Systemically injected exosomes targeted to EGFR deliver antitumor microRNA to breast cancer cells.

Despite the therapeutic potential of nucleic acid drugs, their clinical application has been limited in part by a lack of appropriate delivery systems. Exosomes or microvesicles are small endosomally derived vesicles that are secreted by a variety of cell types and tissues. Here, we show that exosomes can efficiently deliver microRNA (miRNA) to epidermal growth factor receptor (EGFR)-expressing breast cancer cells. Targeting was achieved by engineering the donor cells to express the transmembrane domain of platelet-derived growth factor receptor fused to the GE11 peptide. Intravenously injected exosomes delivered let-7a miRNA to EGFR-expressing xenograft breast cancer tissue in RAG2(-/-) mice. Our results suggest that exosomes can be used therapeutically to target EGFR-expressing cancerous tissues with nucleic acid drugs.

Visual functional and histopathological correlation in experimental autoimmune optic neuritis.

PURPOSE: To elucidate the correlation between visual threshold of optokinetic tracking (OKT), visual evoked potential (VEP), and histopathology at different time points after induction of experimental autoimmune optic neuritis (EAON). METHODS: EAON was induced in C57BL/6 mice by subcutaneous immunization with an emulsified mixture of myelin oligodendrocyte glycoprotein (MOG)(35-55) peptide. OKT and VEP were measured on days 7, 14, 21, 28, and 42 postimmunization. After VEP measurements, the mice were killed and their eyes were enucleated for histopathological studies. Immunohistochemical staining was performed using cell-specific markers for characterization of cells in the optic nerve: CD3 (T cells), Iba-1 (microglia), MBP (myelin basic protein), and neurofilament (axons). RESULTS: Functionally, OKT threshold decreased as early as day 7, and VEP latency was significantly prolonged on day 21. Axon degeneration was observed as early as day 14. Activated microglia infiltration was also observed on day 14, before T cell infiltration, which peaked on day 21. Demyelination, confirmed by MBP staining, was observed on day 21. CONCLUSIONS: Microglial infiltration in the optic nerve coincided with decline in OKT threshold and preceded VEP latency prolongation, while VEP latency prolongation coincided with T cell infiltration and demyelination of the optic nerve. These findings may contribute to understanding of the pathophysiology of optic neuritis and future development of more effective therapeutic strategy for refractory optic neuritis.

Cyclophilin D-sensitive mitochondrial permeability transition in adult human brain and liver mitochondria.

The mitochondrial permeability transition (mPT) is considered to be a major cause of cell death under a variety of pathophysiological conditions of the central nervous system (CNS) and other organs. Pharmacological inhibition or genetic knockout of the matrix protein cyclophilin D (CypD) prevents mPT and cell degeneration in several models of brain injury. If these findings in animal models are translatable to human disease, pharmacological inhibition of mPT offers a promising therapeutic target. The objective of this study was to validate the presence of a CypD-sensitive mPT in adult human brain and liver mitochondria. In order to perform functional characterization of human mitochondria, fresh tissue samples were obtained during hemorrhage or tumor surgery and mitochondria were rapidly isolated. Mitochondrial calcium retention capacity, a quantitative assay for mPT, was significantly increased by the CypD inhibitor cyclosporin A in both human brain and liver mitochondria, whereas thiol-reactive compounds and oxidants sensitized mitochondria to calcium-induced mPT. Brain mitochondria underwent swelling upon calcium overload, which was reversible upon calcium removal. To further explore mPT of human mitochondria, liver mitochondria were demonstrated to exhibit several classical features of the mPT phenomenon, such as calcium-induced loss of membrane potential and respiratory coupling, as well as release of the pro-apoptotic protein cytochrome c. We concluded that adult viable human brain and liver mitochondria possess an active CypD-sensitive mPT. Our findings support the rationale of CypD and mPT inhibition as pharmacological targets in acute and chronic neurodegeneration.

Immunohistochemical and ultrastructural investigation on cutaneous neuroendocrine carcinoma: report of a case and review of the literature.

We report a tumor in an 80-year-old man that was difficult to distinguish from other tumors, i.e., small cell carcinoma of the lung, PNET/Ewing tumor, malignant lymphoma, or malignant melanoma (amelanotic), and which was finally identified as cutaneous neuroendocrine carcinoma using immunohistochemical and ultrastructural methods. Autopsy did not show any tumors in the lungs, excluding the possibility of small cell carcinoma of the lung. Immunohistochemistry tests gave negative results for LCA, UCHL-1, CD3, and CD20, thereby excluding malignant lymphoma, and the negative results for S-100 protein and HMB-45 ruled out malignant melanoma. The possibility of PNET/Ewing sarcoma was also excluded because of negativity for CD99. In addition, the ultramicrostructure showed intercellular junctional complexes and neuroendocrine granules, indicating that the tumor had characteristics of both epithelial and neuroendocrine tissues. We therefore diagnosed the primary carcinoma of the skin as cutaneous neuroendocrine carcinoma.

