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Mobile mammography: results of a national survey.

PURPOSE: to learn about mobile mammography in the United States. MATERIALS AND METHODS: A survey of 82 questions was designed, pilot tested, and sent to mobile mammography facilities. The questions addressed many aspects of mobile programs, including administrative, financial, equipment, personnel, film processing, quality assurance, and communication of results. RESULTS: Of the 367 facilities that were mailed surveys, 159 facilities completed the survey, and 30 (19%) of those had discontinued their mobile programs. Seventy-six of 158 (48%) mobile facilities had performed mobile mammography for 1-5 years, and 69 of 158 (44%) had performed mobile mammography for more than 5 years. Seventy-two of 156 (46%) facilities were hospital-owned, and 25 of 156 (16%) were radiologist-owned. One hundred seven of 159 (67%) mobile facilities performed screening only. One hundred fourteen of 152 (75%) facilities charged +80.00 or less for screening. Mobile facilities averaged 20 examinations per day and served diverse populations. Sixty-seven of 159 (42%) facilities accepted self-referred women. Thirty-one percent of the facilities performed on-board processing. Only 71 of 149 (47%) facilities were financially profitable or breaking even, but 112 of 154 (73%) facilities would undertake a mobile project again. CONCLUSION: Mobile programs provide an opportunity to increase access to screening mammography, but they face many obstacles.

Data Collection↗

Mobilization and homing of peripheral blood progenitors is related to reversible downregulation of alpha4 beta1 integrin expression and function.

Despite the wide use of mobilized peripheral blood (PB) progenitor cells (PBPC) for clinical transplantation the mechanism(s) underlying their mobilization and subsequent engraftment are still unknown. We compared the adhesive phenotype of CD34(+) colony-forming cells (CFC) in bone marrow (BM) and PB of normal donors before and after administration of granulocyte colony-stimulating factor (G-CSF) for 5 d. G-CSF-mobilized PB CFC cells adhered significantly less to BM stroma, fibronectin, and to the alpha4 beta1 binding fibronectin peptide, CS1, because of decreased expression of the alpha4 integrin. Since incubation of BM CD34(+) cells for 4 d with G-CSF at concentrations found in serum of G-CSF- treated individuals did not affect alpha4-dependent adhesion, G-CSF may not be directly responsible for the decreased alpha4-mediated adhesion of PB CFC. Culture of G-CSF-mobilized PB CD34(+) cells with cytokines at concentrations found in BM stromal cultures upregulated alpha4 expression and restored adhesion of mobilized PB CFC to stroma, fibronectin, and CS1. Adhesion of cultured, mobilized PB CFC to stroma and CS1 could not be further upregulated by the beta1 activating antibody, 8A2. This indicates acquisition of a maximally activated alpha4 beta1 integrin once PB CFC have been removed from the in vivo mobilizing milieu. Thus, decreased alpha4 expression on CD34(+) CFC in PB may be responsible for the aberrant circulation of mobilized PB CD34(+) cells. Reexpression of a maximally activated alpha4 beta1 integrin on mobilized PB CFC removed from the mobilizing in vivo milieu may contribute to the early engraftment of mobilized PBPC.

Antigens, CD34↗

The electric field dependence of DNA mobilities in agarose gels: a reinvestigation.

