Conditionally replicative adenovirus as a therapy for malignant peripheral nerve sheath tumors.

Oncolytic adenoviruses (Ads) stand out as a promising strategy for the targeted infection and lysis of tumor cells, with well-established clinical utility across various malignancies. This study delves into the therapeutic potential of oncolytic Ads in the context of neurofibromatosis type 1 (NF1)-associated malignant peripheral nerve sheath tumors (MPNSTs). Specifically, we evaluate conditionally replicative adenoviruses (CRAds) driven by the cyclooxygenase 2 (COX2) promoter, as selective agents against MPNSTs, demonstrating their preferential targeting of MPNST cells compared with non-malignant Schwann cell control. COX2-driven CRAds, particularly those with modified fiber-knobs exhibit superior binding affinity toward MPNST cells and demonstrate efficient and preferential replication and lysis of MPNST cells, with minimal impact on non-malignant control cells. In vivo experiments involving intratumoral CRAd injections in immunocompromised mice with human MPNST xenografts significantly extend survival and reduce tumor growth rate compared with controls. Moreover, in immunocompetent mouse models with MPNST-like allografts, CRAd injections induce a robust infiltration of CD8+ T cells into the tumor microenvironment (TME), indicating the potential to promote a pro-inflammatory response. These findings underscore oncolytic Ads as promising, selective, and minimally toxic agents for MPNST therapy, warranting further exploration.

DAZL Knockout Pigs as Recipients for Spermatogonial Stem Cell Transplantation.

Spermatogonial stem cell (SSC) transplantation into the testis of a germ cell (GC)-depleted surrogate allows transmission of donor genotype via donor-derived sperm produced by the recipient. Transplantation of gene-edited SSCs provides an approach to propagate gene-edited large animal models. DAZL is a conserved RNA-binding protein important for GC development, and DAZL knockout (KO) causes defects in GC commitment and differentiation. We characterized DAZL-KO pigs as SSC transplantation recipients. While there were GCs in 1-week-old (wko) KO, complete GC depletion was observed by 10 wko. Donor GCs were transplanted into 18 DAZL-KO recipients at 10-13 wko. At sexual maturity, semen and testes were evaluated for transplantation efficiency and spermatogenesis. Approximately 22% of recipient seminiferous tubules contained GCs, including elongated spermatids and proliferating spermatogonia. The ejaculate of 89% of recipients contained sperm, exclusively from donor origin. However, sperm concentration was lower than the wild-type range. Testicular protein expression and serum hormonal levels were comparable between DAZL-KO and wild-type. Intratesticular testosterone and Leydig cell volume were increased, and Leydig cell number decreased in transplanted DAZL-KO testis compared to wild-type. In summary, DAZL-KO pigs support donor-derived spermatogenesis following SSC transplantation, but low spermatogenic efficiency currently limits their use for the production of offspring.

Combining nonsense mutation suppression therapy with nonsense-mediated decay inhibition in neurofibromatosis type 1.

Neurofibromatosis type 1 (NF1) results from germline mutations in the tumor-suppressor gene NF1 and predisposes patients to developing nervous system tumors. Twenty percent of NF1 patients harbor nonsense mutations resulting in premature termination codons (PTCs). Nonsense suppression therapies can facilitate ribosomal readthrough of PTCs to restore full-length protein, but their potential in NF1 is underexplored. We developed a minipig model of NF1 carrying a PTC to test whether nonsense suppression could restore expression of the NF1-encoded protein neurofibromin in vitro and in vivo. Nonsense suppression did not reliably increase neurofibromin in primary NF1-/- Schwann cells isolated from minipig neurofibromas but could reduce phosphorylated ERK. Gentamicin in vivo produced a similar plasma pharmacokinetic profile to humans and was detectable in clinically relevant tissues, including cerebral cortex, sciatic nerve, optic nerve, and skin. In gentamicin-treated animals, increased neurofibromin expression was seen in the optic nerve. Nonsense-mediated decay (NMD) causes degradation of transcripts with PTCs, which could impede nonsense suppression therapies. Nonsense suppression in combination with NMD inhibition restored neurofibromin protein expression in primary NF1-/- Schwann cells isolated from minipig neurofibromas. Thus, the effectiveness of nonsense suppression therapies can be improved in NF1 by the concurrent use of NMD inhibitors.

