The value of toe pulse waves in determination of risks for limb amputation and death in patients with peripheral arterial disease and skin ulcers or gangrene.
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OBJECTIVES: The purpose of this study was to determine whether the presence of low amplitude of pulse waves recorded from the toes is related to the risk of subsequent amputation and death in patients with skin ulcers or gangrene and peripheral arterial disease, and how the risk of low wave amplitude relates to the risk associated with low peripheral pressures. METHODS: A total of 309 patients with 346 limbs with skin lesions and arterial disease referred to the vascular laboratory were followed up for an average of 5 years (range, 1-8 years). Measurements were carried out to obtain ankle and toe pressures, pressure indices, and toe pulse wave amplitude. These variables were related to the risks of major amputation and total and cardiovascular death by means of the Cox proportional hazards model. RESULTS: Low toe pulse wave amplitude (< or = 4 mm) was associated with increased risk of amputation (relative risks 4.20 in all limbs and 2.63 in those with toe pressure < or = 30 mm Hg; P <.01). Wave amplitude remained significantly associated with increased risk of amputation after controlling for each pressure variable (P <.01). Low pulse wave amplitude and toe/brachial index were associated with increased risks of both total and cardiovascular death in all patients (relative risks ranged from 1.43-1.73; P <.05) and in those with toe pressure of 30 mm Hg or less (relative risks 1.56-1.90; P <.05). CONCLUSIONS: Low toe pulse wave amplitude is related significantly to increased risks of amputation and death in patients with skin lesions and arterial disease. The presence of low wave amplitude provides significant information in addition to peripheral pressures with respect to the risk of amputation. (+info)
Lift-based paddling in diving grebe.
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To examine the hydrodynamic propulsion mechanism of a diving great crested grebe (Podiceps cristatus), the three-dimensional kinematics was determined by digital analysis of sequential video images of dorsal and lateral views. During the acceleration phase of this foot-propelled bird, the feet move through an arc in a plane nearly normal to the bird's line of motion through the water, i.e. the toes move dorsally and medially but not caudally relative to the water. The kinematics of the grebe's lobed feet is different from that in anseriforms, whose feet move in a plane mostly parallel to the bird's line of progress through the water. Our results suggest that the foot-propelled locomotor mechanism of grebes is based primarily on a lift-producing leg and foot stroke, in contrast to the drag-based locomotion assumed previously. We suggest that the lift-based paddling of grebes considerably increases both maximum swimming speed and energetic efficiency over drag-based propulsion. Furthermore, the results implicate a new interpretation of the functional morphology of these birds, with the toes serving as a self-stabilizing multi-slotted hydrofoil during the power phase. (+info)
Chick vincula: elastic structures with a check-rein mechanism.
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From their mode of attachment and their elastic composition, it is clear that the vincula of the chick serve other functions besides that of carrying blood vessels to the digital flexor tendons within their synovial sheaths. Evidence is presented in support of the argument that elastic fibres bear the brunt of rapidly applied tensile forces and that the interweaving collagen fibres only become taut when the vincula are stretched to the limit and about to tear. Our hypothesis is that the collagen serves as a check-rein mechanism in an otherwise elastic structure. (+info)
Interobserver and intraobserver reproducibility of peripheral blood and oxygen pressure measurements in the assessment of lower extremity arterial disease.
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INTRODUCTION: Peripheral blood pressure measurements play a prominent role in the diagnosis and follow-up of patients with peripheral vascular diseases. Toe pressure of the hallux (TP1) and second toe (TP2) and transcutaneous oxygen pressure (TCPO2) measurements are becoming more important. The ankle/brachial pressure index (ABPI) is known to be a reliable parameter, but the toe pressure and TCPO2 are evaluated less thoroughly. Therefore, we evaluated the reproducibility of TP1, TP2, TCPO2, ABPI, ankle pressure (AP), and brachial pressure (BP). PATIENTS AND METHODS: In 54 patients with various stages of peripheral vascular disease, the intraobserver and interobserver reproducibility of BP, AP, ABPI, TP1, TP2, and TCPO2 was investigated by calculating the repeatability coefficient (RC) and the intraclass correlation coefficient (ICC) and by using Bland-Altman plots. RESULTS: The intraobserver and interobserver reproducibility at 1 day and after 1 week of BP, AP, ABPI, and TP1 was substantial and comparable (ICC range, 0.80-0.99), except for the BP after 1 week. The TP2 and TCPO2 were less reproducible (ICC range, 0.62-0.98). The interobserver RC of BP was 31 mm Hg; of AP, 44 mm Hg; of ABPI, 27%; of TP1, 41 mm Hg; of TP2, 67 mm Hg; and of TCPO2; 30 mm Hg. The difference plot showed that the observer variability was equally distributed across the range of pressure in all measurements. CONCLUSION: The BP, AP, ABPI, and TP1 have a substantial intraobserver and interobserver reproducibility, whereas TP2 and TCPO2 show worse reproducibility. Especially when low values (or values around a cutoff value) are measured, the RC should be taken into account, and repetition of the measurement is advocated. (+info)
Selective lengthening of the proximal flexor tendon in the management of acquired claw toes.
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We report the management of the acquired claw-toe deformity in ten adults. Each patient developed a varying number of claw toes at a mean interval of six months after the time of injury. There was clinical evidence of an acute compartment syndrome in one case. The clawing occurred at the start of heel-rise in the stance phase of gait. At this stage the patients complained of increasing pain and pressure on the tips of the toes. The deformities were corrected by lengthening flexor hallucis longus and flexor digitorum longus alone or in combination. The presence of variable intertendinous digitations between the tendons of flexor hallucis longus and flexor digitorum longus means that in some cases release of flexor hallucis longus alone may correct clawing of lesser toes. (+info)
Functions of the growth arrest specific 1 gene in the development of the mouse embryo.
