Platelets as delivery vehicles for targeted enrichment of NO· to cerebral glioma for magnetic resonance imaging.

Using a magnetic resonance imaging (MRI) contrast agent, MRI has made substantial contributions to glioma diagnosis. Metal-free MRI agents, such as the nano free radical nitric oxide (NO·) micelle, can overcome the inherent toxicity of metal-based agents in certain patient populations. However, the low spatial resolution of nano NO· micelle in MRI limits its clinical development. In this study, we pretreated platelets (PLTs) and loaded them with nano NO· micelles to synthesize NO·@PLT, which can overcome the low contrast and poor in vivo stability of nitroxide-based MRI contrast agents. The PLTs can serve as potential drug carriers for targeting and delivering nano NO· micelles to gliomas and thus increase the contrast in T1-weighted imaging (T1WI) of MRI. This drug carrier system uses the unique tumor-targeting ability of PLTs and takes advantage of the high signal presentation of steady nano NO· micelles in T1WI, thereby ultimately achieving signal amplification of glioma in T1WI. With the effect of PLTs-tumor cell adhesion, NO·@PLT has per-nitroxide transverse relativities of approximately 2-fold greater than those of free NO· particles. These features allow a sufficient NO·@PLT concentration to accumulate in murine subcutaneous glioma tumors up from 5 min to 2.5 h (optimum at 1.5 h) after systemic administration. This results in MRI contrast comparable to that of metal-based agents. This study established a promising metal-free MRI contrast agent, NO·@PLT, for glioma diagnosis, because it has superior spatial resolution owing to its high glioma-targeting ability and has significant translational implications in the clinic.

Role of Pre-Operative Nutrition Status on Surgical Site Infection After Posterior Lumbar Interbody Fusion: A Retrospective Study.

Background: A retrospective case-control study to determine the role of pre-operative systemic and local nutritional factors on patients developing a surgical site infection (SSI) after posterior lumbar interbody fusion (PLIF). Surgical site infection after PLIF remains a substantial cause of morbidity. The literature demonstrates the prognosis of surgical patients is associated with pre-operative nutritional status that not only includes systemic nutritional factors, such as prognostic nutritional index (PNI), body mass index (BMI), and serum albumin, but also local nutritional factors, such as subcutaneous fat thickness at the surgical site, including absolute fat thickness and relative fat thickness. However, the role of pre-operative nutrition status in SSI after PLIF surgery remains unclear. Patients and Method: A retrospective review was performed on a consecutive cohort of 766 consecutive adult patients who underwent PLIF surgery for lumbar degenerative conditions between 2020 and 2021 at Second Xiangya Hospital. Previously identified risk factors as well as systemic and local nutritional factors nutritional factors were collected. Results: Among the 766 patients, 38 had post-operative SSI including 15 superficial SSI and 23 deep SSI. Univariable analysis showed that body weight, BMI, PNI, serum albumin, and relative fat thickness differed between the SSI and non-SSI groups. Multivariable logistic regression analysis showed that pre-operative PNI and relative fat thickness were independently associated with SSI after PLIF surgery. Conclusions: Lower pre-operative PNI and higher relative fat thickness are independent risk factors for developing deep SSI after PLIF.

The role of CD4+ T cells in tumor and chronic viral immune responses.

Immunotherapies are mainly aimed to promote a CD8+ T cell response rather than a CD4+ T cell response as cytotoxic T lymphocytes (CTLs) can directly kill target cells. Recently, CD4+ T cells have received more attention due to their diverse roles in tumors and chronic viral infections. In antitumor and antichronic viral responses, CD4+ T cells relay help signals through dendritic cells to indirectly regulate CD8+ T cell response, interact with B cells or macrophages to indirectly modulate humoral immunity or macrophage polarization, and inhibit tumor blood vessel formation. Additionally, CD4+ T cells can also exhibit direct cytotoxicity toward target cells. However, regulatory T cells exhibit immunosuppression and CD4+ T cells become exhausted, which promote tumor progression and chronic viral persistence. Finally, we also outline immunotherapies based on CD4+ T cells, including adoptive cell transfer, vaccines, and immune checkpoint blockade. Overall, this review summarizes diverse roles of CD4+ T cells in the antitumor or protumor and chronic viral responses, and also highlights the immunotherapies based on CD4+ T cells, giving a better understanding of their roles in tumors and chronic viral infections.