Correlation of ultrasonic measured ribeye area and fat thickness to the certain traits measured on slaughtered bulls (Short Communication)

Abstract. The aim of this study was to test accuracy of measurements done by Falco 100 (Pie Medical) ultrasonic equipment. 10 Angus, 10 Hungarian Simmental, 10 Limousin and 10 Charolais fattening bulls were measured at the feedlot just before slaughtering. Fat thickness at the rump (P8) and ribeye area (REA) were realized from each animal. After slaughtering, the data of slaughter and carcass weights were collected and carcasses were judged on the base of EUROP system. The database was examined by SPSS 9.0 for Windows. Average liveweight of Angus was 645 ± 41.5 kg, of Hungarian Simmental was 676 ± 41.8 kg, of Limousin was 655 ± 50.8 kg and of Charolais was 694 ± 42.3 kg at the measurement. REA measured with ultrasound was 102.9 ± 8.9 cm2, 102.7 ± 10.4 cm2, 111.2 ± 9.6 cm2 and 106.4 ± 9.5 cm2, respectively. P8 was 1.05 ± 0.28 cm, 0.62 ± 0.13 cm, 0.62 ± 0.09 and 0.61 ± 0.18 cm, respectively. Correlation between ultrasonic and carcass REA in case of mentioned breeds was 0.74, 0.74, 0.94 and 0.80. Correlation between P8 and EUROP fat score was 0.51, 0.73, 0.56 and 0.28, respectively. Overall correlation between ultrasonic and carcass REA was 0.83 (P≤0.01), and between P8 and EUROP fat score was 0.69 (P≤0.01).

Context-independent, temperature-dependent helical propensities for amino acid residues

Assigned from data sets measured in water at 2, 25, and 60 degrees C containing (13)C=O NMR chemical shifts and [theta](222) ellipticities, helical propensities are reported for the 20 genetically coded amino acids, as well as for norvaline and norleucine. These have been introduced by chemical synthesis at central sites within length-optimized, spaced, solubilized Ala(19) hosts. The resulting polyalanine-derived, quantitative propensity sets express for each residue its temperature-dependent but context-independent tendency to forego a coil state and join a preexisting helical conformation. At 2 degrees C their rank ordering is: P << G < H < C, T, N < S < Y, F, W < V, D < K < Q < I < R, M < L < E < A; at 60 degrees C the rank becomes: H, P < G < C < R, K < T, Y, F < N, V < S < Q < W, D < I, M < E < A < L. The DeltaDeltaG values, kcal/mol, relative to alanine, for the cluster T, N, S, Y, F, W, V, D, Q, imply that at 2 degrees C all are strong breakers: DeltaDeltaG(mean) = +0.63 +/- 0.11, but at 60 degrees C their breaking tendencies are dramatically attenuated and converge toward the mean: DeltaDeltaG(mean) = +0.25 +/- 0.07. Accurate modeling of helix-rich proteins found in thermophiles, mesophiles, and organisms that flourish near 0 degrees C thus requires appropriately matched propensity sets. Comparisons are offered between the temperature-dependent propensity assignments of this study and those previously assigned by the Scheraga group; the special problems that attend propensity assignments for charged residues are illustrated by lysine guest data; and comparisons of errors in helicity assignments from shifts and ellipticity data show that the former provide superior precision and accuracy.

Pharmacological manipulation of L-carnitine transport into L6 cells with stable overexpression of human OCTN2

The high-affinity Na+-dependent carnitine transporter OCTN2 (SLC22A5) has a high renal expression and reabsorbs most filtered carnitine. To gain more insight into substrate specificity of OCTN2, we overexpressed hOCTN2 in L6 cells and characterized the structural requirements of substances acting as human OCTN2 (hOCTN2) inhibitors. A 1905-bp fragment containing the hOCTN2 complete coding sequence was introduced into the pWpiresGFP vector, and L6 cells were stably transduced using a lentiviral system. The transduced L6 cells revealed increased expression of hOCTN2 on the mRNA, protein and functional levels. Structural requirements for hOCTN2 inhibition were predicted in silico and investigated in vitro. Essential structural requirements for OCTN2 inhibition include a constantly positively charged nitrogen atom and a carboxyl, nitrile or ester group connected by a 2-4-atom linker. Our cell system is suitable for studying in vitro interactions with OCTN2, which can subsequently be investigated in vivo.