Attached flow structure and streamwise energy spectra in a turbulent boundary layer.

On the basis of (i) particle image velocimetry data of a turbulent boundary layer with large field of view and good spatial resolution and (ii) a mathematical relation between the energy spectrum and specifically modeled flow structures, we show that the scalings of the streamwise energy spectrum E_{11}(k_{x}) in a wave-number range directly affected by the wall are determined by wall-attached eddies but are not given by the Townsend-Perry attached eddy model's prediction of these spectra, at least at the Reynolds numbers Re_{τ} considered here which are between 10^{3} and 10^{4}. Instead, we find E_{11}(k_{x})∼k_{x}^{-1-p} where p varies smoothly with distance to the wall from negative values in the buffer layer to positive values in the inertial layer. The exponent p characterizes the turbulence levels inside wall-attached streaky structures conditional on the length of these structures. A particular consequence is that the skin friction velocity is not sufficient to scale E_{11}(k_{x}) for wave numbers directly affected by the wall.

CCD camera response to diffraction patterns simulating particle images.

We present a statistical study of CCD (or CMOS) camera response to small images. Diffraction patterns simulating particle images of a size around 2-3 pixels were experimentally generated and characterized using three-point Gaussian peak fitting, currently used in particle image velocimetry (PIV) for accurate location estimation. Based on this peak-fitting technique, the bias and RMS error between locations of simulated and real images were accurately calculated by using a homemade program. The influence of the intensity variation of the simulated particle images on the response of the CCD camera was studied. The experimental results show that the accuracy of the position determination is very good and brings attention to superresolution PIV algorithms. Some tracks are proposed in the conclusion to enlarge and improve the study.

A high risk group for thoracolumbar fractures.

Unconscious patients with multiple injuries present a major diagnostic and therapeutic problem. The incidence of neurological deficit increases if diagnosis of a spinal injury is delayed or missed. Thoracolumbar fractures are commonly the result of high energy injuries and in an unconscious patient the risk of missing such fractures is increased considerably. There is little consensus on which blunt trauma patients warrant thoracolumbar spine films when no pain, tenderness, neurological deficit or cervical spine injuries are identified. We present a retrospective analysis of all patients who were admitted to the Major Injuries Unit at the Birmingham General Hospital and underwent radiological survey of the thoracolumbar spine. Of the 110 patients, all spinal fractures were detected in 94 patients with a Glasgow Coma Scale (GCS) > or = 11. Of the 16 with a GCS < or = 10, 9 patients had sustained injuries of their thoracolumbar spine 4 of which were not detected initially due to a decreased level of consciousness. The common features amongst the 4 patients with missed injuries were: (1) High velocity injury. (2) Decreased level of consciousness on admission. (3) Associated head injury. (4) Pelvis/lower extremity injury. We describe the four cases and identify a group of high risk patients for thoracolumbar fractures. Radiological examination of the thoracolumbar spine is essential in this group.

Localization of the ulnar nerve during percutaneous wiring of supracondylar fractures in children.

Injury of the ulnar nerve may occur when using percutaneous Kirschner wires (K-wires) in the treatment of supracondylar humeral fractures of the elbow especially in children whose bony landmarks are masked by swelling. We describe a technique in which this complication can be avoided during the procedure. The nerve is located first using a needle attached to a nerve stimulator. The K-wire is then inserted 0.5 to 0.75 mm anterior and parallel to the needle. Ten supracondylar fractures of the humerus were stabilized using this procedure and there were no ulnar nerve complications.

Skiing injuries: the increasing workload.

All skiing injuries presenting to a fracture clinic during the period December 1992 to April 1993 were studied. Fifty five patients with 59 injuries were treated during this period. Thirty (54.5%) were male and 25 (45.5%) female. The mean age was 34 years (range 9-61). The anatomical distribution of injuries seen corresponded very closely with those seen in much larger studies abroad. There were 35 upper limb injuries (59.3%), 22 lower limb injuries (37.3%), with only two spine and trunk injuries (3.4%). While only two patients underwent surgery abroad, a further 12 needed surgical intervention on return, requiring a total stay of 61 'inpatient days'. The bulk of the workload was, however, on an outpatient basis, with a total of 172 appointments. Many advances have been made towards improving the safety of skiing. However with skiing becoming increasingly popular we can expect an increasing workload and cost associated with such injuries.