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PubMed2005

[Subjective symptoms related to mobile phone use--a pilot study].

UNLABELLED: Research findings indicate that the use of mobile phones may lead to a number of symptoms such as headache, impaired concentration and memory, fatigue. In Poland this problem has not as yet been addressed by scientific studies. THE AIM: The present project was undertaken to investigate whether the symptoms of ill health reported by young people may be associated with the use of mobile phone. MATERIAL AND METHODS: A survey using a self-reported questionnaire was conducted among randomly selected university students in Lodz, Central Poland. The questionnaire was designed specifically for this study and contained items on health condition and complaints as well as on frequency of mobile phone use. The number of questionnaires necessary for the study was assessed using the simple random sample method. Out of the 160 copies distributed among the students, 140 (87.5%) were completed. Eventually, 117 questionnaires were subject to analysis; the data from respondents who reported health problems (neck trauma in a car accident, chronic sinusitis and arterial hypertension) were excluded. The following statistical methods were used to analyse questionnaire data: t-Student test for equal and unequal variances or F-Snedecor test for comparing parameters in two study groups, Fisher exact test for comparing frequency, and single and multiple logistic regression models for quantitative risk assessment of negative health outcomes in relation to exposure level and with control for confounders. The subjects were 61 (52.1%) males and 56 females (47.9%). RESULTS: Most of the subjects (62%) assessed their health condition as good, 31% as very good and 7% as fair. 70% complained of headache and 20% of dizziness. Impaired concentration occurred in 56% of respondents. Facial dermatitis was reported by 11%. The most prevalent symptom related to mobile phone use was the thermal sensation within the auricle and behind/around the ear. This was reported by 33 subjects (28.2%). Out of 82 subjects who complained of headache, only 8 (6.8%) related this symptom to mobile phone use. Only 10 subjects of 65 reporting impaired concentration thought it could be associated with their using a mobile phone. The symptoms and health complaints reported by the respondents in no case were the reason for a medical check-up or taking any medication. CONCLUSIONS: The large number of young people complaining of headache and impaired concentration calls for further research to investigate the underlying reasons. It cannot be excluded that one of them may be exposure to EMF emitted by mobile phone. The explanation should be sought through further experimental and epidemiologic studies.

Adult↗

PubMed2006

Comparison of high-grade and low-grade mobilization techniques in the management of adhesive capsulitis of the shoulder: randomized controlled trial.

BACKGROUND AND PURPOSE: In many physical therapy programs for subjects with adhesive capsulitis of the shoulder, mobilization techniques are an important part of the intervention. The purpose of this study was to compare the effectiveness of high-grade mobilization techniques (HGMT) with that of low-grade mobilization techniques (LGMT) in subjects with adhesive capsulitis of the shoulder. SUBJECTS: One hundred subjects with unilateral adhesive capsulitis lasting 3 months or more and a > or =50% decrease in passive joint mobility relative to the nonaffected side were enrolled in this study. METHODS: Subjects randomly assigned to the HGMT group were treated with intensive passive mobilization techniques in end-range positions of the glenohumeral joint, and subjects in the LGMT group were treated with passive mobilization techniques within the pain-free zone. The duration of treatment was a maximum of 12 weeks (24 sessions) in both groups. Subjects were assessed at baseline and at 3, 6, and 12 months by a masked assessor. Primary outcome measures included active and passive range of motion and shoulder disability (Shoulder Rating Questionnaire [SRQ] and Shoulder Disability Questionnaire [SDQ]). An analysis of covariance with adjustments for baseline values and a general linear mixed-effect model for repeated measurements were used to compare the change scores for the 2 treatment groups at the various time points and over the total period of 1 year, respectively. RESULTS: Overall, subjects in both groups improved over 12 months. Statistically significant greater change scores were found in the HGMT group for passive abduction (at the time points 3 and 12 months), and for active and passive external rotation (at 12 months). A statistically significant difference in trend between both groups over the total follow-up period of 12 months was found for passive external rotation, SRQ, and SDQ with greater change scores in the HGMT group. DISCUSSION AND CONCLUSION: In subjects with adhesive capsulitis of the shoulder, HGMTs appear to be more effective in improving glenohumeral joint mobility and reducing disability than LGMTs, with the overall differences between the 2 interventions being small.