The electric field dependence of the electrophoretic mobility of linear DNA fragments in agarose gels was reinvestigated in order to correct the observed mobilities for the different temperatures actually present in the gel during electrophoresis in different electric field gradients. When corrected to a common temperature, the electrophoretic mobilities of DNA fragments less than or equal to 1 kilobase pairs (kbp) in size were independent of electric field strength at all field strengths from 0.6 to 4.6 V/cm if the gels contained less than or equal to 1.4% agarose. The mobilities of larger DNA fragments increased approximately linearly with electric field strength. If the agarose concentration was higher than 2%, the mobilities of all DNA fragments increased with increasing electric field strength. The electric field dependence of the mobility was larger in gels cast and run in Tris-borate buffer (TBE) than in gels cast and run in Tris-acetate buffer (TAE), and was more pronounced in gels without ethidium bromide incorporated in the matrix. Ferguson plots were constructed for the various DNA fragments, both with and without extrapolating the temperature-corrected mobilities to zero electric field strength. Linear Ferguson plots were obtained for all fragments less than or equal to 12 kbp in size in agarose gels less than or equal to 1.4% in concentration if the mobilities were first extrapolated to zero electric field strength. Concave upward curvature of the Ferguson plots was observed for DNA fragments greater than or equal to 2 kbp in size at finite electric field strengths. Convex downward curvature of the Ferguson plots was observed for DNA fragments greater than or equal to 1 kbp in size in agarose gels greater than or equal to 2% in concentration. The mobilities of the various DNA fragments, extrapolated to zero agarose concentration and zero electric field strength, decreased with increasing DNA molecular weight; extrapolating to zero molecular weight gave an "intrinsic" DNA mobility of 2.7 x 10(-4) cm2/Vs at 20 degrees C. The pore sizes of LE agarose gels cast and run in TAE and TBE buffers were estimated from the mobility of the DNA fragments.(ABSTRACT TRUNCATED AT 400 WORDS)

Boric Acids↗

Effect of long-term removal of iron from asbestos by desferrioxamine B on subsequent mobilization by other chelators and induction of DNA single-strand breaks.

The long-term removal of iron from crocidolite or amosite by desferrioxamine B (DF) at pH 7.5 or 5.0 was studied. Crocidolite or amosite (1 mg/ml) was suspended in 50 mM NaCl at pH 7.5 or 5.0 with the addition of 1 mM DF for up to 90 days. Although the rate of iron mobilization decreased with time, iron was continuously mobilized from both forms of asbestos at pH 5.0 or 7.5. The amount of iron mobilized from crocidolite was at least twice that mobilized from amosite at either pH. Iron was mobilized more rapidly from crocidolite at pH 5.0 than at 7.5 for the first 15 days, but at later times the amount being mobilized at pH 7.5 became equal to or slightly greater than that at 5.0. For amosite, the mobilization at pH 5.0 was always greater than that at pH 7.5. Next, the effect of iron removal from asbestos by DF on subsequent iron mobilization by a second chelator (EDTA or citrate) and on induction of DNA single-strand breaks (SSBs) was studied. Asbestos, treated for up to 15 days with DF at pH 7.5, was washed to remove ferrioxamine and excess DF, then incubated with EDTA or citrate (1 mM). The rates of iron mobilization from both forms of asbestos by a second chelator decreased as more and more iron was removed by DF. Induction of DNA SSBs also decreased, reflecting the unavailability of iron to catalyze the damage. The results suggest three things. First, if long-term mobilization of iron from asbestos occurs in vivo as has been observed in vitro, it may play a role in the long-term biological effects of asbestos. Second, more rapid mobilization of iron from asbestos fibers may occur when the fibers are phagocytized by cells and maintained in phagosomes where the pH is 4.0-5.0. Third, treatment of asbestos by iron chelators, such as DF, prior to exposure to cultured cells or whole animals, may reduce the biological effects of asbestos resulting from iron, but may not completely eliminate them.

Asbestos, Amosite↗

Dynamic Electrophoretic Mobility of Spherical Colloidal Particles in Concentrated Suspensions

A theory for the dynamic electrophoretic mobility &mgr; of spherical colloidal particles in concentrated suspensions in an oscillating electric field is proposed on the basis of Kuwabara's cell model. The dynamic mobility depends on the frequency omega of the applied electric field and the particle volume fraction phi as well as on the reduced particle radius kappaa (where kappa is the Debye-Hückel parameter and a is the particle radius) and the zeta potential zeta. A mobility formula which involves numerical integration is obtained for particles with zero permittivity and low zeta. It is found that the mobility magnitude decreases with decreasing kappaa as in the static case (omega = 0) and as in the single particle case (phi --> 0) and that it decreases with increasing omega as in the single particle case. However, the phi dependence of the mobility magnitude is much more complicated. Namely, for small kappaa the mobility magnitude decreases with increasing phi as in the static case. For large kappaa it increases with increasing phi. For moderate kappaa and not very low omega the mobility magnitude may exhibit a maximum. In all cases the omega dependence of the mobility magnitude becomes less as phi increases, that is, the dynamic mobility at any omega approaches the static mobility as phi increases. An accurate mobility formula without involving numerical integration applicable for all kappaa at zero particle permittivity and low zeta is also derived. This formula is applicable even for high zeta at kappaa --> infinity unless the dynamic relaxation effect becomes appreciable. Copyright 1997 Academic Press. Copyright 1997Academic Press

