Probability Distributions.- Linear Models for Regression.- Linear Models for Classification.- Neural Networks.- Kernel Methods.- Sparse Kernel Machines.- Graphical Models.- Mixture Models and EM.- Approximate Inference.- Sampling Methods.- Continuous Latent Variables.- Sequential Data.- Combining Models.

Pattern Recognition and Machine Learning

结节病易误诊,据王洪武等~([1])收集国内18篇关于此病误诊的文献,误诊率高达63.2%,当然有误诊就会有误治,如孙永昌等~([2])报道26例结节病在影像学检查诊断的第一印象中拟诊结核5例,其中就有2例完成规范的抗结核治疗,为此应引起临床对本病诊治的重视。

Sarcoidosis

Articular cartilage was predicted to be one of the first tissues to successfully be regenerated, but this proved incorrect In contrast, bone (but also vasculature and cardiac tissues) has seen numerous successful reparative approaches, despite consisting of multiple cell and tissue types and, thus, possessing more complex design requirements Here, we use bone-regeneration successes to highlight cartilage-regeneration challenges: such as selecting appropriate cell sources and scaffolds, creating biomechanically suitable tissues, and integrating to native tissue We also discuss technologies that can address the hurdles of engineering a tissue possessing mechanical properties that are unmatched in human-made materials and functioning in environments unfavorable to neotissue growth

/pdf/unlike-bone-cartilage-regeneration-remains-elusive-1v15bd07dw.pdf

Unlike Bone, Cartilage Regeneration Remains Elusive

This review analyzes the literature of bone grafts and introduces tissue engineering as a strategy in this field of orthopedic surgery. We evaluated articles concerning bone grafts; analyzed characteristics, advantages, and limitations of the grafts; and provided explanations about bone-tissue engineering technologies. Many bone grafting materials are available to enhance bone healing and regeneration, from bone autografts to graft substitutes; they can be used alone or in combination. Autografts are the gold standard for this purpose, since they provide osteogenic cells, osteoinductive growth factors, and an osteoconductive scaffold, all essential for new bone growth. Autografts carry the limitations of morbidity at the harvesting site and limited availability. Allografts and xenografts carry the risk of disease transmission and rejection. Tissue engineering is a new and developing option that had been introduced to reduce limitations of bone grafts and improve the healing processes of the bone fractures and defects. The combined use of scaffolds, healing promoting factors, together with gene therapy, and, more recently, three-dimensional printing of tissue-engineered constructs may open new insights in the near future.

/pdf/bone-regenerative-medicine-classic-options-novel-strategies-3fz7aanv1p.pdf

Bone regenerative medicine: classic options, novel strategies, and future directions

Ca(2+) is an essential ion in all organisms, where it plays a crucial role in processes ranging from the formation and maintenance of the skeleton to the temporal and spatial regulation of neuronal function. The Ca(2+) balance is maintained by the concerted action of three organ systems, including the gastrointestinal tract, bone, and kidney. An adult ingests on average 1 g Ca(2+) daily from which 0.35 g is absorbed in the small intestine by a mechanism that is controlled primarily by the calciotropic hormones. To maintain the Ca(2+) balance, the kidney must excrete the same amount of Ca(2+) that the small intestine absorbs. This is accomplished by a combination of filtration of Ca(2+) across the glomeruli and subsequent reabsorption of the filtered Ca(2+) along the renal tubules. Bone turnover is a continuous process involving both resorption of existing bone and deposition of new bone. The above-mentioned Ca(2+) fluxes are stimulated by the synergistic actions of active vitamin D (1,25-dihydroxyvitamin D(3)) and parathyroid hormone. Until recently, the mechanism by which Ca(2+) enter the absorptive epithelia was unknown. A major breakthrough in completing the molecular details of these pathways was the identification of the epithelial Ca(2+) channel family consisting of two members: TRPV5 and TRPV6. Functional analysis indicated that these Ca(2+) channels constitute the rate-limiting step in Ca(2+)-transporting epithelia. They form the prime target for hormonal control of the active Ca(2+) flux from the intestinal lumen or urine space to the blood compartment. This review describes the characteristics of epithelial Ca(2+) transport in general and highlights in particular the distinctive features and the physiological relevance of the new epithelial Ca(2+) channels accumulating in a comprehensive model for epithelial Ca(2+) absorption.

https://www.physiology.org/doi/pdf/10.1152/physrev.00003.2004

Calcium Absorption Across Epithelia

Die Fraktur des Processus lateralis tali (Snowboarder’s Foot)

Calcaneal fractures are the most common tarsal fractures and their treatment is still debated today. We intend in this update to highlight the points of controversy and clarify the consensus, especially in the treatment of intra-articular fractures, as well as to describe the management of major complications.

