Fast absolute 3D CGO-based electrical impedance tomography on experimental tank data

Objective.To present the first 3D CGO-based absolute EIT reconstructions from experimental tank data.Approach.CGO-based methods for absolute EIT imaging are compared to traditional TV regularized non-linear least squares reconstruction methods. Additional robustness testing is performed by considering incorrect modeling of domain shape.Main Results.The CGO-based methods are fast, and show strong robustness to incorrect domain modeling comparable to classic difference EIT imaging and fewer boundary artefacts than the TV regularized non-linear least squares reference reconstructions.Significance.This work is the first to demonstrate fully 3D CGO-based absolute EIT reconstruction on experimental data and also compares to TV-regularized absolute reconstruction. The speed (1-5 s) and quality of the reconstructions is encouraging for future work in absolute EIT.

3D ELECTRICAL IMPEDANCE TOMOGRAPHY RECONSTRUCTIONS FROM SIMULATED ELECTRODE DATA USING DIRECT INVERSION texp AND CALDERÓN METHODS

The first numerical implementation of a t ^exp method in 3D using simulated electrode data is presented. Results are compared to Calderón's method as well as more common TV and smoothness regularization-based methods. The t ^exp method for EIT is based on tailor-made non-linear Fourier transforms involving the measured current and voltage data. Low-pass filtering in the non-linear Fourier domain is used to stabilize the reconstruction process. In 2D, t ^exp methods have shown great promise for providing robust real-time absolute and time-difference conductivity reconstructions but have yet to be used on practical electrode data in 3D, until now. Results are presented for simulated data for conductivity and permittivity with disjoint non-radially symmetric targets on spherical domains and noisy voltage data. The 3D t ^exp and Calderón methods are demonstrated to provide comparable quality to their 2D counterparts, and hold promise for real-time reconstructions due to their fast, non-optimized, computational cost.

Prospective Ultrasound Screening of Men With Cerebrovascular Disease for Abdominal Aortic Aneurysms

BACKGROUND

The prevalence of abdominal aortic aneurysms is higher in population with other vascular comorbidities, especially among men. Utility of screening among patients with cerebrovascular disease is unclear.

OBJECTIVE

To determine the prevalence of abdominal aortic aneurysm in male patients with diagnosed cerebrovascular disease manifested by transient ischemic attack or stroke.

METHODS

Between May 2013 and May 2014, all consecutive male patients undergoing carotid ultrasound in single tertiary center with a catchment area of 179,000 inhabitants were evaluated for ultrasound screening of abdominal aortic aneurysm. Abdominal aortic aneurysm was defined as maximum diameter of infrarenal aorta 30 mm or more.

RESULTS

Of 105 (n = 105) consecutively evaluated male patients, only 69% (n = 72) were eligible for the study and underwent aortic screening. Reason for ineligibility was most often poor general medical condition (n = 29). Mean age of screened patients was 66 years (SD 9.8 years). Half of the screened patients suffered stroke (n = 36). The incidence of abdominal aortic aneurysm was 5.6% (n = 4). All found abdominal aortic aneurysms were small and did not require immediate surgical intervention. During a follow-up period of over 4 years, none of the aneurysms exhibited tendency for growth.

CONCLUSIONS

The male population with cerebrovascular disease is comorbid and frail. Only, moderate prevalence of abdominal aortic aneurysms can be found in this subpopulation.

Spectroscopic properties of nuclear skyrme energy density functionals

We address the question of how to improve the agreement between theoretical nuclear single-particle energies (SPEs) and observations. Empirically, in doubly magic nuclei, the SPEs can be deduced from spectroscopic properties of odd nuclei that have one more or one less neutron or proton. Theoretically, bare SPEs, before being confronted with observations, must be corrected for the effects of the particle vibration coupling (PVC). In the present work, we determine the PVC corrections in a fully self-consistent way. Then, we adjust the SPEs, with PVC corrections included, to empirical data. In this way, the agreement with observations, on average, improves; nevertheless, large discrepancies still remain. We conclude that the main source of disagreement is still in the underlying mean fields, and not in including or neglecting the PVC corrections.