The frequency of fingerprint type in parents of children with Trisomy 21 in Japan.

Analysis of the frequency data of each fingerprint type (arch, ulnar loop, radial loop, and whorl) of the parents of children with Trisomy 21 (Fathers: 71; Mothers: 128) born between 1965 and 1970 obtained from the Tokyo Medical and Dental University Hospital was carried out. Japanese controls were taken from dermatoglyphics data in Japan. We conducted the Friedman test on each type of fingerprint between Japanese controls and parents of Trisomy 21 children. Results from a statistical analysis based on the above data showed significant differences, more arches (p < 0.0001) and fewer whorls (p < 0.05) in mothers of children with Trisomy 21. Among fathers of Trisomy 21 children, a significant difference was found in there being fewer whorls (p < 0.05) and ulnar loops (p = 0.06). Considering the mothers' fingerprints, we suspected that females with a higher frequency of arches and a lower frequency of whorls had a stronger possibility of bearing Trisomy 21 babies. On the other hand, in fathers of Trisomy 21 children, we considered that there would be a possibility of significant differences if cases in the sample were increased.

A case of generalized hypoxic brain damage following traumatic brain damage.

In forensic autopsy cases, transient brain hypoxia can be induced by cardiac arrest, hypovolemic shock, and other conditions with severe circulatory failure. Although cortical laminar necrosis in watershed areas between territories of the major cerebral arteries is occasionally seen, cases with global hypoxic damage to the brain is rare, because patients with irreversible severe brain damage rarely survive for more than a few days. In this report we describe autopsy results for an injury victim who survived unconscious for approximately 4 weeks after admission. Macroscopic thinning of the gray matter and uniformly cheesecake-like cloudy changes in white matter were observed. Microscopically, cortical laminar necrosis was observed in all lobes of the cerebrum, and massive gliosis was diffused throughout the white matter. We speculate that traumatic brain damage, continuous hypoxemia, and many other factors induced these characteristic pathological changes during the long time interval from brain damage to death.

Toluene diisocyanate exposure induces laryngo-tracheal eosinophilia, which can be ameliorated by supplementation with antioxidant vitamins in guinea pigs.

OBJECTIVE: Toluene diisocyanate (TDI)-induced asthma is a common cause of occupational lung disease. In addition, a sore throat is one of the complaints of TDI-exposed workers. The aim of the present study was to determine whether TDI exposure induces laryngeal and/or tracheal lesions in experimental animals. MATERIAL AND METHODS: Guinea pigs underwent naris application of TDI three times, and their respiratory tracts were then examined using light and electron microscopy. Some animals simultaneously received vitamins C and E. which function as antioxidant agents. RESULTS: When TDI-treated animals showed the clinical sign of labored breathing, many eosinophils had appeared in the lamina propria and mucosa of both the larynx and trachea, which finally infiltrated the tract lumen through the ruptured epithelium. Laryngo-tracheal inflammation was more severe than that observed in the lungs. However, supplementation with antioxidant vitamins in TDI-treated animals ameliorated the respiratory eosinophilia. CONCLUSION: Naris application of TDI induced laryngotracheitis. which was significantly suppressed by the antioxidant vitamins, This implies a preventive effect of the vitamins on this occupational disease.

An autopsy case of bilateral tension pneumothorax after acupuncture.

Acupuncture is one of the most popular complementary therapies in the world. Pneumothorax due to perforation of the lungs by needle insertion is one of the most common and serious complications of acupuncture treatment. Although there have been several case studies of pneumothorax induced by acupuncture, as far as we know there have been no reports on the pathological findings of autopsy cases. In this report, we describe the pathological findings of an autopsy case of bilateral tension pneumothorax after acupuncture. The patient suffered dyspnea and chest pain soon the completion of an acupuncture treatment, and died 90 min later. Several ecchymoses were macroscopically observed on the parietal pleura in the left and right thoracic cavity, suggesting that needles were inserted into the thoracic cavity and that the lungs were perforated. The many black spots we observed on the parietal pleura along the vertebral column microscopically consisted of a number of dust-like black pigments and macrophages containing these pigments. These spots seemed to have appeared because of the previous insertion of needles.