Malignant pleural mesothelioma with heterologous elements.

AIMS: Malignant pleural mesothelioma with heterologous elements (such as osseous, cartilaginous or rhabdomyoblastic differentiation) is very rare. We tried to differentiate such mesothelioma cases from extraskeletal pleural osteosarcoma, which is very challenging. METHODS: We compared 10 malignant pleural mesotheliomas (three biphasic and seven sarcomatoid types) with two pleural osteosarcomas using clinicopathological and immunohistochemical methods, and also fluorescence in situ hybridisation (FISH) to examine for homozygous deletion of p16. RESULTS: The median age was 72 years for mesotheliomas, and 69 years for osteosarcoma. For mesothelioma, eight cases were male and two were female. Growth was diffuse in all mesothelioma cases except case 10, where it was localised, as it was for the two osteosarcomas. Among mesothelioma cases, 80% displayed osteosarcomatous and 60% chondromatous elements, while 10% exhibited rhabdomyoblastic ones. Immunohistochemical labelling for calretinin and AE1/AE3 was present in 8/10 and 7/10 mesotheliomas, respectively, but in only one osteosarcoma. Loss of methylthioadenosine phosphorylase was seen in 5/7 mesotheliomas. FISH analysis revealed homozygous deletion of p16 in 5/8 mesothelioma and 2/2 osteosarcoma. Median survival was 6.5 months after biopsy or surgical operation in mesothelioma, and 12 months after operation in osteosarcoma. CONCLUSIONS: Although median survival was longer for osteosarcoma than for malignant mesothelioma, we could not differentiate mesothelioma from pleural osteosarcoma on the combined basis of clinicopathological and immunohistochemical data, and FISH analysis. However, diffuse growth was more frequent in mesothelioma than in osteosarcoma.

Toxic shock syndrome caused by suture abscess with methicillin-resistant Staphylococcus aureus (MRSA) with late onset after Caesarean section.

Toxic shock syndrome (TSS) is a rare but life-threatening multisystem disease known to develop in the early postoperative period after various surgery. We report a rare case in which a patient who underwent Caesarean section developed TSS caused by methicillin-resistant Staphylococcus aureus (MRSA) on the 39th postoperative day. She was treated with debridement because of the possible diagnosis of necrotizing soft tissue infections. Culture test from the resected specimen was positive for MRSA. She was diagnosed with TSS caused by suture abscess and was treated with intensive care including antimicrobials. After a good postoperative course, she was discharged on the 30th postoperative day. TSS occurring 4 weeks after operation is extremely rare, but late-onset of suture abscess is known to occur. We should becognizant of development with TSS beyond early postoperative period.

Vacuolar H+-ATPase subunit Vma1p functions as the molecular ligand in the vacuole-targeting fungicidal activity of polymyxin B.

Polymyxin B (PMB) is a cationic cyclic peptide that can selectively inhibit the growth of Gram-negative bacteria by disrupting the outer membrane permeability barrier through binding to lipopolysaccharide (LPS). Here, a fluorescent PMB derivative (PMB-Ds) was applied to visually confirm the vacuole as a direct lethal target of PMB against fungal cells, which lack LPS. PMB-Ds could be visualized in the normal rounded vacuolar membrane of Saccharomyces cerevisiae cells, suggesting the presence of a molecular ligand assisting the vacuole-targeting mobilization of the peptide in the organism. Vma1p, a cytoplasmic subunit constituent of the yeast vacuolar-type ATPase, was identified as one of the PMB-binding proteins by means of mass spectrometry. Mutant cells carrying a deletion of Vma1p but not those with deletions in two separate PMB-binding proteins were shown to be resistant to the vacuolar membrane disruptive action of PMB. Furthermore, the mutant cells were resistant to PMB lethality even when treated with PMB in combination with allicin, an allyl sulfur compound, which can selectively enhance the vacuole-targeting fungicidal activity of the peptide. In contrast, the parent cells were not made resistant to the vacuolar membrane disruptive action of PMB even if cells were pre-treated with bafilomycin A1, a specific inhibitor of the yeast vacuolar-type H+-ATPase. However, the parent cells were rendered more resistant to PMB consequent to Vma1p-GFP localization in the cytoplasm. These findings suggested a role for Vma1p in the vacuole-targeting fungicidal activity of PMB comparable to that of LPS in the outer membrane of Gram-negative bacteria.