Journal Article↗

Reduced mobility and physical activity as predictors of depressive symptoms among community-dwelling older adults: an eight-year follow-up study.

BACKGROUND AND AIMS: Epidemiological research suggests that reduced physical activity and mobility may be associated with depressive symptoms. The present study examines the relative roles of mobility status and physical activity as predictors of depressive symptoms among community-dwelling older adults. METHODS: The subjects comprised randomly selected, non-institutionalized residents of the city of Jyväskylä, central Finland, born in 1904-1923. At baseline, 80% (N = 1224) and after the 8-year follow-up period (1996) 88% (N = 663) of eligible persons were interviewed. All non-institutionalized men and women (N = 384) who participated in both baseline and follow-up interviews, who supplied data on the main questions of interest and who had no depressive symptoms at baseline, were selected for analysis. Depressive symptoms were assessed using the Finnish modified version of Beck's 13-item depression scale (RBDI). Physical activity was assessed on a seven-point scale. Mobility status was defined as the ability to walk two kilometers and climb one flight of stairs. RESULTS: Subjects who were mobility-disabled and had a sedentary life-style had a higher risk (OR = 2.44) for depressive symptoms at follow-up than those who had good mobility and were physically active. The risk was also higher (OR = 1.99) in those who were mobility-disabled and had a physically active life-style, compared with physically active individuals with intact mobility. Those with good mobility had fewer depressive symptoms than those who had mobility problems, irrespective of the level of physical activity. No significant interaction was observed between physical activity and mobility in predicting the development of depressive symptoms. Older age significantly increased, and the number of chronic illnesses tended to increase the risk of developing depressive symptoms during the follow-up period. Gender and length of education were not significant predictors of depressive symptoms. CONCLUSIONS: Mobility problems and older age seem to increase the risk for developing depressive symptoms in elderly people. The risk is not associated with the level of physical activity.

Aged↗

The effect of various chelating agents on the mobilization of iron from reticulocytes in the presence and absence of pyridoxal isonicotinoyl hydrazone.

The chelating agent pyridoxal isonicotinoyl hydrazone (PIH) has recently been shown to mobilize 59Fe from reticulocytes loaded with non-heme 59Fe. In this study, various chelating agents were tested for their ability to effect the mobilization of iron from reticulocytes by PIH. They fall into several groups. The largest group includes chelators such as citrate, ethylenediaminetetracetic acid and desferrioxamine, which fail to affect PIH-induced iron mobilization and do not mobilize iron per se. Either these chelators do not enter reticulocytes or they do not take up iron from PIH-Fe complexes. The second group includes chelators such as 2,2'-bipyridine, 1,10-phenanthroline, bathophenanthroline sulfonate and N,N'-ethylenebis(o-hydroxyphenylglycine) which inhibit PIH-induced iron mobilization from reticulocytes and, when added together with PIH, induce radioiron accumulation in an alcohol-soluble fraction of reticulocytes. It appears that these chelators enter the cell and compete with PIH for 59Fe(II), but having bound iron are unable to cross the cell membrane. Spectral analysis suggests that Fe(II) chelators such as 2,2'-bipyridine and 1,10-phenanthroline remove iron from Fe(II)PIH but are not able to do so from Fe(III)PIH. Then there are compounds such as 2,3-dihydroxybenzoic acid and catechol which potentiate PIH-induced iron mobilization although they are unable to mobilize iron from reticulocytes by themselves. Lastly, there is a group of miscellaneous compounds which include chelators that either potentiate the iron-mobilizing effect of PIH as well as mobilizing iron from reticulocytes by themselves (tropolone), or that reduce PIH-induced iron mobilization while themselves having an iron-mobilizing effect (N,N'-bis(2,3-dihydroxybenzoyl)-1,6-diaminohexane). In further experiments, heme was found to stimulate globin synthesis in reticulocytes, the heme synthesis of which was inhibited by PIH, suggesting that PIH is probably not toxic to the cells.

