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Haematopoiesis is one of the most well understood stem-cell associated processes. It is a process in which pluripotent hematopoietic stem cells (HSCs) self-proliferate and differentiate into all types of blood cells. The process takes place in marrow of the flat bones in adults, however its location changes several times through embryonic and foetal development. Given the broad range of blood cells and the major differences in their build and function, together with the fact that their numbers need to be maintained within relatively narrow margins in order to maintain homeostasis despite changing environmental conditions, makes the whole process of haematopoiesis highly regulated and depending on a variety of growth factors. When influenced by those, HSCs undergo several irreversible steps, with every next one committing them to an even more specialised fate, ending with all the specific types of mostly short-lived blood cells, that are unable to proliferate on their own and need constant replenishment from the HSC pool. Because the process of haematopoiesis is the only source of all the members of the group of cells performing a range of highly important roles in functioning of the organism, significant damage to the underlying stem cells can cause a range of severe diseases. Many treatments are suggested for managing their symptoms or slowing progress, with bone marrow transplant being one of the only ones that offer possible permanent solution and, despite being a relatively risky procedure, is being widely performed, with the methods constantly improving in order to achieve progressively better results in both treatability and survivability of the patients.

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Contrasting with the situation found in birds and mammals, sex chromosomes are generally homomorphic in poikilothermic vertebrates. This homomorphy was recently shown to result from occasional X-Y recombinations (not from turnovers) in several European species of tree frogs (Hyla arborea, H. intermedia and H. molleri). Because of recombination, however, alleles at sex-linked loci were rarely diagnostic at the population level; support for sex linkage had to rely on multilocus associations, combined with occasional sex differences in allelic frequencies. Here, we use direct evidence, obtained from anatomical and histological analyses of offspring with known pedigrees, to show that the Eastern tree frog (H. orientalis) shares the same pair of sex chromosomes, with identical patterns of male heterogamety and complete absence of X-Y recombination in males. Conservation of an ancestral pair of sex chromosomes, regularly rejuvenated via occasional X-Y recombination, seems thus a widespread pattern among Hyla species. Sibship analyses also identified discrepancies between genotypic and phenotypic sex among offspring, associated with abnormal gonadal development, suggesting a role for sexually antagonistic genes on the sex chromosomes.

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The authors present a case of bilateral Hawkins type II talar neck fractures sustained during a motocross race in a 23 year old man. Due to the complexity of the injuries, open reduction with internal fixation and primary subtalar joint arthrodesis was performed bilaterally. This is one of the few cases of bilateral talar neck fractures reported in the literature in the past 15 years and one of the first utilizing open reduction and internal fixation with concomitant subtalar joint arthrodesis as a primary treatment.

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The diagnosis of pedal osteomyelitis is often complicated by the presence of pre-existing bony abnormalities. In this study, the utility of radiolabeled white blood cell imaging for the detection of complicated pedal osteomyelitis was evaluated. Twenty-seven men and women were prospectively enrolled and underwent plain film radiography, three-phase bone scan, and Tc-99m hexamethylpropylamine oxine white blood cell scintigraphy of their feet. The presence or absence of osteomyelitis was confirmed in all subjects by microbiologic and histopatholigic analysis of resected bone tissue. The results indicated that white blood cell imaging was more sensitive (90%) and specific (86%) for infection than either bone scan (75% sensitive, 29% specific) or plain film radiography (55% sensitive, 57% specific). This preliminary study suggests that Tc-99m hexamethylpropylamine oxine-labeled white blood cell scintigraphy is a simple, accurate test for the detection of pedal osteomyelitis.

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Fibrosarcomas make up a small percentage of soft somatic tissue malignancies. Fibrosarcomas of the foot and ankle constitute an even smaller percentage of all reported cases with respect to anatomic locations. The postoperative local recurrence is great, and the diagnosis is often difficult to make because of the similar microscopic presentation of plantar fibromatosis and fibrosarcoma. A case presentation of a plantar fibrosarcoma, after two failed attempts at excision, with a review of the literature, is discussed.

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The health care academic delivery system is dramatically changing in today's economy. In order to survive, the delivery system must decrease its costs and increase productivity. Integration of academic affiliates and community health care facilities has produced a more efficient health care system and improved medical education. The formation and methodology of the mutual benefits and responsibilities between a health care system and a college of podiatric medicine are examined in detail. Developing unique sharing partnerships can mutually improve medical student experiences, reduce financial burdens, combine joint research projects, and ultimately improve patient care.

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The authors present a case of congenital, bilateral, symmetrical, and purely transverse plane, abductus deformity of the second digit. The deformity appears to be familial in nature, although other possible etiologies remain including premature closure of the distal-lateral epiphysis of the middle phalanx, or a C-shaped epiphysis of the middle phalanx. The authors review a similar deformity described in orthopedic literature known as a delta phalanx.

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The podiatrist's role in occupational health is variable and depends on the type of programs offered to workers, methods of financing and delivering services, and contractual arrangements with management or labor. A positive and necessary impact on occupation-related disorders of the foot may be provided by the podiatrist at three levels of care: primary, secondary, and tertiary prevention or care.

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Flexion contractures in the foot as a sequela of frostbite have received little attention in the medical literature. The authors provide a brief overview of frostbite and present a surgical approach to a case of frostbite arthritis associated with disabling joint deformities.

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