Bursitis↗

PubMed1991

Protease priming of neutrophil superoxide production. Effects on membrane lipid order and lateral mobility.

Phagocyte superoxide (O2-) response is primed by a variety of physiologic compounds including the neutrophil secretory proteases cathepsin G and elastase. To study whether protease priming of neutrophil O2- response is related to changes in membrane physical state, we examined enzyme effects on the order and lateral mobility of lipid probes in intact neutrophil membranes. Exposure to cathepsin G (5 micrograms/ml) or elastase (10 micrograms/ml) caused a significant decrease in fluorescence anisotropy of the probe trimethylammonium diphenylhexatriene in neutrophil plasma membranes (0.279 to 0.256 for cathepsin G, 0.274 to 0.256 for elastase, p less than 0.02 for both), indicating a decrease in phospholipid chain order in the surface membrane bilayer. Cathepsin G and elastase also caused significant increases in membrane lipid lateral mobility as measured by excimer formation of the fluorescent probe 1-pyrenedecanoic acid (for cathepsin G, a 107% increase, and for elastase, a 44% increase in excimer/monomer fluorescence ratio, p less than 0.001). Enzyme effects on membrane structure were dependent on intact proteolytic activity, and were cell specific; the proteases had no effect on lipid order or lateral mobility in liposomes. In corollary studies, the possible association between the physical state of the polymorphonuclear leukocyte membrane and O2- generation was analyzed with the membrane modifying compounds, linoleic acid, ethanol, and cholesterol. Cell exposure to linoleic acid (1 microM) caused a significant decrease in lipid order and an increase in lipid lateral mobility along with increased O2- production to N-formyl-Met-Leu-Phe (fMLP) (191%) and phorbol myristate acetate (PMA) (39%), p less than 0.02 for each. 3 mM ethanol also augmented O2- response to fMLP (31%) and PMA (48%) and caused a significant decrease in lipid order, but did not affect lipid lateral mobility. Treatment with cholesteryl hemisuccinate (100 micrograms/ml) resulted in increased lipid order and decreased lipid lateral mobility, as well as decreased neutrophil superoxide response to fMLP (-61%, p less than 0.001) and PMA (-50%, p less than 0.02). We then examined whether modulation of membrane physical state may explain the mechanism of action of a known priming agent by studying the effects of low concentrations of a diacylglycerol. Cells treated with 10 microM 1-oleoyl-2-acetyl-sn-glycerol had a greater than 8-fold increase in superoxide response to fMLP (p less than 0.001) while demonstrating a significant decrease in lipid order (0.289 to 0.281, p less than 0.01) and a 50% increase in lipid lateral mobility (p less than 0.001).(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗

PubMed2006

Are scores on balance screening tests associated with mobility in older adults?

PURPOSE: To examine associations between measures of static and dynamic balance and performance of mobility tasks in older adults. METHODS: A cross-sectional analysis from 95 community dwelling participants (mean age 80.9 years, range 65 -03 years). Participants performed tests of static (tandem stance) and dynamic (360 degrees turn) balance and mobility (walking speed and timed chair rise). Associations among balance and mobility measures were examined using correlation and logistic regression. RESULTS: Static and dynamic balance were moderately associated (r = -.462). Relationships between dynamic balance and mobility were stronger than those between static balance and mobility. The association between dynamic balance and walking speed was particularly strong (r = -.701 ). Using logistic regression, age, and balance performance were significant predictors for outcomes of walking speed (dichotomized to < .0 m/s, >/= .0 m/s), and timed chair rise (dichotomized to </= 3.6 s, > 3.6 s). Faster 360 degrees turn times were independently associated with faster walking speed and chair rise time. CONCLUSION: Mobility tasks require both dynamic and static balance. As falls are a major health risk for older adults, including brief assessments of dynamic and static balance in the examination of older adults provides valuable information about physical function and mobility.

Aged↗

PubMed2006

The history of mobile-bearing total knee replacement systems.