Late-onset spinal motor neuronopathy - a common form of dominant SMA

We previously described two Finnish families with a new autosomal dominant late-onset spinal motor neuronopathy that was mapped to chromosome 22q11.2-q13.2. In the current screening study of 43 lower motor neuron disease patients from Finland and Sweden, we identified 26 new late-onset spinal motor neuronopathy patients sharing the founder haplotype. In addition to the main symptoms and signs: painful cramps, fasciculations, areflexia and slowly evolving muscle weakness, new features such as mild bulbar findings, were identified. The disease is relatively benign in terms of life expectancy and rate of disability progression, and it is therefore noteworthy that three patients were initially misdiagnosed with ALS. Significant recombinants in this new patient cohort restricted the disease locus by 90% to 1.8Mb. Late-onset spinal motor neuronopathy seems not to be very rare, at least not in Finland, with 38 patients identified in a preliminary ascertainment.

Late-onset lower motor neuronopathy: a new autosomal dominant disorder

OBJECTIVE

Characterization of a new type of late-onset autosomal dominant lower motor neuron disease.

METHODS

Patients from 2 families underwent detailed neurologic, electrophysiologic, muscle biopsy, and laboratory investigations. MRI of lower limbs was performed in selected patients. DNA samples from leukocytes were used for molecular genetic linkage studies.

RESULTS

First symptoms were muscle cramps and fasciculations after age 25-30, followed by a slowly progressive proximal and distal weakness without overt atrophy during the first decades of symptoms. Nerve conduction velocities were within normal range and EMG showed widespread neurogenic alterations. Muscle biopsy revealed characteristic neurogenic findings: fiber type grouping and group atrophy. MRI showed diffuse fatty-degenerative changes, marked in medial gastrocnemius.

CONCLUSION

Exactly the same clinical phenotype has not previously been described, and linkage studies showed exclusion of known chromosomal loci for hereditary motor neuropathies, suggesting the disease we report may represent a new disorder.

An adaptive multimeme algorithm for designing HIV multidrug therapies

This paper proposes a period representation for modeling the multidrug HIV therapies and an Adaptive Multimeme Algorithm (AMmA) for designing the optimal therapy. The period representation offers benefits in terms of flexibility and reduction in dimensionality compared to the binary representation. The AMmA is a memetic algorithm which employs a list of three local searchers adaptively activated by an evolutionary framework. These local searchers, having different features according to the exploration logic and the pivot rule, have the role of exploring the decision space from different and complementary perspectives and, thus, assisting the standard evolutionary operators in the optimization process. Furthermore, the AMmA makes use of an adaptation which dynamically sets the algorithmic parameters in order to prevent stagnation and premature convergence. The numerical results demonstrate that the application of the proposed algorithm leads to very efficient medication schedules which quickly stimulate a strong immune response to HIV. The earlier termination of the medication schedule leads to lesser unpleasant side effects for the patient due to strong antiretroviral therapy. A numerical comparison shows that the AMmA is more efficient than three popular metaheuristics. Finally, a statistical test based on the calculation of the tolerance interval confirms the superiority of the AMmA compared to the other methods for the problem under study.

Effects of hormone replacement therapy and high-impact physical exercise on skeletal muscle in post-menopausal women: a randomized placebo-controlled study

An age-related decline in muscle performance is a known risk factor for falling, fracture and disability. In women, a clear deterioration is observed from early menopause. The effect of hormone replacement therapy (HRT) in preserving muscle performance is, however, unclear. This trial examined the effects of a 12-month HRT and high-impact physical exercise regimen on skeletal muscle in women in early menopause. A total of 80 women aged 50-57 years were assigned randomly to one of four groups: exercise (Ex), HRT, exercise+HRT (ExHRT) and control (Co). The exercise groups participated in a high-impact training programme. The administration of HRT (oestradiol/noretisterone acetate) or placebo was carried out double-blind. Knee extension torque and vertical jumping height were evaluated. Lean tissue cross-sectional area (LCSA) and the relative proportion of fat within the muscle compartment were measured for the quadriceps and lower leg muscles. The ExHRT group showed significant increases in knee extension torque (8.3%) and vertical jumping height (17.2%) when compared with the Co group (-7.2%). Vertical jumping height also increased after HRT alone (6.8%). The LCSA of the quadriceps was increased significantly in the HRT (6.3%) and ExHRT (7.1%) groups when compared with the Ex (2.2%) and Co (0.7%) groups. Lower leg LCSA was also increased in the ExHRT group (9.1%) when compared with the Ex (3.0%) and Co (4.1%) groups. In addition, the increase in the relative proportion of fat in the quadriceps in the Co group (16.6%) was significant compared with those in the HRT (4.9%) and ExHRT (-0.6%) groups. Thus, in post-menopausal women, muscle performance, muscle mass and muscle composition are improved by HRT. The beneficial effects of HRT combined with high-impact physical training may exceed those of HRT alone.

