US-guided percutaneous biopsy: use of a screw biopsy stylet to aid needle detection

Insertion of a screw biopsy stylet into a thin-walled biopsy needle greatly enhances detection of the needle during ultrasound-guided percutaneous biopsy. This technique is helpful when precise needle-tip localization is needed for biopsies of small lesions.     

Regenerative medicine as applied to solid organ transplantation: current status and future challenges

In the last two decades, regenerative medicine has shown the potential for “bench‐to‐bedside” translational research in specific clinical settings. Progress made in cell and stem cell biology, material sciences and tissue engineering enabled researchers to develop cutting‐edge technology which has lead to the creation of nonmodular tissue constructs such as skin, bladders, vessels and upper airways. In all cases, autologous cells were seeded on either artificial or natural supporting scaffolds. However, such constructs were implanted without the reconstruction of the vascular supply, and the nutrients and oxygen were supplied by diffusion from adjacent tissues. Engineering of modular organs (namely, organs organized in functioning units referred to as modules and requiring the reconstruction of the vascular supply) is more complex and challenging. Models of functioning hearts and livers have been engineered using “natural tissue” scaffolds and efforts are underway to produce kidneys, pancreata and small intestine. Creation of custom‐made bioengineered organs, where the cellular component is exquisitely autologous and have an internal vascular network, will theoretically overcome the two major hurdles in transplantation, namely the shortage of organs and the toxicity deriving from lifelong immunosuppression. This review describes recent advances in the engineering of several key tissues and organs.     

Erythropoietin production in a primary culture of human renal carcinoma cells maintained in nude mice

The present studies report erythropoietin (Ep) production in primary cultures of a human renal carcinoma from a patient with erythrocytosis that has been serially transplanted to BALB/c nude mice. The levels of erythropoietin in the culture media were estimated using the exhypoxic polycythemic mouse assay (EHPCMA), fetal mouse liver erythroid colony- forming technique (FMLC), and a radioimmunoassay (RIA). The spent culture media of the exponentially growing cells contained less than 10 mU/ml of Ep measured by RIA. However, after the cells became confluent, Ep levels (RIA) in the spent media showed a marked increase to approximately 300 mU/ml. Ep levels estimated using the FMLC and EHPCMA were approximately 2/3 and 1/10, respectively, of those measured by RIA. Rabbit antiserum to highly purified human urinary Ep (70,400 U/mg protein) was utilized for immunocytochemical (peroxidase-antiperoxidase method) localization of Ep in the cultured cells. Very few of the cells in exponential growth exhibited Ep-like immunoreactivity, whereas intense Ep-like immunoreactivity was observed in the cytoplasm of the cells maintained in culture for a prolonged period after reaching confluency. The most intense staining was observed in some of the cells forming domes. The domes developed after the cells reached confluency, and their numbers increased with increasing time in confluent culture, in parallel with the increase in Ep levels in the spent media. This primary cell culture system of a renal cell carcinoma maintained in nude mice, which produces immunologically and biologically active Ep, may provide a useful model for studies of the mechanism of Ep production.     

Short-Ti inversion-recovery pulse sequence: analysis and initial experience in cancer imaging

Inversion recovery (IR), commonly considered a pulse sequence capable of producing T1-weighted images with excellent display of normal anatomy, is versatile: The null point and peak time provide a useful, succinct summary of the properties of IR and its capacity for producing both T1- and T2-weighted images. Shortening of the inversion time (TI) and creation of a short-TI inversion-recovery (STIR) pulse sequence increases sensitivity to malignancy and other abnormalities by making the effects of prolonged T1 and T2 on signal intensity additive and by nulling the signal from fat. The authors examined over 300 patients with various malignancies and compared STIR images with T1- and T2-weighted images obtained at 0.5 T. In 43 cases, signal-difference-to-noise ratios (SD/Ns) were calculated between tumor, fat, and muscle. In general, STIR images demonstrated tumor as a conspicuously high-intensity area in a background of muted, discernible anatomic detail. The good contrast achieved with STIR sequences between tumor and fat (SD/N = 18.1) and tumor and muscle (SD/N = 12.9) consolidated into a single image the information contained separately on T1- and T2-weighted images, which facilitates efficient detection and localization of malignancy.     

Radiological lumbar stenosis severity predicts worsening sagittal malalignment on full-body standing stereoradiographs

Background Context

Patients with degenerative lumbar stenosis (DLS) adopt a forward flexed posture in an attempt to decompress neural elements. The relationship between sagittal alignment and severity of lumbar stenosis has not previously been studied.

Aspirin in coronary artery surgery: 1-year results of the Aspirin and Tranexamic Acid for Coronary Artery Surgery trial

Background

Aspirin may reduce the risk of vascular graft thrombosis after cardiovascular surgery. We previously reported the 30-day results of a trial evaluating aspirin use before coronary artery surgery. Here we report the 1-year outcomes evaluating late thrombotic events and disability-free survival.

Semi‐xenotransplantation: the regenerative medicine‐based approach to immunosuppression‐free transplantation and to meet the organ demand

Although xenografts have always held immeasurable potential as an inexhaustible source of donor organs, immunological barriers and physiological incompatibility have proved to be formidable obstacles to clinical utility. An exciting, new regenerative medicine‐based approach termed “semi‐xenotransplantation” (SX) seeks to overcome these obstacles by combining the availability and reproducibility of animal organs with the biocompatibility and functionality of human allografts. Compared to conventional xenotransplantation wherein the whole organ is animal‐derived, SX grafts are cleansed of their antigenic cellular compartment to produce whole‐organ extracellular matrix scaffolds that retain their innate structure and vascular channels. These scaffolds are then repopulated with recipient or donor human stem cells to generate biocompatible semi‐xenografts with the structure and function of native human organs. While numerous hurdles must be still overcome in order for SX to become a viable treatment option for end‐stage organ failure, the immense potential of SX for meeting the urgent needs for a new source of organs and immunosuppression‐free transplantation justifies the interest that the transplant community is committing to the field.