A Proposed Phonography-Based Measurement of Fetal Breathing Movement Using Segmented Structures with Frequency Splitting

This paper proposes a detection method of fetal breathing movement (FBM) as an important data of fetal well-being. To analyze the chaotic nature of the individual episodes, the frequency band has been split into single test frequencies in order to find its starting point (SP) as a signal free (quiet) zone. Computing some features of the signal the sound will be distinguishable from the disturbing signals as hiccups, body's rotation and limb movements or even additional noises of maternal heart beats. The SPs of the episodes are characterized by an approximation process in order to select the real ones.Clinical relevance- The method is an irradiation free measurement, carried out on the maternal abdomen. Furthermore, connected with the fetal phonocardiographic (fPCG) monitoring the method offers a non-invasive way for FBM detection applicable also at home. More than 50 pregnancies were examined with the proposed method for at least for 20-min with synchronous measurements by the proposed phonographic device and a 3D ultrasound machine in the third trimester.

Low Back Pain (LBP), work and absenteeism

BACKGROUND

Occupational physical demands are commonly assumed the cause of work-related Low Back Pain (LBP) and absenteeism.

OBJECTIVES

To analyse relationships between LBP at work, physical demands and absenteeism.

METHODS

Workers filled out a questionnaire on socio-demographic and work-related factors, general health, LBP (number of episodes in a 12-month period, pain severity and intensity), and occupational hazards related with physical demands.

RESULTS

735 workers completed the questionnaire (male n = 359). A high proportion of workers n = 507 (69%), from different occupational backgrounds, reported at least one LBP episode in the previous 12-month period. The highest ratio of subjects with more than 6 episodes of LBP per year was found among public services employees (31.8%) and the lowest ratio among administrative workers (10.3%). The highest ratio of workers (39%) were classified as sedentary workers, 34% of workers having a low or moderate level of physical demands in their work, and 27% reported high levels of physical demands in their work. There was a 4 % absenteeism rate in a 12-month period, which was significantly higher in the group with physically demanding work. Those subjects with higher physical requirements at work have increased odds of having more than 3 episodes of LBP during the previous year (p < 0.05) in comparison with subjects with more sedentary jobs and those with low or moderate physical demands. High intensity work, compared to sedentary work, is associated with an increased probability of being absent of work because of LBP in a previous 12-month period (OR = 3.12; CI 1.23-7.89; p = 0.016).

CONCLUSIONS

Our findings suggest there is an association between highly physically demanding jobs, LBP and absenteeism. These results may contribute to the improvement of LBP assessment and prevention programs in Occupational Health Services.

Endogenous thrombin potential and examination of a further 31 analytes in liver transplant candidates

BACKGROUND

To predict the change in patient status and differentation of the basic diseases, endogenous thrombin potential (ETP), clinical chemistry, and coagulation variables were measured in liver transplant-listed patients with different etiologies.

METHODS

Differences in values of ETP and analytes of 30 control persons and 164 cirrhotic patients were examined by means of binary logistic regression. The relationship between the analytes and ETP parameters were analyzed by means of Spearman correlation. The different etiologies of cirrhosises were studied by factor and discriminant analyses. Binary logistic regression was applied to forecast changes in clinical status. Survival analysis was carried out with the appropriate variable.

RESULTS

International Normalized Ratio and activated partial thromboplastin time values were higher, whereas the area-under-the-curve values were lower in cirrhosis than in healthy subjects. A strong relationship was found only between the peak height and the anti-thrombin III (ATIII) values. In the factor analysis, 3 factors were found, which explained 81.6% of the total variance. Combination of aspartate aminotransferase and ATIII mostly separated the basic disease groups from each other in the discriminant analysis. From 35 variables, the lactate dehydrogenase (LDH) and ATIII have been suited for predicting the change in patient status. Eighty percent of patients with low ATIII and high LDH levels had deterioration of their clinical status.