The use of a mobile-bearing knee system is routine in modern total knee arthroplasty (TKA). There are indications for use of a mobile-bearing TKA for a growing number of patients. The design, however, was not always well appreciated. Fears of perioperative difficulties and lack of understanding of the design principles limited the acceptance of mobile-bearing technology. Recent evidence has shown that use of mobile-bearing prostheses in TKA has increased, and today, nearly three decades after its introduction, the mobile-bearing design remains relavent and important. The theories behind the design of mobile-bearing prostheses have shown in clinical practice what many already believed to be true: mobile-bearing TKA, when performed correctly, is reliable, and capable of providing substantial benefit for patients.

History, 20th Century↗

PubMed1991

[Limitations of joint mobility in patients with type 1 diabetes mellitus].

BACKGROUND: To assess limitation of joint mobility in patients with type I diabetes mellitus and to evaluate its relation with retinopathy, joint mobility was prospectively assessed in 96 diabetic patients and 68 healthy controls. METHODS: Joint mobility was explored with the praying maneuver and the measurement in mobility degrees of the third and fifth metacarpophalangeal joints, wrists and elbows. The degree of metabolic control was assessed with the mean glycosylated hemoglobin in the last two years. Retinopathy was investigated with direct funduscopy. The results were statistically evaluated with chi-square and Student's t tests and the linear coefficient. RESULTS: A reduced joint mobility was found in 41 diabetics and 5 controls (p less than 0.0001). The reduction in joint mobility was related with the patients' age but not with the degree of metabolic control. 85% of diabetics with joint involvement had retinopathy of some degree. CONCLUSIONS: A limited joint mobility is a common complication of type I diabetes mellitus. The demonstration of this abnormality in diabetic patients might represent a first and simple marker of microangiopathy.

Adolescent↗

PubMed1990

Lumbar sagittal mobility and low back symptoms in patients treated with manipulation.

The relationship between lumbar sagittal mobility and symptoms was explored in a 1-year prospective study of 55 patients undergoing manipulative treatment. A significant increase in mean mobility was found to occur in the 1st month, together with a concomitant significant decrease in mean pain values; symptoms continued to decrease thereafter, but mobility remained unchanged. More detailed analysis of the data revealed that symptomatic improvement was as common in patients with unaltered or reduced mobility as it was in those who showed an increase; changes in mobility at 1 month had no predictive value for symptomatic status at 1 month or 1 year. It is concluded that if any benefits actually result from manipulative therapy they are not a direct function of increased overall lumbar sagittal mobility. It remains possible that manipulation may influence other mobility parameters, such as coupled motions, so future studies should be directed toward investigation of three-dimensional movement patterns.

Adult↗

PubMed1990

Leukotriene D4 and E4 induce transmembrane signaling in human epithelial cells. Single cell analysis reveals diverse pathways at the G-protein level for the influx and the intracellular mobilization of Ca2+.