Ascending colon cancer associated with deposited ova of Schistosoma japonicum in non-endemic area.

Some reports suggest the positive correlation between Schistosoma japonicum infection and colorectal cancer, however the sufficient evidence that supports a causal relationship between them has not been established. Japan used be an endemic area of S. japonicum infection for 40 years ago. But now all of Japan is a non-endemic area of S. japonicum infection. We report a case of ascending colon cancer associated with deposited ova of S. japonicum in non-endemic area.

Flare-Up Diverticulitis in the Terminal Ileum in Short Interval after Conservative Therapy: Report of a Case.

Diverticulitis in the terminal ileum is uncommon. Past reports suggested that conservative therapy may be feasible to treat terminal ileum diverticulitis without perforation; however, there is no consensus on the therapeutic strategy for small bowel diverticulitis. We present a 37-year-old man who was referred to our hospital for sudden onset of abdominal pain and nausea. He was diagnosed with diverticulitis in the terminal ileum by computed tomography (CT). Tazobactam/piperacillin hydrate (18 g/day) was administered. The antibiotic treatment was maintained for 7 days, and the symptoms disappeared after the treatment. Thirty-eight days after antibiotic therapy, he noticed severe abdominal pain again. He was diagnosed with diverticulitis in terminal ileum which was flare-up of inflammation. He was given antibiotic therapy again. Nine days after antibiotic therapy, laparoscopy assisted right hemicolectomy and resection of 20 cm of terminal ileum were performed. Histopathology report confirmed multiple ileal diverticulitis. He was discharged from our hospital 12 days after the surgery. Colonoscopy was performed two months after the surgery and it revealed no finding suggesting inflammatory bowel disease. Surgical treatment should be taken into account as a potential treatment option to manage the diverticulitis in the terminal ileum even though it is not perforated.

Histopathologic profiles of coronary atherosclerosis by myocardial bridge underlying myocardial infarction.

OBJECTIVE: Anatomic properties of myocardial bridge (MB) are sometimes responsible for myocardial infarction (MI) through the changes in the atherosclerosis distribution in the left ascending coronary artery (LAD). The purpose of this study was to investigate histopathologic profiles of atherosclerotic lesions resulting from the MB presence in the LAD in the MI cases. METHODS: In 150 consecutive autopsied MI hearts either with MBs [MI(+)MB(+); n = 67] or without MBs [MI(+)MB(-); n = 83] and 100 normal hearts with MBs [MI(-)MB(+)], LADs were consecutively cross-sectioned at 5-mm intervals. The most advanced intimal lesion and unstable plaque-related lesion characteristics (UPLCs) in each section were histopathologically evaluated in conjunction with the anatomic properties of the MB, such as its thickness, length, location, and MB muscle volume burden (MMV: the total volume of MB thickness multiplied by MB length). RESULTS: The MB showed a significantly greater thickness (P = 0.0090), length (P = 0.0300), and MMV (P = 0.0019) in MI(+)MB(+) than in MI(-)MB(+). Mean age of acute MI cases was significantly younger (P = 0.0227) in MI(+)MB(+) than in MI(+)MB(-). Frequency of plaque fissure/rupture in the proximal LAD was significantly higher in acute MI cases of MI(+)MB(+) than in MI(+)MB(-). UPLCs tended to be located proximally in MI(+)MB(+) and frequent 2.0 cm or more proximal to the MB entrance in MI(+)MB(+). CONCLUSION: In MI(+)MB(+), UPLCs tend to be located more proximally, and a plaque in the LAD proximal to the MB is prone to rupture, resulting in MI at younger age.

