超强力胶眼部损伤的研究进展

该研究旨在对超强力胶可能对眼部造成的损伤问题进行回顾。本文对以往有关强力胶有害影响的文献进行了系统的研究。在过去的30年中,超强力胶对眼部的损伤问题是很常见的,其中大多数是意外事件,虽然它对眼部组织具有毒性,但通过安全教育可以进行预防。本文阐述了眼部超强力胶损伤的处理方法,指出了预防眼部超强力胶损伤的重要性。     

Zinc Protoporphyrin Polymeric Nanoparticles: Potent Heme Oxygenase Inhibitor for Cancer Therapy

Purpose

Oxidation therapy is an antitumor strategy in which, apoptosis or necrosis is caused by either excess delivery of reactive oxygen species (ROS) as an oxidant or anti-oxidant inhibition. Heme oxygenase (HO) is an anti-oxidant enzyme that plays an important role in cell growth and proliferation. The purpose of this study was to prepare poly lactic-co-glycolic acid (PLGA) nanoparticles (NPs) loaded with zinc protoporphyrin (ZnPP) to deliver the HO inhibitor into tumor.

Methods

PLGA NPs were prepared using nanoprecipitation technique and their characteristics were optimized by Box-Behnken experimental design. Scanning electron microscopy and in vitro studies consisting of drug release, HO inhibitory effect, cytotoxicity and cellular uptake followed by in vivo biodistribution and blood cytotoxicity were carried out. Internalization of coumerin-6 loaded NPs by PC3 cells was visualized by confocal laser scanning microscopy beside quantitatively analysis.

Results

NPs average size, entrapment efficiency and drug loading were 100.12?±?5.345 nm, 55.6%?±?2.49 and 7.98%?±?0.341 respectively. Equal HO inhibitory effect of NPs compared to free ZnPP was observed. The IC₅₀ value of ZnPP-NPs for PC3 human prostate cancer cells was found to be 2.14?±?0.083 μM.

Conclusion

In conclusion, ZnPP loaded PLGA NPs could exhibit enough HO inhibitory effect against cancer cells to be considered as a promising candidate for cancer treatment investigation.     

Ascorbic Acid Reduces the Adverse Effects of Delayed Administration of Tissue Plasminogen Activator in a Rat Stroke Model

Delayed treatment of stroke with recombinant tissue plasminogen activator (r‐tPA) induces overexpression of matrix metalloproteinase 9 (MMP‐9) which leads to breakdown of the blood–brain barrier (BBB) and causes more injuries to the brain parenchyma. In this study, the effect of ascorbic acid (AA), an antioxidant agent, on the delayed administration of r‐tPA in a rat model of permanent middle cerebral artery occlusion (MCAO) was investigated. Forty male rats were randomly divided into four groups: untreated control rats (ischaemic animals), AA‐treated (500 mg/kg; 5 hr after stroke) rats, r‐tPA‐treated (5 hr after stroke 1 mg/kg) rats and rats treated with the combination of AA and r‐tPA. Middle cerebral artery occlusion was induced by occluding the right middle cerebral artery (MCA). Infarct size, BBB, brain oedema and the levels of MMP‐9 were measured at the end of study. Neurological deficits were evaluated at 24 and 48 hr after stroke. Compared to the control or r‐tPA‐treated animals, AA alone (p < 0.001) or in combination with r‐tPA (p < 0.05) significantly decreased infarct volume. Ascorbic acid alone or r‐tPA + AA significantly reduced BBB permeability (p < 0.05), levels of MMP‐9 (p < 0.05 versus control; p < 0.01 versus r‐tPA) and brain oedema (p < 0.001) when compared to either the control or the r‐tPA‐treated animals. Latency to the removal of sticky labels from the forepaw was also significantly decreased after the administration of AA + r‐tPA (p < 0.05) at 24 or 48 hr after stroke. Based on our data, acute treatment with AA may be considered as a useful candidate to reduce the side effects of delayed application of r‐tPA in stroke therapy.     

Cationic Albumin‐Conjugated Chelating Agent as a Novel Brain Drug Delivery System in Neurodegeneration

The critical role of metal ions and in particular iron in oxidative stress and protein aggregation offers chelation therapy as a sensible pharmaceutical strategy in oxidative stress‐induced neuronal damages. In this research, we conjugated an iron‐chelating agent, deferasirox, to cationized human serum albumin molecules in order to develop a novel brain delivery system for the management of neurodegenerative disorders due to the significant role of oxidative stress‐induced neuronal injury in such diseases. Cationized albumin is known to be able to transport to brain tissue via adsorptive‐mediated transcytosis. The developed structures were molecularly characterized, and their conjugation ratio was determined. PC12 cell line was utilized to evaluate the neuroprotective features of these newly developed molecules in the presence of hydrogen peroxide neuronal damage and to identify the mechanisms behind the observed neuronal protection including apoptotic and autophagic pathways. Furthermore, a rat model of Alzheimer's disease was utilized to evaluate the impact of conjugated structures in vivo. Data analysis revealed that the conjugated species were able to hinder apoptotic cell death while enhancing autophagic process. The developed conjugated species were also able to attenuate amyloid beta‐induced learning deficits when administered peripherally.     

Cardiovascular magnetic resonance of cardiac tumors and masses

Cardiac masses diagnosis and treatment are a true challenge, although they are infrequently encountered in clinical practice. They encompass a broad set of lesions that include neoplastic (primary and secondary), non-neoplastic masses and pseudomasses. The clinical presentation of cardiac tumors is highly variable and depends on several factors such as size, location, relation with other structures and mobility. The presumptive diagnosis is made based on a preliminary non-invasive diagnostic work-up due to technical difficulties and risks associated with biopsy, which is still the diagnostic gold standard. The findings should always be interpreted in the clinical context to avoid misdiagnosis, particularly in specific conditions (e.g., infective endocarditis or thrombi). The modern multi-modality imaging techniques has a key role not only for the initial assessment and differential diagnosis but also for management and surveillance of the cardiac masses. Cardiovascular magnetic resonance (CMR) allows an optimal non-invasive localization of the lesion, providing multiplanar information on its relation to surrounding structures. Moreover, with the additional feature of tissue characterization, CMR can be highly effective to distinguish pseudomasses from masses, as well as benign from malignant lesions, with further differential diagnosis of the latter. Although histopathological assessment is important to make a definitive diagnosis, CMR plays a key role in the diagnosis of suspected cardiac masses with a great impact on patient management. This literature review aims to provide a comprehensive overview of cardiac masses, from clinical and imaging protocol to pathological findings.     

Ruptured inferior vena cava aneurysm in the setting of mural vascular malformation: A case report

Aneurysm of the inferior vena cava is a rare anomaly with a very few reported cases worldwide. We report the case of a 26-years-old man with acute severe abdominal pain and hypovolemic shock following an episode of syncope. Ultrasonography showed a fusiform aneurysmal dilation of the infra-hepatic inferior vena cava (IVC), with a large saccular portion at its posterolateral wall and mural thrombosis. Abdominal computed tomography scan revealed extension to the right renal vein and adhesion to the right kidney. The saccular aneurysm and the right kidney were resected, and anatomopathological examination revealed a cavernous hemangioma. All symptoms disappeared after surgery. This is the first reported case of symptomatic congenital saccular aneurysm of the IVC due to mural vascular malformation and with involvement of the right kidney leading to nephrectomy.