Discordant Electrocardiogram Left Ventricular Wall Thickness and Strain Findings in Influenza Myocarditis

A 42‐year‐old man presented with a viral prodrome and tested positive for influenza A. He rapidly deteriorated developing cardiogenic shock, rhabdomyolysis, and acute kidney injury. Patient improved 1 week later with supportive measures including vasopressors, inotropes, and an intraaortic balloon pump. We report this case as it highlights the discordance between echocardiographic ventricular wall thickening as a result of myocardial edema, and electrocardiographic findings at presentation, with a reversal in findings at time of resolution. Additionally, there was some suggestion of a regional pattern to the reduced longitudinal strain.     

Screw angulation affects bone-screw stresses and bone graft load sharing in anterior cervical corpectomy fusion with a rigid screw-plate construct: a finite element model study

Background contextAnterior corpectomy and reconstruction with bone graft and a rigid screw-plate construct is an established procedure for treatment of cervical neural compression. Despite its reliability in relieving symptoms, there is a high rate of construct failure, especially in multilevel cases.PurposeThere has been no study evaluating the biomechanical effects of screw angulation on construct stability; this study investigates the C4–C7 construct stability and load-sharing properties among varying screw angulations in a rigid plate-screw construct.Study designA finite element model of a two-level cervical corpectomy with static anterior cervical plate.MethodsA three-dimensional finite element (FE) model of an intact C3–T1 segment was developed and validated. From this intact model, a fusion model (two-level [C5, C6] anterior corpectomy) was developed and validated. After corpectomy, allograft interbody fusion with a rigid anterior screw-plate construct was created from C4 to C7. Five additional FE models were developed from the fusion model corresponding to five different combinations of screw angulations within the vertebral bodies (C4, C7): (0°, 0°), (5°, 5°), (10°, 10°), (15°, 15°), and (15°, 0°). The fifth fusion model was termed as a hybrid fusion model.ResultsThe stability of a two-level corpectomy reconstruction is not dependent on the position of the screws. Despite the locked screw-plate interface, some degree of load sharing is transmitted to the graft. The load seen by the graft and the shear stress at the bone-screw junction is dependent on the angle of the screws with respect to the end plate. Higher stresses are seen at more divergent angles, particularly at the lower level of the construct.ConclusionThis study suggests that screw divergence from the end plates not only increases load transmission to the graft but also predisposes the screws to higher shear forces after corpectomy reconstruction. In particular, the inferior screw demonstrated larger stress than the upper-level screws. In the proposed hybrid fusion model, lower stresses on the bone graft, end plates, and bone-screw interface were recorded, inferring lower construct failure (end-plate fractures and screw pullout) potential at the inferior construct end.     

Thermal and cold neutron phase-contrast radiography.

In this paper, we will discuss a phase-contrast imaging method that avoids the complications of interferometry to provide phase contrast in weakly absorbing samples. A transversely coherent neutron beam is used with the traditional radiography scheme. Images taken with this scheme show dramatic intensity variations due to sharp changes in the neutron wave refractive index. With some numerical processing these images may be used to reconstruct a quantitative phase radiograph of specimens imaged with this technique.     

High prevalence of and risk factors for hepatitis C in haemodialysis patients in Saudi Arabia: a need for new dialysis strategies

Non-A, non-B is a major form of hepatitis in haemodialysis (HD)patients. Hepatitis C virus (HCV) has been recently identifiedas the leading cause of non-A, non-B hepatitis in HD. A variableprevalence of hepatitis in HD has appeared in the literature,ranging between 1% and 29% in the Western world, and between30% and 54% in Saudi Arabia, but all these reports used first-generationELISA. Using second-generation enzyme immunoassay, we conducteda multi-centre study involving 22 HD centres all over SaudiArabia in order to establish the prevalence and risk factorsfor HCV in HD patients in Saudi Arabia. A total of 1147 patientswere studied, with a mean age of 43.4±15.3 years. Fivehundred and eighty were males and 567 were females. The overallprevalence rate of positive anti-HCV was 68%, with a range fromas low as 14.5%, to 94.7%. To our knowledge, this is the highestvalue reported among dialysis patients world-wide. A positivecorrelation was found between anti-HCV positivity and male sex(P=0.005), longer duration on dialysis (P=0.002) and blood transfusion(P=0.003). However, interestingly 62.6% of the patients whohad not had blood transfusion had anti-HCV antibodies. HCV antibodieswere also found more frequently in Egyptians, Pakistanis andYemenis than in Saudis. A comparison between those centres withlow prevalence of positive HCV and those with high prevalenceregarding risk factors was carried out, and it was found thatthe major difference between them was the adherence of the staffto universal infection precautions. In conclusion, HCV is amajor health problem in HD patients in Saudi Arabia. Identifiablerisk factors are longer duration in dialysis, blood transfusion,male sex, nationality and most importantly the lack of adherenceto universal infection precautions.