Anatomic properties of myocardial bridge predisposing to myocardial infarction.

BACKGROUND: A myocardial bridge (MB) that partially covers the course of the left anterior descending coronary artery (LAD) sometimes causes myocardial ischemia, primarily because of hemodynamic deterioration, but without atherosclerosis. However, the mechanism of occurrence of myocardial infarction (MI) as a result of an MB in patients with spontaneously developing atherosclerosis is unclear. METHODS AND RESULTS: One hundred consecutive autopsied MI hearts either with MBs [MI(+)MB(+) group; n=46] or without MBs (n=54) were obtained, as were 200 normal hearts, 100 with MBs [MI(-)MB(+) group] and 100 without MBs. By microscopy on LADs that were consecutively cross-sectioned at 5-mm intervals, the extent and distribution of LAD atherosclerosis were investigated histomorphometrically in conjunction with the anatomic properties of the MB, such as its thickness, length, and location and the MB muscle index (MB thickness multiplied by MB length), according to MI and MB status. In the MI(+)MB(+) group, the MB showed a significantly greater thickness and greater MB muscle index (P<0.05) than in the MI(-)MB(+) group. The intima-media ratio (intimal area/medial area) within 1.0 cm of the left coronary ostium was also greater (P<0.05) in the MI(+)MB(+) group than in the other groups. In addition, in the MI(+)MB(+) group, the location of the segment that exhibited the greatest intima-media ratio in the LAD proximal to the MB correlated significantly (P<0.001) with the location of the MB entrance, and furthermore, atherosclerosis progression in the LAD proximal to the MB was largest at 2.0 cm from the MB entrance. CONCLUSIONS: In the proximal LAD with an MB, MB muscle index is associated with a shift of coronary disease more proximally, an effect that may increase the risk of MI.

Ultrastructural study of neuronal and related tumors in the ventricles.

Intraventricular tumors may arise from a variety of cells in the region. There are some difficulties in diagnosing these tumors because of their histologically similar appearance. We analyzed intraventricular tumors, including central neurocytoma, oligodendroglioma, cerebral neuroblastoma, and cerebellar neuroblastoma, the neuronal characters of which were established based on their ultrastructural findings, except for oligodendroglioma. Central neurocytoma and cerebellar neuroblastoma showed synaptic formation, and cerebral neuroblastoma possessed immature neurites. Oligodendroglioma showed similar structures to that of a normal oligodendrocyte. Furthermore, we review the literature and evaluate the usefulness of analyzing ultrastructures.

Topographic study of Alzheimer's neurofibrillary changes: a personal perspective.

Argentophilic neurofibrillary tangles were described in the cerebral cortex of Alzheimer's disease and later in the pigmented neurons in the brain stem of postencephalitic parkinsonism. In 1961, wide distribution of Alzheimer's neurofibrillary tangles in the central nervous system was observed in endemic fatal neurodegenerative diseases affecting the native Chamorro population on Guam: amyotrophic lateral sclerosis and parkinsonism-dementia complex on Guam. Abundant neurofibrillary tangles were found but no senile plaques. A topographic analysis of tangles in cases in Guam and at Montefiore were published in 1962. Thereafter, Alzheimer's neurofibrillary changes were documented in various areas of the nervous system of many other diseases. This communication is a brief review of the topographic investigation of Alzheimer's neurofibrillary changes. Occurrence of tangles in various conditions seems to indicate that various pathological agents can induce tangles. On the other hand, Alzheimer's neurofibrillary tangles, in general, show a rather striking predilection to affect particular neurons in the involved regions.

Two cases of spinal meningeal melanocytoma.

Meningeal melanocytoma is a rare pigmented tumor originating from the melanocytes that generally occurs in the posterior fossa and the spinal cord. Although it is known as a relatively benign tumor, some recurrences have been reported. We report two cases of spinal meningeal melanocytoma with immunohistochemical and ultrastructural studies. In addition, we include a summary of published cases since the first case of Limas and Tio in 1972.