Comparison of erythritol and xylitol saliva stimulants in the control of dental plaque and mutans streptococci

The effect of 2-month usage of saliva-stimulating pastils containing either erythritol or xylitol was studied in a cohort of 30 subjects assigned to the respective polyol groups (n = 15). The daily consumption level of both polyols was 5.2 g, used in 5 daily chewing episodes. The mean weight of total plaque mass (collectable during a standard period of 3 min from all available tooth surfaces) was reduced significantly in the xylitol-group, while no such effect was observed in the erythritol-group. This reduction in plaque mass was accompanied by a significant reduction in the turbidity readings (A(660)) of aqueous plaque suspensions; no such effect was observed in the erythritol-group. However, plaque protein levels did not differ between baseline and endpoint in either polyol group. The plaque and salivary levels of Streptococcus mutans and plaque levels of total streptococci were reduced significantly in the xylitol-group, while no such effect was detected in the erythritol-group. However, either polyol regimen had no effect on plaque levels of S. sobrinus. The results suggest that systematic use of xylitol-containing saliva stimulants may be more effective in controlling some oral-hygiene-related and caries-associated parameters than similar use of erythritol-containing products. The results also speak for a special relationship between xylitol and S. mutans. However, owing to the great potential of erythritol as a caries-reducing agent -- based on the tetritol nature of erythritol -- the present laboratory results should be considered preliminary and subject to verifying clinical studies.

Lymph flow dynamics in exercising human skeletal muscle as detected by scintography

1. The effects of dynamic and isometric muscle contractions on the lymph flow dynamics in human skeletal muscle were studied with a scintographic method. 2. Radioactively labelled human serum albumin (99mTc-HSA) was injected bilaterally into the vastus lateralis muscles of eight men (n = 16), four of whom had had an endurance training background. The subjects performed 100 submaximal contractions in 10 min as (i) dynamic knee extensions (CONS), (ii) isometric contractions with the knees at full extension (IMExt), or (iii) isometric contractions with knees fixed at 90 deg angle flexion (IMFlex). The exercises were separated by 65 min periods in supine rest. The level of radioactivity at the injection site was monitored by a gamma-camera, and the clearance rate of radioactivity (CR) was calculated as the fractional decrease during the periods of interest (CR unit = % min-1). 3. The clearance rate was low during the rest periods (0.04 +/- 0.05% min-1), though higher in the trained than in the sedentary subjects (0.06 +/- 0.05 vs. 0.03 +/- 0.03% min-1; P = 0.008). Exercise increased the clearance rate three- to sixfold, to 0.16 +/- 0.16% min-1 during CONS, 0.20 +/- 0.15% min-1 during IMExt and 0.09 +/- 0.11% min-1 during IMFlex. There were no differences between the subject subgroups. 4. The higher clearance rate during IMExt than during IMFlex (P = 0.02) demonstrates the importance of muscle deformations on lymph propulsion and experimentally confirms the current concepts of lymph formation and propulsion in voluntarily active skeletal muscle. It is suggested that lymph propulsion by working muscle is most efficient when the muscle is able to shorten close to its minimum length.