Leukotrienes are recognized as important mediators of the inflammatory process. Recently, increasing attention has been paid to the role of noninflammatory cells in the regulation of the inflammatory process. To further increase our knowledge of this matter we have, in the present study, investigated leukotriene-induced Ca2+ signaling, using a single cell technique in a human epithelial cell line, Intestine 407. It was evident that both LTD4 and LTE4, at physiological concentrations (10 nM), triggered rapid and pronounced cytosolic free Ca2+ transients, due to both influx across the plasma membrane and intracellular mobilization. Preincubation with pertussis toxin (1200 ng/ml) decreased the level of agonist-induced Ca2+ transients to an extent similar to that caused by depletion of extracellular Ca2+, suggesting that the toxin affected the influx but not the intracellular mobilization of Ca2+. Indeed, by using the Mn2+ quenching technique, it could be shown that pertussis toxin totally inhibited the influx of Ca2+. The fact that, even after pertussis toxin treatment, direct G-protein activation by AIF4- was still able to trigger a cytosolic free Ca2+ transient, indicates that, in these cells, G-proteins (GTP-binding proteins) that are insensitive to pertussis toxin are capable of mediating a Ca2+ signal. In order to test the idea that such G-proteins regulate mobilization of intracellular Ca2+ induced by LTD4 and LTE4, we electropermeabilized and preincubated the Intestine 407 cells with guanosine-5'-O-(2-thiodiphosphate) (GDP beta S), let them reseal, and, after loading with fura2, investigated the effects on agonist-stimulated Ca2+ signaling. Electropermeabiization and resealing alone did not significantly affect the Ca2+ responses triggered by LTD4 or LTE4. Addition of GDP beta S, in the presence of extracellular Ca2+, reduced the Ca2+ responses by approximately 60-70%. In Ca2(+)-depleted medium, GDP beta S also impaired the LTD4-induced response by 65%, however, it had no effect on the Ca2+ response induced by LTE4. In conclusion, LTD4 and LTE4 trigger cytosolic free Ca2+ signaling in a human epithelial cell line by causing both an influx of Ca2+ and mobilization of intracellular Ca2+. The Ca2(+)-signaling mechanism appears to consist of dual pathways, since the influx is regulated by a pertussis toxin-sensitive G-protein, but, the mobilization of Ca2+ is not. Furthermore, our data suggest that the LTD4-induced mobilization is regulated by a pertussis toxin-insensitive G-protein whereas the LTE4-induced mobilization is relatively insensitive to both pertussis toxin and GDP beta S.

Aluminum↗

PubMedDate not supplied

Predicting elderly patients' mobility using fall history and physician assessment.

This study tested whether a patient's history of falls or an office clinician's general assessment can predict which ambulatory elderly patients will do poorly on mobility testing. Ambulatory patients making routine visits who were age 65 or older, mentally competent, and not acutely ill were eligible. Fifty-two (91%) of these patients participated by completing a fall history questionnaire and undergoing mobility testing. After the visit, the attending physician estimated how the patient would score on the mobility test. Twelve (23%) of the patients reported falls and seven (13.5%) reported fall injuries in the preceding year. Both fall history and physician estimate of mobility score significantly correlated with the measured mobility score. Only the physician estimate of mobility score, however, had adequate sensitivity (94.4%) and specificity (82.4%) to be clinically useful. This estimate will allow the clinician to selectively apply mobility testing to those patients likely to score poorly.

Accidental Falls↗

PubMed1984

Analysis of electrophoretic mobility histogram of mouse thymocytes during tumour development.

The population of medullary thymocytes without peanut agglutinin (PNA) receptor consisted of two groups: Lyt-1+ .2- cells with a high mobility of 1.0 micrometer/sec/V/cm, and Lyt-1+ .2+ cells with a low mobility of 0.7 micrometer/sec/V/cm. Also used were cortical thymocytes with PNA receptor: these were Lyt-1+ .2+ cells, having low mobility. In C3H/He mice bearing plasmacytoma X5563, a low mobility peak appeared in the histograms of peripheral lymphocytes. In contrast, a high mobility peak appeared in the histograms of thymocytes. Using full automated analytical instrumentation, it was determined that the appearance of high mobility cells during tumour growth strongly correlated with the decreased proportion of low mobility cells in thymus.

Animals↗

PubMed1980

Hemopathologic consequences of protracted gamma irradiation: alterations in granulocyte reserves and granutocyte mobilization.

Aplastic anemia and myelogenous leukemia are prominent pathologic effects in beagles exposed to continuous, daily, low-dose gamma irradiation. In the present work, granulocyte reserves and related mobilization functions have been sequentially assessed by the endotoxin stress assay during the preclinical and clinical phases of these hemopoietic disorders. Characteristic patterns of granulocyte reserve mobilization are described that reflect given stages of pathologic progression. For radiation-induced leukemia, a five stage pattern has been proposed. In contrast, a simple pattern of progressive, time-dependent contraction of granulocyte reserves and mobilization capacity was noted in the development of terminal aplastic anemia. Early preclinical phases of radiation-induced leukemia appear to involve an extensive depletion of the granulocyte reserves ((phase I) during the first approximately 200 days of exposure followed by a partial renewal of the reserves and associated mobilization functions approximately 200 and 400 days (phase II). Sustained, subnormal granulocyte mobilizations (phase III) following endotoxin stress typify the responses of dogs during the intermediate phase, whereas late preclinical, preleukemic stages (phase IV) are characterized by a further expansion of the reserves and in the mobilization capacities, particularly of the less mature granulocytes. Such late alterations in the pattern of granulocyte mobilization, together with other noted cellular aberrancies in the peripheral blood and marrow, appear to indicate leukemia (phase V) onset.

