characterize genetically the dynamic changes occurring during brain metastasis formation by DNA microarray, and attempted to compare these findings with histological observations. Lewis lung carcinoma cells were injected into C57BL/6Ncrj mice carotid arteries. The mice were sacrificed at days 1-9 after injection. We performed histological observation and genome-wide expression profiling using a DNA microarray. In histological observation, tumor cells were observed in capillary vessels at day 1 after injection. At day 3, the tumor cells had begun to proliferate. At day 6, the metastatic foci showed "perivascular proliferations". Next, we performed a pairwise comparison of gene expression microarray data from day 1 to day 9 after injection. The first major change occurred between Phase Two and Phase Three. When hierarchical clustering was performed between different samples using the 867 genes, they could be classified into identical clusters for days 1 and 2, identical clusters for day 3 to day 5, and identical clusters for day 6 to day 9. For time course analysis, we extracted 623 genes by the pairwise comparison. By using the quality threshold (QT) nonhierarchical clustering method, we identified 37 expression patterns. These patterns can be separated into eight clusters by using the k-means method. The microarray results reported here strongly suggest that a large number of genes exhibit a spike pattern, which is tantamount to phase-specific expression.

Factors influencing subclinical atherosclerosis in patients with biopsy-proven nonalcoholic fatty liver disease.

Although the presence of nonalcoholic fatty liver disease (NAFLD) is known to be related to subclinical atherosclerosis, the relationship between the severity of NAFLD and subclinical atherosclerosis is not clear. This study aimed to clarify the factors related to subclinical arteriosclerosis, including the histopathological severity of the disease and PNPLA3 gene polymorphisms, in NAFLD patients. We measured brachial-ankle pulse wave velocity (baPWV) as an index of arterial stiffness in 153 biopsy-proven NAFLD patients. The baPWV values were significantly higher in the advanced fibrosis group than in the less advanced group (median, 1679 cm/s vs 1489 cm/s; p = 5.49×10-4). Multiple logistic regression analysis revealed that older age (≥55 years) (p = 8.57×10-3; OR = 3.03), hypertension (p = 1.05×10-3; OR = 3.46), and advanced fibrosis (p = 9.22×10-3; OR = 2.94) were independently linked to baPWV ≥1600 cm/s. NAFLD patients were categorized into low-risk group (number of risk factors = 0), intermediate-risk group (= 1), and high-risk group (≥2) based on their risk factors, including older age, hypertension, and biopsy-confirmed advanced fibrosis. The prevalence of baPWV ≥1600 cm/s was 7.1% (3/42) in the low-risk group, 30.8% (12/39) in the intermediate-risk group, and 63.9% (46/72) in the high-risk group. Non-invasive liver fibrosis markers and scores, including the FIB-4 index, NAFLD fibrosis score, hyaluronic acid, Wisteria floribunda agglutinin positive Mac-2-binding protein, and type IV collagen 7s, were feasible substitutes for invasive liver biopsy. Older age, hypertension, and advanced fibrosis are independently related to arterial stiffness, and a combination of these three factors may predict risk of arteriosclerosis in NAFLD patients.

Association of vitamin D levels and vitamin D-related gene polymorphisms with liver fibrosis in patients with biopsy-proven nonalcoholic fatty liver disease.

BACKGROUND: Vitamin D has promising anti-proliferative and anti-fibrotic properties, but its clinical utility in nonalcoholic fatty liver disease (NAFLD) is unclear. AIMS: This study aimed to clarify the association between vitamin D levels, single nucleotide polymorphisms (SNPs) in vitamin D-related genes, and the histopathological severity of disease in patients with biopsy-proven NAFLD. METHODS: SNPs in CYP2R1, DHCR7, vitamin D binding protein (GC), CYP27B1, and vitamin D receptor (VDR) were determined for 229 consecutive patients with biopsy-proven NAFLD. RESULTS: In this study, vitamin D deficiency defined as 25-hydroxyvitamin-D3 levels of ≤20 ng/mL was found in 151 patients (65.9%). Multivariate analysis revealed that cold season, advanced fibrosis, and CYP2R1 rs1993116 genotype non-AA were independent factors significantly associated with vitamin D deficiency. Old age (p = 5.05 × 10-8), high body mass index (p = 2.13 × 10-2), low total-cholesterol (p = 1.46 × 10-4), low serum vitamin D level (p = 7.34 × 10-3), and VDR rs1544410 genotype CC (p = 9.15 × 10-3) were independent factors associated with advanced liver fibrosis. CONCLUSION: Serum 25-hydroxyvitamin-D3 levels and the VDR gene SNP were significantly and independently associated with the severity of liver fibrosis in patients with biopsy-proven NAFLD.

Comparison of metastatic brain tumour models using three different methods: the morphological role of the pia mater.