2,2'-Dipyridyl↗

Tandem mobility mass spectrometry study of electrosprayed tetraheptyl ammonium bromide clusters.

Multiply charged electrospray ions from concentrated solutions of Heptyl4N+Br- (designated A+B- hereafter) in formamide are analyzed mass spectrometrically (MS) following mobility selection in ambient air in a differential mobility analyzer (DMA). Most of the sharp mobility peaks seen are identified as (AB)(n)A+ clusters, with 0 < or = n < ot = 5. One anomalously abundant and mobile ion is identified as NH4+(AB)4. Six ions in the (AB)n(A+)2 series are also identified, completing and correcting earlier mobility data for singly and doubly charged ions up to masses of almost 9000 Da. The more mobile of two broad humps seen in the mobility spectrum includes m/z values approximately from 2500 up to 12,000 Da. It is formed primarily by multiply charged (AB)n(A+)z clusters with multiple ammonium bromide adducts. Because of overlapping of many peaks of different m/z and charge state z, only a few individual species can be identified by MS alone in this highly congested region. However, the spectral simplification brought about by mobility selection upstream of the MS reveals a series of broad modulations in m/z space, with all ions resolved in the second, third, ...sixth modulation being in charge states z = 2, 3, ...6, respectively. Extrapolation of this trend beyond the sixth wave fixes the ion charge state (in some cases up to z = 15) and mass (beyond m = 175,000 u). This wavy structure had been previously observed and explained in terms of ion evaporation kinetics from volatile drops, though without mass identification. All observations indicate that the clusters are formed as charged residues, but their charge state is fixed by the Iribarne-Thomson ion evaporation mechanism. Consequently, the measured curve of cluster diameter versus z yields the two parameters governing ion evaporation kinetics. Clusters with z > 1 and electrical mobility Z > 0.495 cm2/V/s are metastable and evaporate a singly charged cluster, probably (AB)2A+, between the DMA and the MS. Plotting the electrical mobilities Z of the clusters in the form (z/Z)1/2 versus m(1/3) (both proportional to cluster diameter) collapse the data for all cluster sizes and charge states into one single straight line for Z below 0.495 cm2/V/s. This linear relation reveals a uniform apparent cluster density of 0.935 g/cm3 and an effective hard-sphere diameter of the air molecules of 0.44 nm. An anomalous mobility increase is observed at diameters below 3 nm.

Bromides↗

Prehospital ECG transmission: comparison of advanced mobile phone and facsimile devices in an urban Emergency Medical Service System.

OBJECTIVE: To compare the speed and reliability of electrocardiogram (ECG) transmissions from the prehospital setting to a conventional table facsimile device and to an advanced mobile phone in a Helicopter Emergency Medical Service System (HEMS). METHODS: Eighteen authentic ECGs stored in the memory module of a monitor defibrillator were used. The ECGs were (1) sent directly from the monitor defibrillator to a table fax and an advanced mobile phone at the HEMS base; (2) printed out and sent from a mobile fax connected to an ordinary mobile phone to the table fax and the advanced mobile phone at the HEMS base; (3) printed out and sent from an ordinary table fax as well as from a table fax connected to a satellite phone system to the receiving devices at the HEMS base. RESULTS: When the ECGs were sent from the table fax via satellite, the transmission times were longer to the advanced mobile phone than to the table fax at the HEMS base (1 min 54 s+/-0 min 21 s vs. 1 min 37 s+/-0 min 20 s, (mean+/-SD), (P<0.01). Regarding transmission from the other fax devices, there were no differences in transmission times between the two receiving devices. The fastest way to transmit ECGs to the advanced mobile phone was to send it from conventional table fax (1 min 22 s+/-0 min 18 s) and the longest transmission times were with mobile fax connected to mobile phone (5 min 23 s+/-3 min 5 s). In all ECGs transmitted except one the cardiac rhythm and ST-changes could be recognised. CONCLUSION: An advanced mobile phone is as fast and reliable as a conventional table fax in receiving ECGs. A mobile phone with advanced features is a practical tool for HEMS physicians who need to evaluate ECGs in the prehospital setting.

