The toe pole test for evaluation of arterial insufficiency in diabetic patients.
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OBJECTIVES: to evaluate if the pole test at the toe level can be used for assessment of arterial insufficiency in diabetic patients. METHODS: twenty-five legs in 23 diabetic patients suffering from leg ischaemia were examined prospectively. A laser Doppler probe was attached to the pulp of the first toe to monitor perfusion continuously before and after occluding the arterial inflow with a cuff and during elevation of the leg until perfusion disappeared (the pole test). At ankle level the examinations were made similarly but with an ankle cuff and a hand-held Doppler. RESULTS: in the 44% (11/25) of the legs where it was possible to compare cuff blood pressure at ankle level with the pole test, the cuff measurements were significantly higher (p <0.01). In 13 of the remaining 14, maximal elevation did not result in disappearance of the Doppler signal. At toe level where 76% (19/25) of the legs could be compared, there was no significant difference between the two methods. CONCLUSION: the pole test can be used at the toe level to evaluate arterial insufficiency in diabetes. When used in the toe, the pole test can assess pressures below 55-70 mmHg, while only pressures below 45 mmHg can be determined at the ankle level. Falsely elevated blood pressure in diabetics is probably of less importance in digital arteries than in ankle arteries, which makes cuff pressure at toe level a more acceptable approximation. (+info)
Thigh isosulfan blue injection in the treatment of postoperative lymphatic complications.
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Postoperative lymphatic complications after infrainguinal revascularization are troublesome and potentially serious complications. Vital dye injection into the web spaces of the foot has been recommended as a simple and reliable method to identify lymphatic channel disruption before groin exploration. Such distal injections, however, are not always successful. We describe a modified technique using a proximal thigh injection with isosulfan blue, which is faster and more useful than the distal web space method. (+info)
Intermediate-term outcome of primary digit amputations in patients with diabetes mellitus who have forefoot sepsis requiring hospitalization and presumed adequate circulatory status.
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PURPOSE: The intermediate success and outcome of primary forefoot amputations in patients with diabetes mellitus who have sepsis limited to the forefoot and presumed adequate forefoot perfusion, as determined by means of noninvasive methods, was studied. METHODS: Cases of a university hospital-based practice from January 1984 to April 1998 were retrospectively reviewed. Patients included had diabetes mellitus with forefoot sepsis requiring immediate hospitalization for digit amputations who had adequate arterial circulation for healing based on noninvasive and clinical assessment: palpable pedal pulses (29%), "compressible" ankle pressure of 70 mm Hg or higher (48%), pulsatile metatarsal waveforms (67%), and/or toe pressure higher than 55 mm Hg (36%). All patients underwent a primary single- or multiple-digit amputation (through the interphalangeal joint, metatarsal head, or metatarsal shaft). Additional forefoot procedures (debridement, digit amputation) were performed during the follow-up period as needed for persistent or recurrent infection. The main outcome variables were recurrent or persistent foot infection (defined as requiring rehospitalization for antibiotics, wound care, and/or reoperation), the number of repeat operations and hospitalizations for salvage of limbs with recurrent or persistent infections, and time to complete forefoot healing or foot amputation. RESULTS: Ninety-two patients who had diabetes mellitus with 97 forefoot infections comprised the study group. Ninety-seven primary digit amputations (34 through interphalangeal joints, 28 through metatarsal heads, 35 through metatarsal shafts) were performed. The median length of hospital stay was 10 days. There were no operative deaths. The mean follow-up period was 21 months (range, 3 days to 105 months). The primary amputation healed (without persistent infection) in only 38 limbs (39%), at a mean time of 13 +/- 10 weeks. Twenty-three limbs (24%) had not healed the primary amputation without evidence of persistent infection at last follow-up (mean, 12 weeks). Infection persisted in 35 limbs (36%), and infection recurred in 15 of 38 (40%) healed limbs. An average of 1.0 reoperations (range, 0 to 3) and 1.6 rehospitalizations (range, 1 to 4) were involved in salvage attempts in these recurrent/persistent infections. Five persistent and five recurrent infections ultimately healed (mean, 53 weeks). Complete healing was achieved in only 33 of 97 limbs (34%). Twenty-two foot amputations (20 transtibial, two Syme's) were performed (mean, 49 +/- 74 weeks; 20 for persistent infection). Eighteen persistent/recurrent infections remained unhealed at the last follow-up examination (mean, 105 weeks). CONCLUSION: Patients with diabetes mellitus who have sepsis limited to the forefoot requiring acute hospitalization and undergoing primary digit amputations have a high incidence of intermediate-term, persistent, and recurrent infection, leading to a modest rate of limb loss, despite having apparently salvageable lesions and noninvasive evidence of presumed adequate forefoot perfusion. (+info)
A blueprint for movement: functional and anatomical representations in the human motor system.