As methods of cancer diagnosis and treatment progress, interest in metastatic brain tumours continues to increase. There are many studies using various methods of animal model and we considered that each model reflects different pathological processes because of the unique composition of the brain. We prepared metastatic brain tumour models using three different methods. In this study, we attempted to elucidate the roles of the pia mater in brain metastasis. The metastatic foci showed an angiocentric pattern, forming collars of neoplastic cells, and were designated 'perivascular proliferations'. Furthermore, we observed neoplastic cells that infiltrated the brain parenchyma, the border of which had become indistinct. These were labelled 'invasive proliferations'. The internal carotid artery injection model reflects haematogenous metastasis. In this model, both perivascular and invasive proliferations were observed. The intrathecal injection model reflects leptomeningeal carcinomatosis. In this model, metastasis to the meninges was observed. In the stereotactic injection model, the tumour proliferation at the injection site and the infiltration into the brain parenchyma were observed. The pia-glial membrane serves as a scaffold when neoplastic cells spread to the perivascular space forming angiocentric pattern. The pia-glial membrane is found between the brain parenchyma and blood vessels. Blood vessels penetrate the brain through tunnels known as perivascular spaces that are covered by pia mater. Three different methods which we prepared reflect three different pathological processes. Our findings suggest that the pia mater is a critical factor in brain metastasis.

[Pathophysiology of invasive fungal infection in diabetic patients].

It has been known that diabetes mellitus impairs functioning of neutrophil, macrophage, cellular immunity, humoral immunity, and iron metabolism. In addition to them, diabetes-related angiopathy leads a patient to being at high-risk individual for several kinds of infectious diseases. Therefore, diabetes has been accepted as one of the important risk factors for invasive fungal infection. From the viewpoint of pathology, the present review describes both pathophysiology of immunosuppression induced by diabetes and histopathological characteristics of typical forms in invasive fungal infection when it occurred as an opportunistic infection; those are candidiasis, aspergillosis, and cryptococcosis. We wish to draw that pathophysiological explanation still remains obscuring of relationship between diabetes and invasive fungal infection.

An 8-Year-Old Girl with Autoimmune Hepatitis Following Aplastic Anemia.

We herein report a case of severe aplastic anemia diagnosed in an 8-year-old girl with a previous diagnosis of autoimmune hepatitis. We found significantly increased CD8+ and CD68+ cell numbers in her bone marrow, which can induce severe organ damage, refractory to immunosuppressive therapy.

A case of concomitant occurrence of struma ovarii and malignant transformation of cystic teratoma.

A 77-year-old woman received a total abdominal hysterectomy and bilateral salpingo-oophorectomy because of a tumor in the left ovary. The surgical specimen measured 8.5x4.5x4.0 cm, and the solid lesion measured 4.0x3.5x3.5 cm. The solid lesion was diagnosed as struma ovarii. The cyst wall partially comprised squamous epithelium-like and ciliated columnar epithelium-like cells. The tumorous lesion of the cyst wall revealed a poorly differentiated adenocarcinoma. Immunohistochemically, the tumor cells were positive for cytokeratin7, and were negative for cytokeratin20 and thyroid transcription factor-1. The authors diagnosed that struma ovarii and other parats coexisted as a poorly differentiated adenocarcinoma that had arisen from a mature ovarian cystic teratoma. As for the identification of the origin of adenocarcinomas arising from mature ovarian cystic teratomas, more cases need to be identified and investigated.

Laparoscopic Excision of a Uterine Adenomatoid Tumor and a Coexisting Ovarian Teratoma: A Case Report and Literature Review.

Adenomatoid tumors (ATs) are rare, benign neoplasms occurring mainly in reproductive organs such as the uterus, ovaries, fallopian tubes, and testes. Uterine adenomatoid tumors (UATs) are generally incidentally diagnosed during histopathological examination of excisional biopsies performed for other indications, most commonly uterine leiomyomas. We herein present a 38-year-old woman who underwent laparoscopic excision of a uterine leiomyoma and a right ovarian teratoma. Microscopic examination of the excisional biopsy revealed that the enucleated uterine tumor was composed of proliferating glandular tissue covered with single-layered cells that were surrounded by proliferating smooth muscle cells, corresponding exactly to the features of UATs. The excised ovarian cyst was confirmed to be a typical mature cystic teratoma. According to these histopathological findings, the patient was finally diagnosed with a UAT and coexisting teratoma. No recurrence was detected up to 6 months after excision. To the best of our knowledge, this is the eighth case report on laparoscopically enucleated UATs. Although recurrence risk may be low in UATs, further case reports are necessary to elucidate the safety and validity of laparoscopic excision for UATs.

Localized pulmonary crystal-storing histiocytosis complicating pulmonary mucosa-associated lymphoid tissue lymphoma presenting with multiple mass lesions.

