Regional myocardial oxygen tension: 19F MRI of sequestered perfluorocarbon

A novel noninvasive method of measuring local myocardial oxygen tension (pO₂) In the perfused rat heart using ¹⁹F MRI is demonstrated. Tissue pO₂ was determined on the basis of the ¹⁹F spin-lattice relaxation rate (R1) of perflubron (perfluorooctyl bromide) sequestered in the heart after IV infusion of an emulsion. Spectroscopic measurement of R1 was previously used to measure a global weighted average of oxygen status. ¹⁹F MRI now provides 3D spatial resolution indicating local cardiac pO₂ under normally perfused, globally ischemic, and regionally ischemic conditions.     

The Cbl family of ubiquitin ligases: critical negative regulators of tyrosine kinase signaling in the immune system

The Cbl family of proteins are evolutionarily conserved negative regulators of activated tyrosine kinase-coupled receptors. Antigen receptors are prominent targets of negative regulation by the Cbl family members, Cbl and Cbl-b, which proteins function as ubiquitin ligases. Cbl and Cbl-b contain substrate recognition domains that interact specifically with activated protein tyrosine kinases of the Src and Syk/ZAP-70 families. Cbl-mediated ubiquitination of these kinases leads to their degradation, resulting in attenuation of receptor signals. Cbl may also control activation-induced monoubiquitination of antigen receptors, thus facilitating their delivery to lysosomes for subsequent degradation. Finally, the interactions of Cbl proteins with downstream targets of tyrosine kinases, such as PI-3-kinase and Vav, could provide an additional mechanism to attenuate receptor signaling. By targeting multiple components of antigen receptor signaling for degradation, the Cbl protein family provides a critical mechanism to ensure an appropriate immune response. The hyperresponsiveness of Cbl(-/-) and Cbl-b(-/-) lymphocytes and the autoimmune phenotype of Cbl-b(-/-) mice lend strong support for this proposal. The ability to control early receptor signals through regulated protein degradation provides a novel paradigm of immunoregulation.     

Is It Time to Move on from Two-Dimensional Transesophageal to Three-Dimensional Transthoracic Echocardiography for Assessment of Left Atrial Appendage? Review of Existing Literature

Left atrial appendage (LAA) has unique anatomical and physiological properties, which make it a common site for thrombus formation in many cardiovascular and systemic diseases. Assessment of LAA for thrombus thus becomes important in many clinical situations and two-dimensional transesophageal echocardiography (2D TEE), which allows excellent quality images of LAA because of its close proximity to esophagus is routinely used for this purpose. However, it is a semiinvasive procedure, requires more time and involves some degree of patient discomfort. With some training and experience, two-dimensional transthoracic echocardiography (2D TTE) can visualize LAA in most patients with good acoustic windows. A disadvantage of both 2D TTE and 2D TEE is that they provide only a thin slice or section of cardiac structures at any given time limiting their utility in comprehensively assessing the LAA for thrombus. On the other hand, live/real time three-dimensional (3D) TTE overcomes this limitation of both 2D TTE and 2D TEE because of its ability to encompass whole of the LAA in three-dimensions in the acquired data set, which can then be cropped and sectioned systematically at any desired angulation to more definitively look for clot. 3D TTE is also useful in differentiating a clot from pectinate muscles in the LAA, which can mimic a thrombus resulting in patient mismanagement. In addition, 3D TTE is helpful in sectioning a clot for lysis, which has implications in clot resolution. We reviewed the existing literature comparing the relative advantages and disadvantages of 3D TTE versus 2D TEE and found that in patients with good acoustic windows 3D TTE had similar efficacy for detecting LAA thrombus. (Echocardiography 2012;29:112-116)     

Real Time Three-Dimensional Echocardiography for the Evaluation of Cardiomyopathy

Cardiomyopathy refers to a set of diseases that are characterized by myocardial dysfunction. Classically, two-dimensional echocardiography has been used in the diagnosis of these disorders and to help guide their management. Three-dimensional transthoracic echocardiography is now increasingly being used in the diagnosis, management, and prognostication of intrinsic cardiomyopathies. In this article, we summarize the available data on the use of three-dimensional transthoracic echocardiography in various forms of intrinsic cardiomyopathy as well as some of its advantages over traditional two-dimensional transthoracic echocardiography. (Echocardiography 2012;29:76-87)     

Zidovudine for treating AIDS

For additional diagnostic clues, Dr Morris recommends looking at the eyes. Many systemic diseases, including diabetes mellitus, thyroid disease, and AIDS, have characteristic ocular manifestations. These often can be seen with tools readily available to primary care physicians. This article sheds light on the role of ocular findings in the evaluation of systemic disease.     

