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

Acute chondral or osteochondral lesions of the ankle joint are typically co entities of ankle sprains and ankle fractures. The exact inicidence is not clear, however clinical and radiological studies suggest that this entity is more common then assumed and probably frequently missed in an acute trauma situation. The initial clinical examination and conventioanl radiographs are often inconclusive. In a severe ankle injury, CT scans and MRI are useful diagnostic tools to assess chondral or osteochondral injury. If diagnosed, surgical treatment consists of either debridment and bone marrow stimulation, or refixation. Return to sports depends on additional injury to the joint as well as patients and sports specific condition.

Acute Ankle Osteochondral and Chondral Lesions

Lateral Ankle Ligament Reconstruction Using Plantaris Autograft

Lateral Calcaneal Lengthening Osteotomy for Supple Adult Flatfoot

Morton’s neuroma is a common cause of metatarsalgia which characterized by enlargement of interdigital nerve possibly due to nerve entrapment. Morton’s neuroma is usually common among middle age population with female gender predominance. Diagnosis of Morton’s neuroma is essentially clinical. Imaging modalities may help to delineate and localize the nerve lesion. Prone position foot MRI is associated with higher visibility of Morton’s neuroma. Identification of Morton’s neuroma, as a cause of metatarsalgia, tends to be missed by clinicians. Hence, high index of suspicion should be invested for this purpose. Proper footwear awareness should be emphasized among athletes. The cross-training shoes are discouraged for long distance running. Local steroid injection may provide temporary relief. Ultrasound-guided injection can improve the localization of injection. Neurectomy of the thickened nerve is considered the standard surgical treatment to date. Majority of surgeons prefer dorsal approach for first-time excision of Morton’s neuroma despite of its limited exposure reserving the plantar approach to the revision cases. Plantar surgical approach provides direct anatomical access and allows wide exploration of the area of neuroma. Recurrent neuroma is a major concern after neurectomy. Deep burial of nerve stump within the intermetatarsal soft tissues might minimize the risk of recurrent neuroma formation.

Victor Valderrabano

Papers

Acute Ankle Osteochondral and Chondral Lesions

Lateral Ankle Ligament Reconstruction Using Plantaris Autograft

Lateral Calcaneal Lengthening Osteotomy for Supple Adult Flatfoot

Morton’s neuroma in sports

Infected unstable Charcot ankle neuroarthropathy, any hope before amputation? A prospective study