Anemia, Aplastic↗

PubMedDate not supplied

[Equilibrium intramolecular mobility in proteins].

The critical analysis of available information on equilibrium intramolecular mobility in proteins is performed and an attempt is made to systematize it in relation to characteristic times tau, probability and spatial scale. We propose to discriminate fast (tau less than 10(-6) s) and slow (tau greater than 10(-6) s) mobility. The methods are considered for investigating fast mobility (X-ray analysis temperature-dependent factor, broadening of absorption spectra, thermal perturbation difference spectra and thermal ring-current shifts of 1H-NMR, fluorescence dipolar relaxation and quenching, 13C-NMR spin-lattice relaxation times and nuclear Overhauser enhancement and others) and the principal results obtained. Fast mobility is widely spread within the molecules. Its existence results in a population of dynamic microstates, the distribution of which depends on local packing density and secondary bonding. The fast movements are local and of very small activation energies. tau depends on the group size and are much longer than those of diffusion in simple liquids. Therefore, this kind of mobility may be characterized as a limited diffusion process in a medium with high and nonuniform viscosity. The significance of the fast mobility for the protein function is discussed. No function significant transglobular change of protein conformation could be obtained by subnanosecond, fast movements, but they depend on the level of "viscosity' of protein interior, produced by fast mobility. The fast dynamic microstates results in distribution of activation parameters for protein reactions.

Kinetics↗

PubMed1982

The hydrophobic-hydrophilic balance of bile salts. Inverse correlation between reverse-phase high performance liquid chromatographic mobilities and micellar cholesterol-solubilizing capacities.

To examine quantitatively the hydrophobic-hydrophilic properties of bile salts, we determined the reverse-phase high performance liquid chromatographic (HPLC) mobilities of monomeric bile salt solutions and the equilibrium cholesterol-solubilizing capacities of 100 mM micellar solutions. Studies with the common bile salts (ursodeoxycholate, UDC, cholate, C, chenodeoxycholate, CDC, and deoxycholate, DC) demonstrated that HPLC mobility, which correlates with hydrophilicity, was markedly influenced by both position and orientation, in addition to number, of hydroxyl functions, in that mobility decreased in the order UDC > C > CDC > DC. Conjugation of the bile salt was also important, in that the HPLC mobility of the taurine (T)-conjugates was greater than the glycine (G)-conjugates which in turn was greater than that of the free bile salts. Equilibrium micellar cholesterol solubilities were also influenced by bile salt structure and correlated inversely with hydrophilicity, in that solubility decreased in the order DC > CDC > C > UDC with free bile salts > G-conjugates > T conjugates. For each bile salt series, double logarithmic plots of the cholesterol-solubilizing capacities expressed in mole fraction units versus the HPLC retention factors (k') gave linear relationships. Linear regression equations were employed to predict the equilibrium cholesterol-solubilizing capacities of a number of less common bile salts from their HPLC retention factors. Each theoretical value agreed closely with that derived entirely by experiment. A comparison of the HPLC mobilities of the less common bile salts with the more common species revealed that not only were sulfate and oxo substituents more hydrophilic than alpha-oriented hydroxyl functions, but, in the dihydroxy species, a single equatorial hydroxyl function such as in UDC (3alpha,7beta) and in hyodeoxycholate (3alpha,6alpha) was more hydrophilic than two or three hydroxyl functions at 3, 7, and/or 12alpha (axial) positions. These studies taken together suggest that reverse-phase HPLC mobility and equilibrium cholesterol-solubilizing capacities are inverse functions of each other and correlate closely with the hydrophilicity of bile salt molecules. In addition, the evidence here deduced further strengthens our recent deductions based on an evaluation of a number of other physical-chemical properties (Carey, M. C., J-C. Montet, M. C. Phillips, M. J. Armstrong, and N. A. Mazer, 1981. Biochemistry. 20: 3637-3648.) that cholesterol may be solubilized in micellar bile salt solutions by both hydrophobic and hydrophilic association with the external ("hydrophilic") surface of bile salt micelles rather than with the hydrophobic surface of the micelle's interior.-Armstrong, M. J., and M. C. Carey. The hydrophobic-hydrophilic balance of bile salts. Inverse correlation between reverse-phase high performance liquid chromatographic mobilities and micellar cholesterol-solubilizing capacities.