Cell Phone↗

Compliance with LTOT and consumption of mobile oxygen.

The aim of the study was to investigate compliance with long-term oxygen therapy (LTOT), the consumption of mobile oxygen and factors that might influence on these measures. The study included 182 patients with LTOT and 125 patients answered a questionnaire on daily activities. Information on arterial gas tension, lung function, and diagnosis was obtained from the medical file. Data on oxygen systems and the actual usage of oxygen were obtained from the oxygen suppliers. Seventy-six per cent of the patients had a concentrator and 35% had both stationary and mobile oxygen. Good compliance (use of oxygen > 15 h day-1) was seen in 65%. Of the tested factors, only mobile oxygen had an influence on the effective usage. Outdoor activity was reported in 65% of the patients. Only 48% of these patients had mobile units, while 21% of the home-bound patients had mobile units. Of the patients with mobile oxygen, only 39% used their mobile unit > 2 h week-1. Poorer usage of stationary oxygen was observed in patients with outdoor activity (2.4 hours day-1 less). Although only 16 (13%) patients reported a usage less than 15 h day-1, the actual consumption was less than 15 h day-1 in 29%. In conclusion, patients on LTOT tended to overestimate their oxygen usage. Acceptable compliance was observed in 65% of the patients. Only mobile oxygen had a significant impact on the overall compliance. As more patients had outdoor activities than expected, and as these activities had a negative impact on the usage of stationary oxygen, more attention must be paid on detecting outdoor activities. However, as fewer than half of the patients with outdoor activity and mobile oxygen used their mobile systems, there is a need for measures to improve compliance with mobile oxygen. Using lists referring to the actual usage and discussing the usage with the patients may improve the compliance and cost-benefit.

Adolescent↗

The low cycling status of mobilized peripheral blood CD34+ cells is not restricted to the more primitive subfraction.

Mobilized peripheral blood progenitor cells (PBPC) have been shown to differ qualitatively from bone marrow (BM) progenitors. The released progenitor cells are predominantly in G0/G1 and show a relatively high percentage of rhodamine dull cells. Within the BM these last two features are characteristic of the more primitive progenitors. Although the mobilized PB cells can give rise to long-term repopulation and thus contain stem cells, the frequency of stem cells is not much higher if long-term initiating cell (LTC-IC) assays are used. To determine whether quiescent stem cells are selectively released or the low-cycle status of PB progenitors is related to the release from the BM microenvironment, the cell cycle status and rhodamine content in the PB and BM during mobilization were studied and compared with steady-state BM. More differentiated and more primitive progenitors were separated based on differentiation markers and cloned in single cell assay. In mobilized PB 54% of the CD34+ cells (n=5) were rhodamine dull compared to 22% in steady-state BM (P=0.014) [n=6]. The percentage of CD34+ cells in the S/G2M phases of the cell cycle was 2.1% in the mobilized PB (n=11), and 18% in steady-state BM (n=11) [P=0.002]. During mobilization the fraction of cells in the S/G2M phase of the cell cycle was 16% in BM (n=7), similar to steady-state BM (P=0.34). The released progenitors represented a selection of BM progenitors, with significantly more primitive progenitors (CD34+/13+/33dim) and less lymphoid precursors (CD34+/19+). Within the more differentiated CD34+113+/33bright, myelomonocytic precursors, both in PB as well as in BM, the percentage S/G2M was relatively higher than in the CD34+/13+/33dim subfraction: in normal BM: median 18% vs 8% (P=0.006) [n=8]; in mobilized PB 3% vs 2% (P=0.03) [n=10]; and in BM during mobilization 24% vs 7% (P=0.01) [n=6]. The cycle status of mobilized PB progenitors was low both in the primitive and more differentiated subfractions. During the mobilization period the BM progenitors are cycling as in steady-state BM. The low-cycle status of the mobilized PB progenitors may be related to the loss of contact with the micro-environment.

