Metaplastic ossification in the cartilage of the bronchus of a patient with chronic multi-drug resistant tuberculosis: a case report

<p>Abstract</p> <p>Introduction</p> <p>Pulmonary ossification has been rarely observed in pulmonary fibrosis and in some chronic respiratory diseases such as chronic obstructive pulmonary disease. We report here a metaplastic ossification in the bronchial cartilage of a patient with multi-drug resistant tuberculosis.</p> <p>Case presentation</p> <p>We report the case of a 41-year-old Asian man from Korea with chronic multi-drug resistant tuberculosis with a rare focus of bone formation from the cartilage of a bronchus subtending an active cavity. The patient had a large multi-lobed, thick-walled cavitary tuberculosis lesion in his left upper lobe. Severe infiltration of his lymphocytes and epithelioid cells, along with some giant cells and neutrophils, was observed in the patient's bronchial wall. Desquamated bronchial epithelium and acid-fast bacilli were found inside his bronchus. A small focus of bony metaplasia was found in the cartilage of his bronchial wall. Histopathological examination confirmed calcification and showed hematopoietic cells forming in his marrow cavity.</p> <p>Conclusions</p> <p>Chronic inflammation in the lungs of our patient, caused by underlying tuberculosis, probably played a role in the development of osseous metaplasia from the associated cartilage of the bronchial wall.</p

Pediatric meningiomas in The Netherlands 1974–2010: a descriptive epidemiological case study

The purpose of this study was to review the epidemiology and the clinical, radiological, pathological, and follow-up data of all surgically treated pediatric meningiomas during the last 35 years in The Netherlands. Patients were identified in the Pathological and Anatomical Nationwide Computerized Archive database, the nationwide network and registry of histopathology and cytopathology in The Netherlands. Pediatric patients of 18 years or younger at first operation in 1974-2009 with the diagnosis meningioma were included. Clinical records, follow-up data, radiological findings, operative reports, and pathological examinations were reviewed. In total, 72 patients (39 boys) were identified. The incidence of operated meningiomas in the Dutch pediatric population is 1:1,767,715 children per year. Median age at diagnosis was 13 years (range 0-18 years). Raised intracranial pressure and seizures were the most frequent signs at presentation. Thirteen (18 %) patients had neurofibromatosis type 2 (NF2). Fifty-three (74 %) patients had a meningioma World Health Organization grade I. Total resection was achieved in 35 of 64 patients. Fifteen patients received radiotherapy postoperatively. Mean follow-up was 4.8 years (range 0-27.8 years). Three patients died as a direct result of their meningioma within 3 years. Four patients with NF2 died as a result of multiple tumors. Nineteen patients had disease progression, requiring additional treatment. Meningiomas are extremely rare in the pediatric population; 25 % of all described meningiomas show biological aggressive behavior in terms of disease progression, requiring additional treatment. The 5-year survival is 83.9 %, suggesting that the biological behavior of pediatric menigiomas is more aggressive than that of its adult counterpart

A polycystic variant of a primary intracranial leptomeningeal astrocytoma: case report and literature review

<p>Abstract</p> <p>Background</p> <p>Primary leptomeningeal astrocytomas are rare intracranial tumors. These tumors are believed to originate from cellular nests which migrate by means of aberration, ultimately settling in the leptomeningeal structure. They may occur in both solitary and diffuse forms. The literature reports only fifteen cases of solitary primary intracranial leptomeningeal astrocytomas.</p> <p>Case presentation</p> <p>The authors report the case of a seventy-eight year-old woman with a polycystic variant of a solitary primary intracranial leptomeningeal astrocytoma. The first neurological signs were seizures and aphasia. CT and MRI scans demonstrated a fronto-parietal polycystic tumor adherent to the sub arachnoid space. A left fronto-temporo-parietal craniotomy revealed a tight coalescence between the tumor and the arachnoid layer which appeared to wrap the mass entirely. Removal of the deeper solid part of the tumor resulted difficult due to the presence of both a high vascularity and a tight adherence between the tumor and the ventricular wall.</p> <p>Conclusion</p> <p>A new case of a solitary primitive intracranial leptomeningeal astrocytoma of a rare polycystic variant is reported. Clinical, surgical, pathologic and therapeutic aspects of this tumor are discussed.</p

Mechanisms of escape phenomenon of spinal cord and brainstem in human rabies

BACKGROUND: Rabies virus preferentially involves brainstem, thalamus and spinal cord in human furious and paralytic rabies beginning in the early stage of illness. Nevertheless, rabies patient remains alert until the pre-terminal phase. Weakness of extremities develops only when furious rabies patient becomes comatose; whereas peripheral nerve dysfunction is responsible for weakness in paralytic rabies. METHODS: Evidence of apoptosis and mitochondrial outer membrane permeabilization in brain and spinal cord of 10 rabies patients was examined and these findings were correlated with the presence of rabies virus antigen. RESULTS: Although apoptosis was evident in most of the regions, cytochrome c leakage was relatively absent in spinal cord of nearly all patients despite the abundant presence of rabies virus antigen. Such finding was also noted in brainstem of 5 patients. CONCLUSION: Cell death in human rabies may be delayed in spinal cord and the reticular activating system, such as brainstem, thus explaining absence of weakness due to spinal cord dysfunction and preservation of consciousness

Hypomethylation of Intragenic LINE-1 Represses Transcription in Cancer Cells through AGO2

In human cancers, the methylation of long interspersed nuclear element -1 (LINE-1 or L1) retrotransposons is reduced. This occurs within the context of genome wide hypomethylation, and although it is common, its role is poorly understood. L1s are widely distributed both inside and outside of genes, intragenic and intergenic, respectively. Interestingly, the insertion of active full-length L1 sequences into host gene introns disrupts gene expression. Here, we evaluated if intragenic L1 hypomethylation influences their host gene expression in cancer. First, we extracted data from L1base (http://l1base.molgen.mpg.de), a database containing putatively active L1 insertions, and compared intragenic and intergenic L1 characters. We found that intragenic L1 sequences have been conserved across evolutionary time with respect to transcriptional activity and CpG dinucleotide sites for mammalian DNA methylation. Then, we compared regulated mRNA levels of cells from two different experiments available from Gene Expression Omnibus (GEO), a database repository of high throughput gene expression data, (http://www.ncbi.nlm.nih.gov/geo) by chi-square. The odds ratio of down-regulated genes between demethylated normal bronchial epithelium and lung cancer was high (p<1E−27; OR = 3.14; 95% CI = 2.54–3.88), suggesting cancer genome wide hypomethylation down-regulating gene expression. Comprehensive analysis between L1 locations and gene expression showed that expression of genes containing L1s had a significantly higher likelihood to be repressed in cancer and hypomethylated normal cells. In contrast, many mRNAs derived from genes containing L1s are elevated in Argonaute 2 (AGO2 or EIF2C2)-depleted cells. Hypomethylated L1s increase L1 mRNA levels. Finally, we found that AGO2 targets intronic L1 pre-mRNA complexes and represses cancer genes. These findings represent one of the mechanisms of cancer genome wide hypomethylation altering gene expression. Hypomethylated intragenic L1s are a nuclear siRNA mediated cis-regulatory element that can repress genes. This epigenetic regulation of retrotransposons likely influences many aspects of genomic biology