Value of joint scintigraphy in the prediction of erosiveness in early rheumatoid arthritis

The value of scintigraphy in predicting development of new erosions in small peripheral joints was studied by visual evaluation of scintigrams and by three computerised methods. In 13 patients with newly diagnosed rheumatoid arthritis a total of 387 joints were examined clinically, scintigraphically, and radiographically. The follow up period was 24 months. Four eroded joints in three patients were found at the onset. Of the joints which were to become eroded, 46/47 were scintigraphically active at all the check ups. Erosions were detected earlier in foot joints than in finger joints. New erosions were especially prone to appear in joints with persisting and high scintigraphic activity. On the contrary, inactive joints by repeated scanning never eroded. Scintigraphic and clinical activity and radiographic erosiveness correlated significantly with each other. The sensitivity and specificity of visual scintigraphic assessment and the relative pixel activity method proved to be superior to the region of interest methods and clinical evaluation for prediction of erosiveness.

Scintigraphy of rheumatoid peripheral joints. Reliability of visual assessment vs. computerized methods

99mTc-methylene diphosphonate (99mTc-MDP) scintigraphy of peripheral joints was studied by visual evaluation (Visual Assessment) of the scintigrams and by a computerized region-of-interest (ROI) method without, or with a reference region (ROI method or Corrected ROI method). Sixteen rheumatoid patients and a total of 477 peripheral joints were studied and the results compared with clinical joint activity evaluated by joint palpation. The ROI method without a reference proved to be insensitive and hence unsuitable for clinical use. The results of Visual Assessment and the Corrected ROI method correlated well with each other and with clinical joint activity. The sensitivity of the methods in detecting a clinically inflamed finger joint was: ROI 6%, Corrected ROI 71% and Visual Assessment 75%. The corresponding figures for peripheral joints of the feet were as follows: 28%, 41% and 58%. We conclude that, for clinical use, Visual Assessment of the scintigram is adequate and the method of choice.

Effects of smoking and nicotine on human prostacyclin and thromboxane production in vivo and in vitro

We studied the effects of smoking and nicotine on the production of proaggregatory thromboxane A2 (TxA2), antiaggregatory prostacyclin (epoprostenol, PGI2), and on lipid peroxidation in vivo and in vitro. In the in vivo study, serum concentrations of thromboxane B2 (TxB2), a stable metabolite of TxA2, increased immediately after smoking three cigarettes but not after smoking the equivalent amount of tobacco in a pipe, whereas serum lipid peroxide values did not change in either group. In vitro, nicotine (2 X 10(-3) mol/liter) inhibited pulmonary TxB2 production by 70% and simultaneously stimulated the production of 6-keto-prostaglandin F1 alpha, a stable metabolite of PGI2, by 40%, which suggest that nicotine does not exert its effect at the cyclooxygenase level. During aggregation in platelet-rich plasma, TxB2 production was inhibited by 53% with 2 X 10(-3) mol/liter of nicotine, and during whole blood clotting the inhibition was 34% with 2 X 10(-4) mol/liter of nicotine. Thus the rise in cigarette smokers' serum TxB2 was probably caused by some constituent of cigarette smoke other than nicotine. The increased production of TxA2 following cigarette smoking may provide one explanation for the increased incidence of atherosclerosis and its complications in cigarette smokers.

Differential inhibition of platelet thromboxane and lung prostacyclin production by sulphinpyrazone, acetylsalicylic acid and indomethacin by human tissues in vitro

