Melting and Recrystallization of Copper Nanoparticles Prepared by Microwave-Assisted Reduction in the Presence of Triethylenetetramine.

The small sized copper nanoparticles (Cu-NPs), prepared in the presence of triethylene tetramine (TETA) and assisted with microwave irradiation, have an extremely low melting temperature. Melting of the small sizezd Cu-NPs can be triggered by the heat generated from the e-beam irradiation during SEM and TEM image construction. The dispersed Cu atoms around the agglomerated big Cu particles can undergo recrystallization immediately due to the strong driving force of the huge temperature difference to normal melting temperature (Tm = 1085 °C). Some of the Cu-NPs with bigger sizes also recrystallize and agglomerate into dense, big particles. According to X-ray diffraction patterns, these particles can agglomerate into compact, ordered Cu crystals in less than five minutes at 60 °C. The melting and recrystallization related endothermic and exothermic phase transitions of Cu-NPs can be found from differential scanning calorimeter (DSC) thermograms and optical microscopic pictures.

MiR-338-5p promotes metastasis of colorectal cancer by inhibition of phosphatidylinositol 3-kinase, catalytic subunit type 3-mediated autophagy pathway.

BACKGROUND: In our preliminary screening, expression of miR-338-5p was found to be higher in primary colorectal cancer (CRC) with metastasis. The autophagy related gene- phosphatidylinositol 3-kinase, catalytic subunit type 3 (PIK3C3) appeared to be targeted by miR-338-5p. Here, we provide solid evidence in support of PIK3C3 involved in miR-338-5p related metastasis of CRC in vitro and in vivo. METHODS: The potential clinical relevance of miR-338-5p and its target gene was analysed on benign colorectal polyps and primary CRCs by QPCR. Mouse spleen xenograft experiment was performed to examine the importance of miR-338-5p for metastasis. FINDINGS: PIK3C3 was one of target genes of miR-338-5p. In primary CRCs, expression of miR-338-5p is positively related to tumour staging, distant metastasis and poor patient survival. Patients with higher ratios of miR-338-5p/PIK3C3 also had significantly poor overall survival, supporting their significance in the progression of CRC. Over-expression of miR-338-5p promotes CRC metastasis to the liver and lung in vivo, in which PIK3C3 was down-regulated in the metastatic tumours. In contrast, overexpression of PIK3C3 in miR-338-5p stable cells inhibited the growth of metastatic tumours. Both migration and invasion of CRC in vitro induced by miR-338-5p are mediated by suppression of PIK3C3. Using forward and reverse approaches, autophagy was proved to involve in CRC migration and invasion induced by miR-338-5p. INTERPRETATION: MiR-338-5p induces migration, invasion and metastasis of CRC in part through PIK3C3-related autophagy pathway. The miR-338-5p/PIK3C3 ratio may become a prognostic biomarker for CRC patients. FUND: NCKU Hospital, Taiwan, Ministry of Science and Technology, Taiwan.

A Rare Case of Painful Trigeminal Neuropathy Secondary to Lateral Medullary Infarct: Neuroimaging and Electrophysiological Studies.

PURPOSE: To report a rare case of painful trigeminal neuropathy after lateral medullary infarct and probe its underlying pathogenesis on the basis of neuroimaging and electrophysiological study. CASE REPORT: A 45-year-old man presented acute onset of unsteady gait followed by paroxysmal and electric shock-like headache in the distribution of ophthalmic branch of left trigeminal nerve in 2 days. Neurological examinations showed hypoesthesia in the distribution of mandibular branch of left trigeminal nerve and left appendicular ataxia. Muscle powers and deep tendon reflexes were normal. Brain magnetic resonance imaging revealed infarct within the left cerebellum and middle portion of dorsolateral medulla. Vascular compression at the root entry zone of trigeminal nerve was excluded. Painful trigeminal neuropathy secondary to lateral medullary infarct was diagnosed. Ancillary blink reflex study 3 days after the stroke event showed abnormal late responses (R2), either ipsilateral or contralateral, after stimulation of left supraorbital nerve, suggesting left medullary lesion. Followup study 3 weeks later demonstrated normalization in absolute latencies of bilateral late responses, in line with remission of pain paroxysms on low-dose gabapentin treatment. CONCLUSION: Painful trigeminal neuropathy attributed to lateral medullary infarct is a unique disease entity. Ophthalmic branch involvement, coexisting sensory deficits, absence of triggers, and rapid evolvement and remission are its characteristics. Our neuroimaging study delineated ischemic stroke pathology within descending tract and spinal nucleus of trigeminal nerve. Serial electrophysiological studies provide evidences supporting ephaptic transmission as the main pathogenesis concordant with dynamics of neuropathic pain and therapeutic implications.

A case of dermatomyositis with secondary Sjögren's Syndrome-diagnosis with follow-up study of technetium-99m pyrophosphate scintigraphy.

PURPOSE: To report a case of dermatomyositis (DM) with secondary Sjögren's syndrome (SS) and propose the clinical application of technetium-99m pyrophosphate ((99m)Tc-PYP) scan. CASE REPORT: A 50-year-old woman had progressive proximal muscle weakness of bilateral thighs, myalgia, tea-colored urine, and exercise intolerance for 6 months. Physical examination showed malar rash, V-sign, periungual erythema, and mechanic hands. Neurological assessment showed symmetric pelvic-girdle weakness, myopathic face, waddling gait, but preserved deep tendon reflex and sensory functions. DM was diagnosed on the basis of typical rashes and serum creatinine kinase elevation (7397 IU/L). Aside from myopathic symptoms, dry eye and mouth were reported. Thorough autoantibody searches showed positive anti-SSA/Ro antibody (198 U/ml). Both Schirmer's test and sialoscintigraphy were positive, leading secondary SS as diagnosis. Initial (99m)Tc-PYP scan revealed increased radiouptake in the muscles of bilateral thighs, compatible with clinical assessment. Followup scan three months later shows abnormal but attenuated radiouptake at bilateral thighs, in the presence of nearly-complete clinical recovery. CONCLUSION: DM with secondary SS in adult is a unique disease entity, with predominantly myopathic symptoms and satisfactory therapeutic response as its characteristics. Our serial muscle imaging studies suggest that (99m)Tc-PYP scan is at once anatomically-specific and persistently-sensitive to microstructural damages within inflammatory muscles, enabling clinician to monitor disease activity and therapeutic response.