Bile Acids and Salts↗

PubMed1982

Joint mobility in children: a population study.

The mobility of five joint pairs ( metacarpophalangeal, wrist, elbow, knee and ankle) was investigated in 3,000 mixed school children of Bahia, Brazil. A sampling method was designed to assure an equal number of fifty children in the smallest classes, when age, race and sex were held constant. Race was classified in five subgroups to assess the proportion of Black admixture. Multiple regression was carried out to analyze the data. The results showed a consistent effect of age on decreasing joint mobility, The effect of race was also on decreasing mobility of wrist, elbow and ankle; the darker the child, the less the joint mobility. However, the effect of sex showed no general consistency; for wrist, elbow and knee the girls had more mobility than the boys; for the ankle the boys had more mobility than the girls; and the metacarpophalangeal joint there was no sex difference. The complexity of multicausal effects on joint mobility are discussed considering the simultaneous interplay of biological and environmental actions.

Adolescent↗

PubMed1980

Mechanism of the linkage between te electrophoretic mobility and oxygen uptake of ascites tumor cells.

Electrophoretic mobility, glucose metabolism, and oxygen uptake were studied in three leukemic and in four nonleukemic strains of ascites tumor cells. The cells differed markedly in mobility. This variation was related neither to cell growth nor to rates of endogenous respiration and aerobic glycolysis. The nonleukemic tumor cells showed higher mobility than did the leukemic cells. Additional increases in mobility appear to be related to suppressed oxygen uptake, which results from the addition of glucose or 0.05 mM 2,4-dinitrophenol. The augmented negative surface charge does not seem to be related to those ionogenic sites susceptible to neuraminidase. However, RNase treatment of the nonleukemic tumor cell does reveal the presence in their surface membrane of negatively charged sites susceptible to this enzyme. Such RNase-susceptible ionogenic sites presumably redistribute at the cell surface membrane from the inner sites as a response to suppressed oxygen uptake. This results in a higher negative surface charge and increased mobility. The leukemic cells, on the other hand, did not show any change in oxygen uptake or mobility in the presence of glucose. Moreover, the reduced rate of oxygen uptake induced by the addition of 0.05 mM 2,4-dinitrophenol did not result in any significant alterations in mobility. This is consistent with the observation that the ionogenic sites susceptible to RNase do not appear at the surface of the leukemic cells upon suppressed oxygen uptake. The leukemic cells have thus been shown to differ from the nonleukemic tumor cells in certain aspects of their glucose metabolism as well as in the electrophoretic properties of their surface.

Animals↗

PubMed1994

Mobilization of tumor cells and hematopoietic progenitor cells into peripheral blood of patients with solid tumors.