Antigens, CD34↗

Five additional mobility and locomotor items to improve responsiveness of the FIM in wheelchair-dependent individuals with spinal cord injury.

STUDY DESIGN: Repeated-measures design. OBJECTIVES: To assess the validity and responsiveness of five additional mobility and locomotor (5-AML) items when used in conjunction with the Functional Independence Measure (FIM) for assessing the mobility and locomotor function of individuals with spinal cord injury (SCI). SETTING: Specialised acute spinal and rehabilitation units in Sydney, Australia. METHODS: A previously published scale comprising five key mobility and locomotor skills was further refined. The five items included a bed mobility and vertical (floor-to-chair) transfer item and three wheelchair propulsion items (pushing 200 m over flat ground, pushing up a ramp and negotiating a kerb). A total of 43 eligible patients with SCI (ASIA A-C impairment) admitted consecutively to two acute SCI units in Sydney between 1999 and 2002 were recruited, with four being lost to follow-up. Locomotor and mobility outcomes were measured at regular intervals for up to 6 months with the FIM and the 5-AML. Construct validity of the 5-AML was assessed by testing ability of items to discriminate between different impairment groups (tetraplegia and paraplegia). Item responsiveness was assessed by analysing ability to detect changes in mobility and locomotor function over time. Factor analysis techniques were used to test the hypothesis that the 5-AML, when used in conjunction with the FIM, provides a more sensitive measure of mobility and locomotor function than the FIM alone. RESULTS: The 5-AML items were shown to be valid and responsive, measuring aspects of 'real world' mobility and locomotor function not reflected by the FIM. The bed mobility item was highly responsive to change over time for the tetraplegic group, but quickly reached a ceiling in the paraplegic group. The vertical (floor-to-chair) transfer item showed greater responsiveness over time and less ceiling effect for the paraplegic group than any of the FIM locomotor or mobility items. The three wheelchair propulsion items better discriminated between people with tetraplegia and paraplegia, and were more sensitive to changes in locomotor ability over the 6-month period than FIM locomotor items. Results of a preliminary factor analysis indicated that the 5-AML items measure different aspects of mobility and locomotor function than the FIM. CONCLUSION: The 5-AML items, when used in conjunction with the FIM, provides better delineation of function between people with tetraplegia and paraplegia and provides a more responsive measure of change in function over time than the FIM alone.

Activities of Daily Living↗

Truncation mutants define and locate cytoplasmic barriers to lateral mobility of membrane glycoproteins.

The lateral mobility of cell membrane glycoproteins is often restricted by dynamic barriers. These barriers have been detected by measurements of fluorescence photobleaching and recovery (FPR) and barrier-free path (BFP). To define the location and properties of the barriers, we compared the lateral mobility, measured by FPR and BFP, of wild-type class I major histocompatibility complex (MHC) membrane glycoproteins with the lateral mobility of mutant class I MHC glycoproteins truncated in their cytoplasmic domains. Mutants with 0 or 4 residues in the cytoplasmic domain were as mobile as lipid-anchored class I MHC molecules, molecules whose lateral mobility is relatively unrestricted by barriers. In contrast, mobility of class I MHC molecules with 7-residue cytoplasmic domains was as restricted as mobility of class I molecules with full-length, 31-residue cytoplasmic domains. Though some of the difference between the mobilities of mutants with 4- or 0-residue domains and the other class I molecules may be due to differences in the net charge of the cytoplasmic domain, FPR measurements of the mobility of molecules with 7-residue domains show that length of the cytoplasmic domain has an important influence on the lateral mobility. Model calculations suggest that the barriers to lateral mobility are 2-3 nm below the membrane bilayer.