Crystal-storing histiocytosis (CSH) is an uncommon finding in lymphoplasmacytic disorders that presents histiocytes with abnormal intralysosomal accumulations of immunoglobulin light chains as crystals of unknown etiology. A 38-year-old woman with antiphospholipid syndrome had a surgical lung biopsy because of multiple lung mass lesions. In a right middle lobe lesion, lymphoplasmacytic cells had a monocytoid appearance, destructive lymphoepithelial lesions, and positive immunoglobulin heavy chain (IGH) gene rearrangements. A right upper lobe lesion manifested proliferating rounded histiocytes with abundant, deeply eosinophilic cytoplasm and negative IGH gene rearrangements. Electron microscopy and mass spectrometry revealed a case of pulmonary CSH: abnormal proliferation of the immunoglobulin κ chain of a variable region that may be crystallized within plasma cells and histiocytes. We report a rare case of localized pulmonary CSH complicating pulmonary mucosa-associated lymphoid tissue lymphoma with multiple mass lesions. We demonstrate advances in the understanding of the pathogenesis of CSH by various analyses of these lesions.

Catalases of Aspergillus fumigatus and inflammation in aspergillosis.

The article describes various features of aspergillosis and a discussed the role of calatases produced by Aspergillus fumigatus during infection. Since a large body of invasive Aspergillus infection occurs as an opportunistic infection in variously impaired defense mechanisms, there is a wide spectrum of histopathological features of lesions demonstrated at the site of infection. Accordingly, histopathology of the lesions can be understood as a phenotypical representation of interaction between differently impaired functions of neutrophils and macrophages and virulence factors of invading Aspergilli. Consideration of previous pathological knowledge regarding infection and inflammation provides much important information to predict the pathophysiology of a patient. Meanwhile, detoxification of hydrogen peroxide by catalases has been proposed as a way to overcome this host response. A. fumigatus produces three active catalases, one from conidia and two from mycelia. CatAp, a spore specific monofunctional catalase, is resistant to heat and metal ions. In spite of their increased sensitivity to H(2)O(2), killing of catA conidia by alveolar macrophages, virulence in animals was similar to wild type conidia. In contrast to mycelial Cat1p, and CatAp catalases, the mycelial Cat2p is a bifunctional catalase-peroxidase enzyme and is also sensitive to heat, metal ions and detergent. Surprisingly, the mycelium of the double cat1 cat2 mutant with no catalase activity has only a slightly increased sensitivity to H(2)O(2) and was as sensitive to the killing of polymorphonuclear neutrophils as the wild type strain. However, it showed a delayed infection in the rat model of aspergillosis compared to the wild type strain. Consequently, it should be emphasized that conidial catalase is not a virulence factor but that mycelial catalases transiently protect the fungus from the host defence reactions.

Cellular kinetics and K-ras codon 12 mutations according to histomorphometric type of colorectal polyps with epithelial serrated proliferation.

Recent studies have examined cellular kinetics and genetic abnormalities in colorectal polyps with epithelial serrated proliferation (CP-ESP), including hyperplastic polyps, serrated adenomas, and tubulovillous adenomas. However, difficulty in histologically classifying these lesions and the lack of clear-cut diagnostic criteria have led to inconsistent findings. Some 60 cases of CP-ESP and 6 cases of CP-ESP with malignant transformation were studied. When nuclear size progressively decreased from the bottom and middle layers to the surface layer of the crypts, maturation gradient was considered positive. CP-ESP and CP-ESP adjacent to carcinoma were morphologically classified as being positive or negative for maturation gradient and inferior and lateral glandular branching. Cellular kinetics were evaluated using Ki-67 immunostaining, and polymerase chain reaction (PCR)-dependent preferential homoduplex formation assay was performed to detect the presence or absence of K-ras codon 12-point mutations. CP-ESPs were morphologically classified into five types. In CP-ESP of types 1 to 4, the proliferation zone was confined to the bottom layer of the crypts or extended from the bottom to middle layers. In contrast, the proliferation zone extended throughout the crypts in most type 5 lesions. K-ras codon 12 mutations were detected in only types 3 and 5 CP-ESP. The five histomorphologic types of CP-ESP have distinct patterns of cellular kinetics. Histomorphologically, type 3 CP-ESP is considered an atypical hyperplastic polyp, occasionally associated with an elongated proliferation zone or K-ras mutations. Preliminary evidence indicates some relation between K-ras mutations and structural atypia associated with lateral branching of the crypts.

The microvasculature of the cerebral white matter: arteries of the subcortical white matter.

The microvascular architecture of the human cerebral subcortical white matter was studied. Most of the subcortical arteries ran straight through the cortex, but upon entering the white matter, they began to coil, loop, and spiral. Vascular stains showed wide spaces between the adventitial sheaths and blood vessels. The blood vessels coiled, looped, and spiraled within these wide adventitial spaces. This phenomenon was observed in the brains from persons ranging from the first to ninth decades of life and there were no statistically significant age-related correlations. Furthermore, there was no evidence of a reduction in the volume of white matter after fixation. Therefore, the observed tortuosity does not appear to be the result of shrinkage of brain tissue following fixation. While the mechanisms responsible for the subcortical arteries circuitry remain undetermined, this coiling architecture may serve as a trap for tumor cells and microorganisms passing through the blood stream, suggesting that these coiling arterial blood vessels may play a significant role in the pathogenesis of tumor metastasis and the brain abscess that frequently occurs in the gray-white matter junction.