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Despite a clear somatotopic organization of the motor cortex, a movement can be learned with one extremity and performed with another. This suggests that there exists a limb-independent coding for movements. To dissociate brain regions coding for movement parameters from those relevant to the chosen effector, subjects wrote their signature with their dominant index finger and ipsilateral big toe, and we determined those areas activated by both conditions using functional magnetic resonance imaging. The results show that movement parameters for this highly trained movement are stored in secondary sensorimotor cortices of the extremity with which it is usually performed, i.e., the dominant hand, including dorsal and ventral lateral premotor cortices. These areas can be accessed by the foot and are therefore functionally independent from the primary representation of the effector. Thus, somatotopy in secondary structures in the human motor system seems to be defined functionally, and not on the basis of anatomical representations. (+info)
Loss of synaptic depression in mammalian anterior cingulate cortex after amputation.
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Two forms of activity-dependent long-term depression (LTD) in the CNS, as defined by their sensitivity to the blockade of NMDA receptors, are thought to be important in learning, memory, and development. Here, we report that NMDA receptor-independent LTD is the major form of long-term plasticity in the anterior cingulate cortex (ACC). Both L-type voltage-gated calcium channels and metabotropic glutamate receptors are required for inducing LTD. Amputation of a third hindpaw digit in an adult rat induced rapid expression of immediate early genes in the ACC bilaterally and caused a loss of LTD that persisted for at least 2 weeks. Our results suggest that synaptic LTD in the ACC may contribute to enhanced neuronal responses to subsequent somatosensory stimuli after amputation. (+info)
Cholesterol embolism in a patient with inflammatory abdominal aortic aneurysm.
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A 66-year-old man whose renal function had progressively deteriorated had an elevated blood pressure and also was found to have an inflammatory abdominal aortic aneurysm (AAA). Blood examination revealed that he had eosinophilia. Livedo reticularis of the toes developed, and a skin biopsy specimen showed embolization of atheromatous plaques in the arterioles of the subcutaneous tissue. Progressive enlargement of inflammatory AAA may have dislodged the atheromatous plaques, resulting in cholesterol embolism. (+info)
Combinatorial signaling through BMP receptor IB and GDF5: shaping of the distal mouse limb and the genetics of distal limb diversity.
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In this study, we use a mouse insertional mutant to delineate gene activities that shape the distal limb skeleton. A recessive mutation that results in brachydactyly was found in a lineage of transgenic mice. Sequences flanking the transgene insertion site were cloned, mapped to chromosome 3, and used to identify the brachydactyly gene as the type IB bone morphogenetic protein receptor, BmprIB (ALK6). Expression analyses in wild-type mice revealed two major classes of BmprIB transcripts. Rather than representing unique coding RNAs generated by alternative splicing of a single pro-mRNA transcribed from one promoter, the distinct isoforms reflect evolution of two BmprIB promoters: one located distally, driving expression in the developing limb skeleton, and one situated proximally, initiating transcription in neural epithelium. The distal promoter is deleted in the insertional mutant, resulting in a regulatory allele (BmprIB(Tg)) lacking cis-sequences necessary for limb BmprIB expression. Mutants fail to generate digit cartilage, indicating that BMPRIB is the physiologic transducer for the formation of digit cartilage from the skeletal blastema. Expansion of BmprIB expression into the limb through acquisition of these distal cis-regulatory sequences appears, therefore, to be an important genetic component driving morphological diversity in distal extremities. GDF5 is a BMP-related signal, which is also required for proper digit formation. Analyses incorporating both Gdf5 and BmprIB(Tg) alleles revealed that BMPRIB regulates chondrogenesis and segmentation through both GDF5-dependent and -independent processes, and that, reciprocally, GDF5 acts through both IB and other type I receptors. Together, these findings provide in vivo support for the concept of combinatorial BMP signaling, in which distinct outcomes result both from a single receptor being triggered by different ligands and from a single ligand binding to different receptors. (+info)
Bmp-4 requires the presence of the digits to initiate programmed cell death in limb interdigital tissues.
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The effects of Bmp-4 on interdigital cell death were investigated in the mouse. Affi-Gel beads, loaded with recombinant Bmp-4 protein, were transplanted into the interdigital tissues of day 12.5 hindlimb, ex utero. It was established that Bmp-4 could induce precocious interdigital cell death. Using in situ hybridization, the expression patterns of bmp-4 and alk-6 receptor were established. Both genes were found coexpressed in the interdigital region of 12.5- and 13. 5-day hindlimbs. This suggests that Bmp-4 may act in an autocrine fashion. We have also studied the effects of Bmp-4 on 12.5-day interdigital tissue cultures. In all specimens examined, the interdigital tissues produced cartilage instead of participating in cell death. The addition of exogenous Bmp-4 to the interdigital cultures did not induce apoptosis but instead enhanced chondrogenesis. The discrepancy between the effects of Bmp-4 in vitro and ex utero was attributed to the presence of digits. When a flanking digit was left attached to the interdigital tissues, in vitro, Bmp-4 promoted apoptosis instead of chondrogenesis. In sum, the results suggest that Bmp-4 is a multifunctional protein and its effect on the interdigital tissues is dependent on the modulating influence of the digits. (+info)