CONCLUSIONS

Our study demonstrated that the ETP parameters did not provide additional information compared with "conventional" coagulation tests in cirrhosis. On the basis of our study, LDH and ATIII appear to be promising analytes to assess the clinical status of patients with cirrhosis. In our opinion, the classification system of liver transplant-listed patients can be improved with their use.

Small difference in international normalized ratio may yield a significant impact on prioritizing patients listed for liver transplantation

Priority for liver transplantation is currently based on the Model for End-stage Liver Disease (MELD) score. The aim of our study was to assess in detail the contribution of international normalized ratio (INR) differences for MELD scores because of interlaboratory variability. The samples from 92 cirrhotic patients were measured on different systems combining three coagulometers and three thromboplastin products to determine variations in INR and MELD score. The INR differences among the first four systems varied between 0 and 0.2, resulting in MELD differences of 0 to 2. The MELD scores of 92 patients changed only among 10 possible integers so that normally 2 to 10 patients shared the same MELD value. In some cases, one MELD score difference resulted in a 10 superpositioning on the waiting list. Including one more system (mechanical vs optical) into our investigations achieved a five MELD difference. Supposing an extreme situation where one patient competes with his or her lowest, all the other with their highest possible score (and visa versa), the difference may be even 20 positions, overturning the complete waiting list. In conclusion substantial interlaboratory differences in MELD score have profound clinical consequences.

Experiences with fetal phonocardiographic telemonitoring and future possibilities

Phonocardiography (PCG) makes possible the examination of some fetal cardiac anomalies which otherwise usually remain undetected during pregnancy. The application of PCG in a telemonitoring system enhances its diagnostic capabilities, allowing long-term measurements even at home. The paper summarizes the intensive fetal monitoring campaign carried out in Hungary during the last three years that yielded useful experience regarding recent and future possibilities of fetal monitoring. Results collected from a large number of measurements suggest that PCG home monitoring may be a suitable screening method for fetal congenital heart diseases, even if surgical intervention in this phase of pregnancy is not easy.

Long-term Phonocardiographic Fetal Home Monitoring for Telemedicine Systems

A novel compact method for fetal home monitoring optimized for long data acquisition time and low communication costs is presented. The method incorporates the preprocessing of disturbed acoustic signal received on the maternal abdomen. The basic idea of the preprocessing is that the detection of the systolic and diastolic sounds takes place on two separated frequency bands with autocorrelation on predicted time intervals. Measurements on 47 selected pregnant women have shown that the use of this method significantly reduces the amount of data to be transferred to the computer centre in the hospital, where only the very disturbed time periods have to be evaluated. Based on this method a new, phonocardiographic fetal telemedicine system can be built without time limitation of measurements.

Distribution and elimination of fumonisin analogues in weaned piglets after oral administration of Fusarium verticillioides fungal culture

The distribution and elimination of fumonisins after oral administration of 50 mg FB(1), 20 mg FB(2) and 5 mg FB(3) per animal day(-1) for 22 days was studied in weaned barrows. At the end of the trial, the lung, heart, liver, kidney, spleen, brain, serum, bile, muscle, fat, urine and faeces samples were collected and their content of fumonisins (FB(1), FB(2)) determined by LC-MS. The highest FB(1) concentrations were found in the liver (99.4 +/- 37.5 ng g(-1)) and kidneys (30.6 +/- 10.1 ng g(-1)), whilst the highest average amount of FB(2) was in the liver (1.4 +/- 2.3 ng g(-1)) and fat (2.6 ng g(-1) +/- 4.8) samples. Comparing the FB(1)/FB(2) ratio in different organs (19/1), it was found that the ratio in the abdominal and subcutaneous fat samples (4/1) was markedly different from those in all other tissues, namely the relative proportion of FB(2) was higher in latter cases. Of the total quantity of FB(1), the 13% taken up during 5 days was excreted unchanged with the faeces and urine. On average, in the urine and faeces, FB(1) was detected in nine- and 14-fold quantities, as compared with FB(2).