Peripheral blood progenitor cells (PBPCs) are increasingly used for autografting after high-dose chemotherapy. One advantage of PBPCs over the use of autologous bone marrow would be a reduced risk of tumor-cell contamination. However, the actual level of tumor cells contaminating PBPC harvests is poorly investigated. It is currently not known whether mobilization of PBPCs might also result in mobilization of tumor cells. We evaluated 358 peripheral blood samples from 46 patients with stage IV or high-risk stage II/III breast cancer, small cell (SCLC) or non-small cell (NSCLC) lung cancer, as well as other advanced malignancies for the detection of epithelial tumor cells. Monoclonal antibodies against acidic and basic cytokeratin components and epithelial antigens (HEA) were used in an alkaline phosphatase-anti-alkaline phosphatase assay with a sensitivity of 1 tumor cell within 4 x 10(5) total cells. Before initiation of PBPC mobilization, circulating tumor cells were detected in 2/7 (29%) patients with stage IV breast cancer and in 2/10 (20%) patients with extensive-disease SCLC, respectively. In these patients, an even higher number of circulating tumor cells was detected after chemotherapy with VP16, ifosfamide, and cisplatin (VIP) followed by granulocyte colony-stimulating factor (G-CSF). This approach has previously been shown to be highly effective in mobilizing PBPCs. In the 42 patients without circulating tumor cells during steady state, tumor cells were mobilized in 9/42 (21%) patients after VIP+G-CSF induced recruitment of PBPCs. The overall incidence of tumor cells varied between 4 and 5,600 per 1.6 x 10(6) mononuclear cells analyzed. All stage IV breast cancer patients and 50% of SCLC patients were found to concomitantly mobilize tumor cells and PBPCs. Kinetic analyses showed two patterns of tumor cell recruitment depending on the presence or absence of bone marrow disease: (1) early after chemotherapy (between days 1 and 7) in patients without marrow infiltration, and (2) between days 9 and 16 in patients with marrow infiltration, ie, within the optimal time period for the collection of PBPCs. We show that there is a high proportion of patients with circulating tumor cells under steady-state conditions, and in addition a substantial risk of concomitant tumor cell recruitment upon mobilization of PBPCs, particularly in stage IV breast cancer patients with bone marrow infiltration. The biologic and clinical significance of this finding is unknown at present.

Adult↗

PubMed1995

[Effect of ligands on rotational mobility of Na,K-ATPase].

Phosphorescence anisotropy of eosin-5'-isothiocyanate labelled Na,K-ATPase purified from duck salt glands has been studied. The initial anisotropy value is 0.235 +/- 0.015 (room temperature) and does not depend on the enzyme conformation (sodium or potassium). The experimental curve is fitted into a two-exponential curve with residual term, the fast component corresponds to the rotational mobility of the functional unit of Na,K-ATPase (promoter), while the slow one--to that of larger associates. In the presence of ligands modifying the conformational state of Na,K-ATPase (sodium, potassium, ATP) the rotational mobility of the fast component does not change in contrast with the slow one. A comparison of the enzyme rotational mobility in the presence of ligands simulating different steps of hydrolytic cycle suggests that interprotomer interactions are changed in the course of hydrolytic cycle: the fraction of larger associates increases at the step of the enzyme interactions with potassium ions, whereas their mobility in the bilayer enhances sharply after interaction with ATP. In the presence of the 2% non-ionic detergent, C12E9, the initial anisotropy value decreases down to 0.1; the residual term disappears thereby, while the curve is still two-exponential. However, the difference in the rotational mobility of sodium and potassium conformers diminishes. At the same time, the ratios between protomers and oligomers in the presence of sodium and potassium become approximated. This indicates that in the presence of the detergent high molecular weight associates are solubilized, the mobility of the both protomers and oligomers of Na,K-ATPase increases, while the difference between the mobilities of sodium and potassium conformers is disappeared.

Animals↗

PubMed1994

Mobile telephones interfere with medical electrical equipment.

Electromagnetic interference in medical electrical equipment has not been a serious problem in recent years even with the proliferation of analogue mobile phones and two-way handheld radios. With the introduction of GSM digital mobile phones into Australia we have conducted measurements and found that, within 2m, the electric fields from digital mobile phones can exceed the immunity level of 7 V/m recommended by the US Food and Drug Administration (FDA) for medical electrical equipment. Current analogue mobile phones were shown to produce electric fields that exceed the 7 V/m level only at relatively shorter distances. In another test, both analogue and digital mobile phones were operated close to a range of typical medical electrical equipment. It was found that existing equipment generally meets the FDA standard, but digital mobile phones caused a variety of artefacts and alarm conditions. This problem must be addressed by the medical engineering profession; in the meantime, nursing and other staff should be educated to recognise these problems and restrictions must be placed upon the use of mobile phones in hospitals.

Electromagnetic Fields↗