Custom prosthetic replacement for distal radial tumours

We analysed the results of 24 cases of aggressive benign and malignant tumours of the distal radius treated by resection and prosthetic replacement between 1995 and 2006. Patient ages ranged from 18 to 74 years, averaging 33 years; 18 were males. Recurrent giant cell tumour was the most common tumour. The prosthesis used was a bipolar hinge custom mega prosthesis manufactured locally. Average follow-up was 78 months. The average Musculoskeletal Tumor Society (MSTS) functional score achieved was 75%. The ten-year prosthesis survival was rate 87.5%. Infection was the most common complication.

---

Resume  Prothèses sur mesure dans les tumeurs du radius distal. Indications de remplacement. Nous avons analysé les résultats de 24 cas de tumeurs malignes et bégnines agressives de l’extrémité distale du radius traitées par résection et prothèses entre 1995 et 2006. Les patients étaient agées de 18 à 74 ans avec un age moyen de 33 ans dont- 18 étaient des hommes. La cause la plus fréquente a été la récidive de tumeur à cellules géantes. La prothèse utilisée était une prothèse bipolaire à charnière sur mesure fabriquée localement. Le suivi moyen a été de 78 mois. Le score moyen MSTS après traitement était de 75%, la courbe de survie à 10 ans de 87,5%. La complication la plus fréquente a été l’infection.

     

广泛性甲状腺切除治疗原发性甲状腺功能亢进

目的探讨原发性甲状腺功能亢进的手术治疗。方法回顾性分析33例原发性甲状腺功能亢进症患者手术治疗的临床资料,行双侧近全切除30例,一侧全切加对侧次全切2例,双侧全切除1例。结果本组无死亡病例,双侧全切除患者术后发生永久性喉返神经瘫痪伴甲状旁腺功能低下。所有病例经随访2-18月,无1例复发,5例出现甲状腺功能减退,采用甲状腺素替代治疗效果满意。结论手术是治疗原发性甲状腺功能亢进的安全有效办法,推荐术式为甲状腺近全切除术,强调围手术期处理,熟练掌握手术技巧可防止手术并发症。     

Cytokeratins in primary cutaneous amyloidosis

The expression of keratins was investigated immunohistochemically on formalin-fixed and snap-frozen primary cutaneous amyloidosis tissue with a panel of monospecific and polyspecific antikeratin antibodies which recognized keratins K1, K5, K6, K7, K8, K10, K14, K16, K17, K18, and K19. Amyloid deposits in frozen section of seven cases of macular amyloidosis and lichen amyloidosus always reacted with antibodies LP34 (labeling K5, K6 and K18) MNF (labeling K5, K6, K8, K10, K17 and K18) and RCK 102 (labeling K5 and K8); frozen section in one case each of the seven cases also reacted with antibodies LL001 (labeling K14), Lp1K (labeling K7 and K17), and LP2K (labeling K19), LP1K (labelling K7 and K17), and LP2K (labelling K19), In formalin fixed section of 13 cases of macular amyloidosis and lichen amyloidosus amyloid deposits were labeled with LP34 in three section LL020 ()labelling keratins K5 and K6) in one section and LP2K in two section. In nodular primary cutaneous amyloidosis amyloid deposits were not labeled with any antikeratin antibodies. These data confirm that amyloid in macular amyloidosis and lichen amyloidosus contains keratin epitopes, and suggests derivation of the fibrillar component from keratin intermediate filaments Several different keratins appear to undergo conversion to amyloid, LP34, MNF 116 and RCK 102 antibodies, which have in common the labelling of keratin K5, may be useful in the diagnosis of macular and popular amyloidosis with frozen tissue section.