Change from transrectal to transperineal ultrasound-guided prostate biopsy under local anaesthetic eliminates sepsis as a complication.

Transrectal ultrasound-guided (TRUS) biopsy of the prostate is associated with increased risk of post-procedural sepsis with associated morbidity, mortality, re-admission to hospital, and increased healthcare costs. In the study institution, active surveillance of post-procedural infection complications is performed by clinical nurse specialists for prostate cancer under the guidance of the infection prevention and control team. To protect hospital services for acute medical admissions related to the coronavirus disease 2019 (COVID-19) pandemic, TRUS biopsy services were reduced nationally, with exceptions only for those patients at high risk of prostate cancer. In the study institution, this change prompted a complete move to transperineal (TP) prostate biopsy performed in outpatients under local anaesthetic. TP biopsies eliminated the risk of post-procedural sepsis and, consequently, sepsis-related admission while maintaining a service for prostate cancer diagnosis during the COVID-19 pandemic.

PE MIMICS: a structured approach for the emergency radiologist in the evaluation of chest pain.

Chest pain is a common reason for presentation to the emergency department. In many cases, a CTPA or CT thoracic aorta is performed during work up to assess for pulmonary embolism and aortic pathology, critical diagnoses that can be difficult to out rule clinically. However, the causes of chest pain are myriad. It is therefore crucial for the interpreting radiologist to be cognizant of other potential etiologies when interpreting these studies. The purpose of this pictorial essay is to highlight the causes of non-PE or aortic-related chest pain and provide radiologists with a structured approach to interpreting these studies, ensuring a comprehensive search strategy so that important pathologies are not missed.

Creation of a protective space between the rectum and prostate prior to prostate radiotherapy using a hydrogel spacer.

The placement of a polyethylene glycol (PEG) hydrogel spacer is a recently developed technique employed to reduce the radiation dose administered to the rectum during prostate radiotherapy. This procedure has been adopted by urologists and radiation oncologists involved in transperineal prostate biopsy and brachytherapy, and more recently by radiologists with experience in transperineal prostate procedures. Radiologists should be familiar with the product, which may be encountered on computed tomography (CT) or magnetic resonance imaging (MRI). Radiologists may wish to become involved in the delivery of this increasingly utilised procedure. This review familiarises radiologists with the technique and risks and benefits of the use of transperineal delivery of hydrogel spacers with imaging examples.

Interaction of fibrinogen with its platelet receptor. Differential effects of alpha and gamma chain fibrinogen peptides on the glycoprotein IIb-IIIa complex.

The platelet membrane glycoprotein IIb-IIIa complex (GPIIb-IIIa) recognizes peptides containing the amino acid sequence Arg-Gly-Asp, a sequence present at two locations in the alpha chain of fibrinogen. GPIIb-IIIa also interacts with peptides containing the carboxyl-terminal 10-15 residues of the fibrinogen gamma chain. We found that the alpha chain tetrapeptide, Arg-Gly-Asp-Ser (RGDS), and the gamma chain peptide, Leu-Gly-Gly-Ala-Lys-Gln-Ala-Gly-Asp-Val (LGGAKQAG-DV), each inhibited fibrinogen binding to ADP-stimulated platelets with Ki values of 15.6 +/- 2.7 and 46.2 +/- 8.2 microM, respectively. Furthermore, the inhibitory effect of the peptides was additive, indicating that they interact with GPIIb-IIIa in a mutually exclusive manner. Mutually exclusive binding suggests that either the alpha and gamma chain peptides bind to identical or overlapping sites on the GPIIb-IIIa complex or that one peptide induces a change in the complex that excludes the other. To differentiate between these possibilities, we compared the ability of RGDS and LGGAKQAGDV to inhibit the binding of fibrinogen and two GPIIb-IIIa complex-specific monoclonal antibodies, A2A9 and PAC-1, to ADP-stimulated platelets. A2A9 and PAC-1 appear to bind to different sites on GPIIb-IIIa because A2A9 binds to both stimulated and unstimulated platelets while PAC-1 only binds to stimulated platelets. RGDS specifically inhibited fibrinogen and PAC-1 binding with nearly identical Ki values of 15.6 +/- 2.7 and 20.2 +/- 3.5 microM, respectively. In contrast, LGGAKQAGDV had a differential effect on fibrinogen and PAC-1 binding, inhibiting PAC-1 binding with a Ki of 116.1 +/- 12.9 microM and fibrinogen binding with a Ki of 46.2 +/- 8.2 microM (p less than 0.005). Furthermore, while RGDS had no effect on the binding of the monoclonal antibody A2A9, LGGAKQAGDV was a partial inhibitor of A2A9 binding to activated platelets. These results suggest that the bindings sites for RGDS and LGGAKQAGDV are spatially distinct. They also suggest that ligand-induced changes in GPIIb-IIIa conformation are likely to be responsible for the mutually exclusive nature of alpha and gamma chain peptide binding.