To compare the inhibition of human platelet and lung cyclo-oxygenases by sulphinpyrazone (SP), acetylsalicylic acid (ASA) and indomethacin, we investigated their effects on platelet thromboxane A2 (TxA2) production during spontaneous clotting and on prostacyclin (PGI2) and TxA2 productions of superfused minced human lung. The synthesis of proaggregatory, vasoconstricting TxA2 and antiaggregatory, vasodilating PGI2 were evaluated by measuring the concentration of their stable metabolites thromboxane B2 (TxB2) and 6-keto-prostaglandin F1 alpha respectively, by radioimmunoassays. The basal platelet TxB2 production was 241.0 +/- 56.3 ng/ml (mean +/- SEM, n = 12). The concentrations needed for 50% inhibition of this production (IC50) were 41.3 mumol/l for sulphinpyrazone, 6.3 mumol/1 for ASA and 0.094 mumol/l for indomethacin. The lung generated 23.8 +/- 5.5 ng/g/min (mean +/- SEM, n = 6) of 6-keto-PGF1 alpha and 8.5 +/- 1.8 ng/g/min of TxB2. The IC50 values for pulmonary 6-keto-PGF1 alpha and TxB2 productions were 530.0 mumol/l for SP, 370.0 mumol/l for ASA and 50.0 mumol/l for indomethacin. Thus pulmonary cyclo-oxygenase, presumably originating from endothelial cells, was 13, 59, and 532 times more resistant to these prostaglandin synthesis inhibitors (PGI's) than platelet cyclo-oxygenase. These data suggest that there are considerable differences in the concentration ranges of various PGI's by which the PGI2/TxA2 balance can be shifted to a dominance of PGI2.

One milligramme of acetylsalicylic acid daily inhibits platelet thromboxane A2 production

To seek the lowest dose of acetylsalicylic acid (ASA) capable of inhibiting platelet thromboxane A2 (TxA)2 production, 18 healthy volunteers ingested 9 mg, 3 mg or 1 mg of ASA/day for twenty days and the release of TxB2 (a metabolite of TxA2) during the spontaneous clotting of blood was measured by radioimmunoassay. In addition, the production of prostacyclin (epoprostenol, PGI2) was investigated by measuring the urinary excretion of its break-down product, 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha) by radioimmunoassay. Significant inhibition of platelet TxA2 production was seen from the 15th day of treatment onwards with 1 mg of ASA (maximally 15%), from the 4th day of treatment onwards with 3 mg of ASA (maximally 40%), from the 1st day of treatment onwards with 9 mg of ASA (maximally 67%). No ASA dose changed platelet counts or urinary 6-keto-PGF1 alpha excretion. One mg of ASA daily, is the lowest dose ever shown to inhibit platelet TxA2 production.

Ethanol inhibits platelet thromboxane A2 production but has no effect on lung prostacyclin synthesis in humans

Ethanol (88-880 mmol/l) inhibited the formation of proaggregatory, vasoconstricting thromboxane A2 (TxA2) during whole blood clotting and during thrombin-induced aggregation of platelet rich plasma. This inhibition was counteracted by the addition of exogenous arachidonic acid, which suggested that ethanol suppressed the liberation of arachidonic acid, evidently by inhibiting phospholipase A2. Ethanol had no effect on the formation of prostacyclin (PGI2, epoprostenol), the endogenous antagonist of TxA2, by human lung. Thus our results suggest that ethanol may shift the balance between TxA2 and PGI2 to the dominance of antiaggregatory, vasodilating PGI2 by suppressing the release of arachidonic acid in platelets. This finding might partly explain why ethanol protects against atherosclerosis and also the increased risk of subarachnoidal haemorrhage after heavy ethanol intake.

The effect of prolonged treatment with sulphinpyrazone on thromboxane A2 and prostacyclin in man

We studied the effect of 3 weeks' treatment with 4 x 200 mg of sulphinpyrazone daily (six healthy volunteers) on proaggregatory thromboxane A2 (TxA2) and antiaggregatory prostacyclin (PGI2). Platelet TxA2 production was evaluated by measuring its stable metabolite, immunoreactive thromboxane B2, from serum, and vessel wall PGI2 production by measuring its stable metabolite, immunoreactive 6-keto-prostaglandin F1 alpha in plasma. The TxA2 production (initially 209.0 +/- 27.1 ng/ml, mean +/- s.e. mean) decreased to about 30% from the second day of the treatment onwards, and it recovered in three days after the discontinuation of the treatment. PGI2 (initially 33.6 +/- 3.6 pg/ml) did not change. The shift of the balance between TxA2 and PGI2 to the dominance of antiaggregatory PGI2 during sulphinpyrazone treatment may be involved with the efficacy of the drug in the secondary prevention of myocardial infarction.