Amino Acid Sequence↗

Validity and responsiveness of the rivermead mobility index in stroke patients.

The Rivermead Mobility Index is used to measure mobility in patients with head injury or stroke. The purpose of the study was to examine construct validity, predictive validity, and the responsiveness of the Rivermead Mobility Index in stroke patients. Thirty-eight stroke inpatients participated in the study. The Rivermead Mobility Index, the Barthel Index, and the Berg Balance Scale were administered at admission to the rehabilitation ward and at discharge. The results showed that the Rivermead Mobility Index fulfilled the Guttman scaling criteria (coefficients of reproducibility > 0.9, coefficients of scalability > 0.7). The Rivermead Mobility Index scores were highly correlated with the Barthel Index scores (Spearman rs > 0.6) and the Berg Balance Scale scores (Spearman rs > = 0.8, all ps < 0.001). The Rivermead Mobility Index score at admission was closely correlated with the Barthel Index score at discharge (Spearman r = 0.77, p < 0.001). About 76% (29) of the subjects improved by more than 3 Rivermead Mobility Index points (median = 5) during their stay. The relationship between the change in score of the Rivermead Mobility Index and the Barthel Index was fair (Spearman r = 0.6, p < 0.001). These results indicate that the Rivermead Mobility Index is valid and sensitive to change over time. It is therefore a useful scale for the assessment of mobility in stroke patients.

Disability Evaluation↗

Mobility outcome following unilateral lower limb amputation.

This study investigated mobility outcome following unilateral trans-tibial or trans-femoral amputation. It was an observational study at the sub-regional amputee rehabilitation centre in Sheffield, UK. All unilateral trans-tibial or transfemoral amputees referred during the study period were included. The Harold Wood Stanmore mobility grade was recorded approximately one year following initial assessment at the centre. Of the 357 amputees referred, complete outcome data was available for 281 (78.7%). The mean age was 68 years (range 16-95), 70.1% were male, and the aetiology of the amputation was vascular or diabetic in 87.5% of cases. Trans-tibial amputations accounted for 50.5% and trans-femoral 49.5%. Almost all trans-tibial and trans-femoral amputees aged 50 and under achieved functional household and community mobility. Approximately 50% of the trans-tibial amputees aged over 50 years gained independent community mobility and around 60% household mobility. There was a significant worsening of community mobility rates with increasing age but for household mobility the differences did not reach statistical significance. Fewer than 25% of trans-femoral amputees aged over 50 achieved community mobility and around 50% achieved household mobility. There was a statistically significant deterioration in both community and household mobility levels with increasing age. This study concludes that mobility rates one year after prosthetic provision for unilateral trans-tibial and trans-femoral amputees worsen with increasing age at amputation and a higher level of amputation.

Adolescent↗

Standardized provocation of lumbar spine mobility: three methods compared by radiostereometric analysis.

STUDY DESIGN: By radiostereometric analysis (RSA), the intervertebral mobility was measured for the 3 most distal lumbar disc levels in 12 patients at 3 types of standardized provocation: changing body position from supine to standing, supine to standing with load, and supine to sitting. OBJECTIVE: To study the validity and intervertebral mobility response to 3 types of standardized provocation of the lower lumbar spine. SUMMARY OF BACKGROUND DATA: Active flexion-extension is used in clinical practice to detect pathologic kinematics in the lumbar spine. However, the actual mobility response is affected by variations in pain level and muscular spasm. Standardizing the examinations reduces these confounding factors, and brings the possibility to study intervertebral mobility over time and between individuals. A standardized method using traction-compression was introduced earlier but questioned due to the insufficient mobility provided. METHODS: After percutaneous application of tantalum indicators for RSA, the intervertebral mobility was measured for the 3 most distal lumbar disc levels in 12 adult patients with low back pain and disc degenerative disease. Each patient was examined in 4 separate positions: supine, normal standing, standing with sandbags (total weight 20 kg) on the shoulders, and sitting. The translatory movements induced by the patient changing position from supine to the other 3 positions were measured and the mobility response compared for the 3 types of provocation. RESULTS: The sagittal mobility induced by the sitting provocation was significantly higher than both the other types of provocation on all the 3 spinal levels measured. The same result was seen for the vertical translations except for the L3-L4 level, where the standing with load provocation was equal to sitting. Transverse translations were small and did not differ for the 3 types of provocation. CONCLUSION: The intervertebral mobility response provided in the lumbar spine when changing position from supine to sitting is more pronounced than both to standing and to standing with a 20 kg load. By the supine to sitting provocation, mean lumbar mobility is increased, and mobility can be revealed in some cases being stable in the other 2 situations. Combined with RSA, the method brings a refined possibility for studying lumbar spine kinematics.