[Calcaneal fractures: controversies and consensus].

Severe haemophilia with recurrent joint bleeding maycause secondary ankle osteoarthritis [1]. Commonradiographic ﬁndings of haemophilic arthropathyinclude subchondral cysts, osteoporosis, enlargedepiphyses, irregular subchondral surface, narrowing ofthe joint space and gross joint deformities [2]. Haemo-philic pseudotumour occurs in approximately 2% ofpatients with severe haemophilia [3].In the current literature, numerous treatmentoptions have been described for various stages ofhaemophilic ankle arthropathy [4,5]. Ankle arthrode-sis has been considered the standard treatment optionin patients with haemophilic end-stage ankle arthropa-thy [6]. In the last two decades, total ankle replace-ment has become a feasible treatment option [7].However, in patients with asymmetric ankle osteoar-thritis and a concomitant deformity, where a substan-tial part of the tibiotalar joint remains preserved,procedures that sacriﬁce the native joint may not bean ideal treatment option. In patients with posttrau-matic ankle osteoarthritis, promising short- and mid-term results have been reported in those whounderwent supramalleolar realignment surgery [8].However, there is a paucity of literature to addressthe use of supramalleolar realignment surgery inpatients with bleeding disorders. Herein, we describethe successful orthopaedic management of a patientwith severe haemophilia A and Noonan syndrometreated by debridement of cysts, ﬁlling with allograftand allomatrix, and bilateral hindfoot osteotomies. Inaddition to describing our experience, we also providea review of the current literature on realignment sur-gery for ankle haemophilic arthropathy.A 29-year-old man with severe haemophilia A(FVIII:C < 1.0) and Noonan syndrome presented toour clinic. His Noonan syndrome [9] was noted to beof autosomal dominant genetic origin, also occurringin three out of six of his siblings. The patient showedcharacteristic signs of Noonan syndrome, includingshort body height (158 cm) with associated dispropor-tionality, a ventricular septum defect with stenosis ofthe pulmonal valve, and unilateral cryptorchism.Details regarding association between Noonan syn-drome and bleeding disorders are described in the cur-rent literature [10].The patient’s haemophilia A was diagnosed whenhe was 2 months old, receiving factor substitutionsince then. He had a history of recurrent intraarticularbleeding in both ankles (in the last 12 months fourand three episodes in the right and left ankle respec-tively). The patient presented in our orthopaedic out-patient clinic with bilateral ankle and hindfoot painwith the right side being more symptomatic. Clinicallyhe had peritalar instability with supramalleolar varusmalalignment of the ankle in combination with infra-malleolar valgus malalignment of the heel (Figs 1aand 2a). His ability to walk was severely limited bypain and malalignment to less than 100 m. Hereported pain as 10/10 on the visual analogue scale.The total range of motion of the right and left anklejoints was 20° and 15° respectively. The AmericanOrthopaedic Foot & Ankle Society (AOFAS) hindfootscore was 65 out of a maximum of 100 points. Radio-graphs demonstrated gross bilateral cysts of the distaltibia with the medial distal tibial angle on the rightand left side being 65.5° and 77.0° respectively. Com-puted tomography revealed extensive cystic lesions,especially on the right side (Figs 1b and 2b). On theright side, a large cyst left a cortical defect of approxi-mately 3 9 4 cm on the medial aspect of the distaltibia, including the whole medial malleolus; only theperiosteum covered this cyst. A thin rim ofsubchondral bone persisted on the medial malleolusand the tibial plafond. Scintigraphy showed metabolic

Ankle joint‐preserving surgery in a patient with severe haemophilia and Noonan syndrome: case report and literature review

Unterschenkel-Muskelatrophie bei Arthrose des oberen Sprunggelenks und deren Rehabilitation nach Implantation einer Sprunggelenksprothese

Center for Advanced Orthopaedic Studies,Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, RN 115,Boston, MA 02215, USA* Corresponding authors. Orthopaedic Department, Osteoarthritis Research Center Basel,University Hospital of Basel, University of Basel, Spitalstrasse 21, Basel CH-4031, Switzerland.E-mail addresses: victor.valderrabano@usb.ch; alexej.barg@usb.ch

Victor Valderrabano

Papers

Die Fraktur des Processus lateralis tali (Snowboarder’s Foot)

[Calcaneal fractures: controversies and consensus].

Ankle joint‐preserving surgery in a patient with severe haemophilia and Noonan syndrome: case report and literature review

Unterschenkel-Muskelatrophie bei Arthrose des oberen Sprunggelenks und deren Rehabilitation nach Implantation einer Sprunggelenksprothese

Etiology, Diagnostics, and Classification