Intervillous blood flow in normal and complicated late pregnancy measured by means of an intravenous 133Xe method

Intervillous blood flow (IVBF) was measured intravenously with a new quantitative 133Xe method in 50 normal and 74 complicated late pregnancies between the 35th and 42nd weeks. The distribution of individual flow rates seemed to be fairly wide in both the normal and the pathological groups. The mean rate of IVBF in normal pregnancies was 140 ml/100 ml of intervillous space/min. The lowest mean flow values were observed in pregnancies complicated by diabetes mellitus (class B-E), cholestasis of pregnancy and severe pre-eclampsia, a highly significant difference (p less than 0.001) from the mean IVBF observed in normal pregnancies. The significance of the results in the different groups has been discussed in detail. This method may open up a new diagnostic area in the management of high-risk pregnancies.

Haemodynamic and hormonal effects of short-term oestradiol treatment in postmenopausal women

Haemodynamic changes during a 3-wk treatment with oestradiol valerianate (2 mg/day orally) were studied in 12 postmenopausal women by isotope 113Inm radiocardiography. Systolic blood pressure measured in the supine position decreased during oestradiol treatment by 3% (P less than 0.05) and the diastolic blood pressure decreased by 4% (P less than 0.01). The heart rate decreased by 15% (P less than 0.001). Blood volume increased during oestrogen treatment by 5% (P less than 0.05) whereas cardiac output decreased by 9% (P less than 0.05). Stroke volume increased by 13% (P less than 0.001) due to concomitant decrease in heart rate. Changes in plasma oestrone and oestradiol concentrations during oestradiol valerianate substitution showed a positive correlation with the changes of blood volume.

[Uteroplacental blood flow in normal pregnancy before and after short-term treatment with (isoxsuprine) beta-sympathicomimetica (author's transl)]

The uteroplacental blood flow was measured in 26 normal pregnant women between the 36-43 weeks of pregnancy before and after a short-term treatment of isoxsuprine. The patients had no complications of pregnancy and no uterine contractions during this time. We used our intravenous Xe-133 method for measuring the intervillous and myometrial perfusion (20). During the blood flow measurements we also measured maternal arterial blood pressure and heart rate. To evaluate the short-term treatment effect of isoxsurpine we applied an intravenous injection or infusion. The placental flow was (124 +/- 32) before and (117 +/- 39) ml/min/100 ml after isoxsuprine application. The corresponding values for myometrial flow were (7,8 +/- 3,5) and (6,2 +/- 3,0) ml/min/100 g. The pathological changes of the uterplacental blood flow with vena caval syndrom will referred in text. There was a statistically significant increase in maternal heart rate and a decrease in blood pressure.

Transmission of vibration in the hand-arm system with special reference to changes in compression force and acceleration

The transmission of longitudinal vibration in the hand-arm system of five subjects was investigated. Altogether 405 individual tests were made. Vibration was measured with an accelerometer (weight 0.4 g) fixed in turn to the wrist, the elbow, and the upper arm by means of a supporting device (weight 34 g). A handle with strain gauges attached was used to study the effect of compression force (10, 20 and 40 N) and constant acceleration (1, 3 and 10 g) on the transmission of vibration at frequencies from 20 to 630 Hz. In the curves recorded, sharp dips appeared which were evidently caused by resonances from the soft tissues of the hand. However in the hand-arm system no common resonance frequency was observed that would harmfully affect the health of workers. Vibration in the hand-arm system was attenuated at an average of 3 dB per octave at the frequencies between 20 and 100 Hz. Between 100 and 630 Hz the attenuation was about 6 dB per octave in the wrist and 10 dB per octave in the elbow and upper arm. At the frequency of 630 Hz the attenuation was hence about 35 dB in the wrist and about 45 DB in the elbow. The attenuation of vibration in the elbow joint was 2 to 4 dB at all frequencies. The hand-arm system appears to be linear at the acceleration range considered; the increase in handle vibration by, e.g., 10 dB also increased vibration in the hand by 10 dB. When the grip strength was increased fourfold, i.e., 12 dB, vibration increased only 3 to 5 dB in the hand-arm system. Thus changing the weight of a vibrating tool does not reduce vibration enough. Therefore attempts to reduce vibration should concentrate on the mechanical parts of the engines.