Adult↗

In-vitro mobility of the lumbar spine.

As part of a systematic study of the spine between D11 and S1 the response to stress has been assessed by measuring radiologically the total and segmental mobility of 103 specimens. The method was shown to be reproducible to within 10% of total mobility. No significant sex difference was seen. Total mobility varied widely, but mean total mobility fell with age. All lumbar segments became less mobile up to the fifth decade. Between the fifth and the eighth decade the mobility of the fifth lumbar segment continued to fall, whereas other lumbar segments became more mobile. The mobility of each segment also varied widely, but the mean segmental mobility fell progressively from L5 to D11. However, this smooth pattern of movement was seen in only 16 cases, mostly adolescents and young adults. Among the remainder, in which movement was irregularly distributed, there were 7 cases (4 aged less than 30 years) in which the mobility of at least 1 segment was more than 2 standard deviations above the mean. The cause of this hypermobility was not evident radiologically. It is suggested that segments with abnormally high mobility may be at risk.

Adolescent↗

Neutrophil-derived MMP-9 mediates synergistic mobilization of hematopoietic stem and progenitor cells by the combination of G-CSF and the chemokines GRObeta/CXCL2 and GRObetaT/CXCL2delta4.

Mobilized peripheral blood stem cells (PBSCs) are widely used for transplantation, but mechanisms mediating their release from marrow are poorly understood. We previously demonstrated that the chemokines GRObeta/CXCL2 and GRObetaT/CXCL2Delta4 rapidly mobilize PBSC equivalent to granulocyte colony-stimulating factor (G-CSF) and are synergistic with G-CSF. We now show that mobilization by GRObeta/GRObetaT and G-CSF, alone or in combination, requires polymorphonuclear neutrophil (PMN)-derived proteases. Mobilization induced by GRObeta/GRObetaT is associated with elevated levels of plasma and marrow matrix metalloproteinase 9 (MMP-9) and mobilization and MMP-9 are absent in neutrophil-depleted mice. G-CSF mobilization correlates with elevated neutrophil elastase (NE), cathepsin G (CG), and MMP-9 levels within marrow and is partially blocked by either anti-MMP-9 or the NE inhibitor MeOSuc-Ala-Ala-Pro-Val-CMK. Mobilization and protease accumulation are absent in neutrophil-depleted mice. Synergistic PBSC mobilization observed when G-CSF and GRObeta/GRObetaT are combined correlates with a synergistic rise in the level of plasma MMP-9, reduction in marrow NE, CG, and MMP-9 levels, and a coincident increase in peripheral blood PMNs but decrease in marrow PMNs compared to G-CSF. Synergistic mobilization is completely blocked by anti-MMP-9 but not MeOSuc-Ala-Ala-Pro-Val-CMK and absent in MMP-9-deficient or PMN-depleted mice. Our results indicate that PMNs are a common target for G-CSF and GRObeta/GRObetaT-mediated PBSC mobilization and, importantly, that synergistic mobilization by G-CSF plus GRObeta/GRObetaT is mediated by PMN-derived plasma MMP-9.

Animals↗