Digital imaging of the chest

During the past several years, image acquisition in nuclear medicine, computed tomography, ultrasonography, subtraction angiography, and magnetic resonance has been by digitization. Despite these advances, research in the development of digital imaging in conventional radiography has lagged behind. Although studies with a variety of digital techniques have been carried out on several fronts, we still do not possess a method that has captured the imagination of the majority of radiologists and other physicians to a point where it could replace conventional screen-film imaging. This article reviews the current status and general principles of the technology, focusing on the four digital radiographic techniques that have shown the greatest promise - film digitization, an image intensifier - based system, photostimulable phosphor plates, and a scanned projection system. The physical aspects of each of the four systems and the clinical results that have been reported to date, as well as the advantages and disadvantages of each system, are presented.     

The constrictor knot is the best ligature

Introduction

An ideal ligature should tighten readily and remain tight. Ligature failure can be a critical complication of invasive procedures in human and veterinary surgical practice. Previous studies have tested various knots but not the constrictor knot.

Methods

A new test bench was employed to compare six ligatures using four suture materials. As tension in a ligature is not readily measured, the study employed a surrogate measurement: the force required to slide a ligature along a rod. Benchmark values tested each suture material wrapped around the rod to establish the ratio between this force and the ligature tension for each material. Each ligature was tested first during tightening and then again afterwards. The benchmark ratios were employed to calculate the tensions to evaluate which ligature and which suture material retained tension best.

Results

The model provided consistent linear relationships between the tension in the suture and the force required to pull the ligature along the rod. The constrictor knot retained tension in the ligature best (55–107% better than the next best ligature). Among the suture materials, polydioxanone had the greatest ability to retain the tension in a ligature and polyglactin the least.

Conclusions

The constrictor knot showed superior characteristics for use as a ligature, and should be introduced into teaching and clinical practice for human and veterinary surgery. The new test bench is recommended for future testing of ligatures as well as objective comparison of suture materials.     

Comparison of patient reported outcomes after Triathlon? and Kinemax Plus prostheses

INTRODUCTION

The Triathlon^® (Stryker, Kalamazoo, MI, US) total knee replacement was designed to improve patient function and survivorship. The aim of this study was to determine whether the Triathlon^® prosthesis produces better patient reported outcomes than a previous design by the same manufacturer, the Kinemax Plus.

METHODS

The outcome of 233 knees of patients with a mean age of 68 years (range: 40–80 years) who received the Kinemax Plus prosthesis were compared with the outcomes of 220 knees of patients with a mean age of 70 years (range: 42–90 years) who received the Triathlon^® prosthesis. Data were collected via postal questionnaire prior to surgery as well as at 8–12 weeks and at 1 year following surgery. Validated questionnaires were used including the WOMAC^® (Western Ontario and McMaster Universities) pain and function scales, the Knee injury and Osteoarthritis Outcome Score quality of life scale and the self-administered patient satisfaction scale.

RESULTS

This study found that patients who had the Triathlon^® prosthesis had significantly better pain relief (p<0.0001), function (p=0.028), knee related quality of life (p<0.0001) and satisfaction (p=0.0003) at three months after surgery than those who received the Kinemax Plus prosthesis. In addition, knee related quality of life (p=0.002) and satisfaction (p=0.021) were significantly higher at one year after surgery in Triathlon^® patients.

CONCLUSIONS

The findings suggest that return to function and reduction in pain may occur more quickly in patients with a Triathlon^® prosthesis than in those with the Kinemax Plus.     

Microduplication of Xp11.23p11.3 with effects on cognition,behavior, and craniofacial development

El‐Hattab AW, Bournat J, Eng PA, Wu JBS, Walker BA, Stankiewicz P, Cheung SW, Brown CW. Microduplication of Xp11.23p11.3 with effects on cognition, behavior, and craniofacial development. We report an ～1.3 Mb tandem duplication at Xp11.23p11.3 in an 11‐year‐old boy with pleasant personality, hyperactivity, learning and visual‐spatial difficulties, relative microcephaly, long face, stellate iris pattern, and periorbital fullness. This clinical presentation is milder and distinct from that of patients with partially overlapping Xp11.22p11.23 duplications which have been described in males and females with intellectual disability, language delay, autistic behaviors, and seizures. The duplicated region harbors three known X‐linked mental retardation genes: FTSJ1, ZNF81, and SYN1. Quantitative polymerase chain reaction from whole blood total RNA showed increased expression of three genes located in the duplicated region: EBP, WDR13, and ZNF81. Thus, over‐expression of genes in the interval may contribute to the observed phenotype. Many of the features seen in this patient are present in individuals with Williams‐Beuren syndrome (WBS). Interestingly, the SYN1 gene within the duplicated interval, as well as the STX1A gene, within the WBS critical region, co‐localize to presynaptic active zones, and play important roles in neurotransmitter release.     

Hydrosalpinges adversely affect markers of endometrial receptivity

While in-vitro fertilization (IVF) was initially developed in women with tubal factor infertility, recent clinical studies have suggested that the presence of hydrosalpinges lowers implantation and pregnancy rates. We postulated that these hydrosalpinges cause impaired endometrial receptivity. A total of 103 women with hydrosalpinges were prospectively evaluated, and compared with 55 infertile and 44 fertile controls. All women had endometrial biopsies during the window of implantation, analysed by conventional histological criteria, and also stained for three integrin markers of endometrial receptivity (alpha1beta1, alpha4beta1 and alpha vbeta3). Women with hydrosalpinges (cases) expressed significantly less of the alpha vbeta3 integrin compared with controls. There was no difference in expression of alpha1beta1 or alpha4beta1 among groups. A significantly greater number of cases had out of phase histology and missing alpha vbeta3 (type I defects) and absent integrin expression despite normal histological maturation (type II) defects, compared with controls. Of 20 women with impaired endometrial receptivity who were also biopsied after hydrosalpinx surgery, 70% demonstrated increased alpha vbeta3 expression. Seventy-seven percent of type I and 57% of type II defects were corrected postoperatively. Using markers of endometrial receptivity, this study demonstrates that inflammatory hydrosalpinges have an adverse effect on endometrial receptivity, which in some cases may be overcome by surgical treatment of the hydrosalpinx.      

bcl-2 transgene expression promotes survival and reduces proliferation of CD3-CD4-CD8- T cell progenitors

Proliferative expansion and apoptotic cell death play prominent roles in T cell development. The molecular control of cell cycle progression and apoptosis appear to be inter-connected since the Bcl-2 protein can inhibit apoptosis and slow cell cycle progression in cortical thymocytes and mature T cells, particularly during the transition from the quiescent state into the cell cycle. Here the impact of bcl-2 transgene expression on CD3-CD4-CD8- T cell progenitors was assessed. Bcl-2 enhanced the survival of these progenitors at all of the four major differentiation stages, CD25- CD44+ (pro-T1), CD25 + CD44+ (pro- T2), CD25 + CD44- (pro-T3) and CD25-CD44- (pro-T4). However, it reduced cell cycling and slowed turnover only in the pro-T4 subset. From an analysis of bcl-2 transgenic mice expressing a TCR transgene or bearing a mutation in the scid or rag-1 gene we conclude that Bcl-2 inhibits proliferation only of T cell progenitors that are activated via the pre- TCR, not those stimulated via c-Kit and the IL-7 receptor.