Imaging membrane protein helical wheels

Resonance patterns have been observed in 2D solid-state NMR spectra of the transmembrane segment of M2 protein from Influenza A virus in oriented samples reflecting the helical wheel of this alpha-helix. The center of this pattern uniquely defines the helical tilt with respect to the bilayer normal without a need for resonance assignments. The distribution of resonances from amino acid specific labels around the "PISA wheel" defines the rotational orientation of the helix and yields preliminary site-specific assignments. With assignments high-resolution structural detail, such as differences in tilt and rotational orientation along the helical axis leading to an assessment of helical coiling, can be obtained.

Correlations of structure, dynamics and function in the gramicidin channel by solid-state NMR spectroscopy

The high resolution structure of the gramicidin A channel has been determined in a lamellar phase environment using solid-state NMR spectroscopy. While the fold is similar to previous characterizations, channel function is exquisitely dependent on structural detail. There is essentially no structural change upon cation binding and no significant change in dynamics. The cations appear to be adequately solvated in their binding site by no more than two carbonyls and no fewer than three water molecules at any one time. The relatively large number of water molecules allows for geometric flexibility and little selectivity among monovalent cations. However, the dehydration energies of cations clearly explain the selectivity for monovalent versus divalent cations. Moreover, the binding site is shown to be delocalized, resulting in a shallow potential energy well so that efficient cation conductance can be realized. The potential energy barrier at the bilayer centre has been shown to be rate limiting under certain circumstances through a correlation between conductance and the electrostatic interactions between cations at the gramicidin monomer-monomer junction and the indole dipole moments at the lipid-water interface. The dynamics are functionally important. The time-scale for carbonyl fluctuations about the C alpha-C alpha axis and kinetic rates for cation movement in the channel are the same, suggesting a correlation between molecular dynamics and kinetics. These functional correlations will be described in light of the recent K+ channel structure and the biological challenge to achieve both selectivity and efficiency.

Validation of the single-stranded channel conformation of gramicidin A by solid-state NMR

The monovalent cation selective channel formed by a dimer of the polypeptide gramicidin A has a single-stranded, right-handed helical motif with 6.5 residues per turn forming a 4-A diameter pore. The structure has been refined to high resolution against 120 orientational constraints obtained from samples in a liquid-crystalline phase lipid bilayer. These structural constraints from solid-state NMR reflect the orientation of spin interaction tensors with respect to a unique molecular axis. Because these tensors are fixed in the molecular frame and because the samples are uniformly aligned with respect to the magnetic field of the NMR spectrometer, each constraint restricts the orientation of internuclear vectors with respect to the laboratory frame of reference. The structural motif of this channel has been validated, and the high-resolution structure has led to precise models for cation binding, cation selectivity, and cation conductance efficiency. The structure is consistent with the electrophysiological data and numerous biophysical studies. Contrary to a recent claim [Burkhart, B. M., Li, N., Langs, D. A., Pangborn, W. A. & Duax, W. L. (1998) Proc. Natl. Acad. Sci. USA 95, 12950-12955], the solid-state NMR constraints for gramicidin A in a lipid bilayer are not consistent with an x-ray crystallographic structure for gramicidin having a double-stranded, right-handed helix with 7.2 residues per turn.

Conformational trapping in a membrane environment: a regulatory mechanism for protein activity?

Functional regulation of proteins is central to living organisms. Here it is shown that a nonfunctional conformational state of a polypeptide can be kinetically trapped in a lipid bilayer environment. This state is a metastable structure that is stable for weeks just above the phase transition temperature of the lipid. When the samples are incubated for several days at 68 degrees C, 50% of the trapped conformation converts to the minimum-energy functional state. This result suggests the possibility that another mechanism for functional regulation of protein activity may be available for membrane proteins: that cells may insert proteins into membranes in inactive states pending the biological demand for protein function.