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The growth arrest specific 1 (gas1) gene is highly expressed in quiescent mammalian cells (Schneider et al., 1988, Cell 54, 787-793). Overexpression of gas1 in normal and some cancer cell lines could inhibit G(0)/G(1) transition. Presently, we have examined the functions of this gene in the developing mouse embryo. The spatial-temporal expression patterns for gas1 were established in 8.5- to 14.5-day-old embryos by immunohistochemical staining and in situ hybridization. Gas1 was found heterogeneously expressed in most organ systems including the brain, heart, kidney, limb, lung, and gonad. The antiproliferative effects of gas1 on 10.5 and 12.5 day limb cells were investigated by flow cytometry. In 10.5 day limbs cells, gas1 overexpression could not prevent G(0)/G(1) progression. It was determined that gas1 could only induce growth arrest if p53 was also coexpressed. In contrast, gas1 overexpression alone was able to induce growth arrest in 12.5 day limb cells. We also examined the cell cycle profile of gas1-expressing and nonexpressing cells by immunochemistry and flow cytometry. For 10.5 day Gas1-expressing heart and limb cells, we did not find these cells preferentially distributed at G0/G1, as compared with Gas1-negative cells. However, in the 12.5 day heart and limb, we did find significantly more Gas1-expressing cells distributed at G0/G1 phase than Gas1-negative cells. These results implied that Gas1 alone, during the early stages of development, could not inhibit cell growth. This inhibition was only established when the embryo grew older. We have overexpressed gas1 in subconfluent embryonic limb cells to determine the ability of gas1 to cross-talk with various response elements of important transduction pathways. Specifically, we have examined the interaction of gas1 with Ap-1, NFkappaB, and c-myc responsive elements tagged with a SEAP reporter. In 10.5 day limb cells, gas1 overexpression had little effect on Ap-1, NFkappaB, and c-myc activities. In contrast, gas1 overexpression in 12.5 day limb cells enhanced AP-1 response while it inhibited NFkappaB and c-myc activities. These responses were directly associated with the ability of gas1 to induce growth arrest in embryonic limb cells. In the 12.5 day hindlimb, gas1 was found strongly expressed in the interdigital tissues. We overexpressed gas1 in these tissues and discovered that it promoted interdigital cell death. Our in situ hybridization studies of limb sections and micromass cultures revealed that, during the early stages of chondrogenesis, only cells surrounding the chondrogenic condensations expressed gas1. The gene was only expressed by chondrocytes after the cartilage started to differentiate. To understand the function of gas1 in chondrogenesis, we overexpressed the gene in limb micromass cultures. It was found that cells overexpressing gas1/GFP could not participate in cartilage formation, unlike cells that just express the GFP reporter. We speculated that the reason gas1 was expressed outside the chondrogenic nodules was to restrict cells from being recruited into the nodules and thereby defining the boundary between chondrogenic and nonchondrogenic forming regions. (+info)
Expression pattern of Irx1 and Irx2 during mouse digit development.
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Irx1 and Irx2 are members of the murine Iroquois homeobox (Irx) gene family. In this study, we describe the dynamic expression pattern of these genes during limb development with a focus on digit formation. We further present a comparative expression analysis with Gli genes (Gli1, Gli2, Gli3). Gli1, Gli2, and Gli3 were suggested for candidate regulators of the Irx genes. The expression was studied between E11.5 and E14.5 when the digits are being formed. Irx1 and Irx2 reproduce the developmental program of the digits in time and space and the Irx1 provides an early and excellent marker for this process. Our analysis also indicates that the expression of Irx1, Gli1 and Irx2, Gli2 are relative to each other. In contrast, Gli3 exhibits a different expression pattern. (+info)
Toe-to-finger transfer for post-traumatic reconstruction of the fingerless hand.
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OBJECTIVE: To assess the utility of toe-to-finger transfers (TFTs) for post-traumatic reconstruction of the fingerless hand. DESIGN: A case series. SETTING: A regional trauma centre. PATIENTS: Eight men, mean age was 36 years (range from 25-59 yr), who had lost all the fingers from a hand due to a crush-degloving injury (6 patients), frostbite (1 patient) or a burn injury (1 patient). INTERVENTION: TFT. Twelve TFTs were cone and the mean time from injury to reconstruction was 17.2 months. MAIN OUTCOME MEASURES: Objective (range of motion, moving 2-point discrimination, grip strength, key pinch, Jebsen-Taylor hand assessment, return to work) and subjective (activities of daily living and a questionnaire) measures. RESULTS: Eleven of the 12 transfers survived. Six of the 7 in whom the transfer was successful were available for follow-up (mean 45 mo). Range of motion was 10 degrees at the distal interphalangeal joint, 18 degrees at the proximal interphalangeal joint and 59 degrees at the metacarpophalangeal joint. Sensation was protective in all. Grip strength and key pinch were 26.1% and 70.2% of the contralateral hand respectively. Jebsen-Taylor assessment indicated that basic activities were possible but slowed. All 6 patients returned to work and could perform 92.6% of the activities of daily living unassisted. Hand and foot symptoms were mild. Two-thirds were appearance conscious, 5 of the 6 went on to altered vocations and all reported overall satisfaction as high. CONCLUSION: This study supports TFT for reconstruction of the fingerless hand in that, although transferred toe function may be poorer than a normal finger, the hand is restored to a useful, sensate and versatile functional unit, such that global hand and patient function, as well as patient satisfaction, are very good. (+info)