Fetal breathing transmission in phonocardiographic monitoring telemedicine systems

The phonocardiographic monitoring of fetal heart activity due to its passive nature enables extremely long measuring times providing thus the possibility of fetal breathing recovery. The long monitoring time is required because of the temporary appearing of breathing movement. However, the long measurement time and consequently the large amount of data to be transmitted to the hospital's computer centre may be costly on mobile phone network. To keep monitoring costs low an appropriate data compression should be applied assuring the transmission of all important features of the detected acoustic signal. The present work summarizes the results of the extension of the novel telemedicine system with measurement of breathing periodicity and the achieved compression level of acquisited data. The Golomb-Rice compression is applied for lossless transmission of the segmented beat cycles considering the importance of the given segments in order to obtain the most accurate transfer of beat-to-beat time and all irregular heart sounds.

Toxicity of statins on rat skeletal muscle mitochondria

We investigated mitochondrial toxicity of four lipophilic stains (cerivastatin, fluvastatin, atorvastatin, simvastatin) and one hydrophilic statin (pravastatin). In L6 cells (rat skeletal muscle cell line), the four lipophilic statins (100 micromol/l) induced death in 27-49% of the cells. Pravastatin was not toxic up to 1 mmol/l. Cerivastatin, fluvastatin and atorvastatin (100 micromol/l) decreased the mitochondrial membrane potential by 49-65%, whereas simvastatin and pravastatin were less toxic. In isolated rat skeletal muscle mitochondria, all statins, except pravastatin, decreased glutamate-driven state 3 respiration and respiratory control ratio. Beta-oxidation was decreased by 88-96% in the presence of 100 micromol/l of the lipophilic statins, but only at higher concentrations by pravastatin. Mitochondrial swelling, cytochrome c release and DNA fragmentation was induced in L6 cells by the four lipophilic statins, but not by pravastatin. Lipophilic statins impair the function of skeletal muscle mitochondria, whereas the hydrophilic pravastatin is significantly less toxic.

Organofluorine Inhibitors of Amyloid Fibrillogenesis†

The design and application of an effective, new class of organofluorine inhibitors of amyloid fibrillogenesis are described. Based on experimental evidence a core structure containing indol-3-yl, trifluoromethyl, hydroxyl, and carboxylic acid ester functions has been designed. Several substituted derivatives of this core structure have been synthesized, using various indole derivatives. While all inhibitor candidates have shown considerable effect (20-70% inhibition) in structure-activity relationship studies (inhibitor/Abeta = 10 ratio), several compounds have demonstrated excellent activity (93-96% inhibition). Using concentration dependence studies, the activity of the most active molecules have been quantified. These inhibitors practically completely block the fibril formation of Abeta(1)(-)(40), as shown by maximum inhibition values (IC(max) = 98-100%). The median inhibitor concentration values (IC(50) = 0.23-0.53 mol(inhibitor)/mol(A)(beta)) demonstrate favorable stoichiometry for the inhibition. The respective elimination of the functional groups from the core structure has resulted in a partial or complete loss of activity, indicating the significant role of each group. Experiments with these derivatives suggest the particular importance of the acidic hydroxyl group during peptide-inhibitor interaction.

Sonochemical asymmetric hydrogenation of isophorone on proline modified Pd/Al2O3catalysts

The sonochemical asymmetric hydrogenation of isophorone (3,3,5-trimethyl-2-cyclohexenone) by proline-modified Pd/Al2O3 catalysts is described; presonication of a commercial Pd/Al2O3-proline catalytic system resulted in highly enhanced enantioselectivities (up to 85% ee).

Structural and dynamic features of Alzheimer's Abeta peptide in amyloid fibrils studied by site-directed spin labeling

Electron paramagnetic resonance spectroscopy analysis of 19 spin-labeled derivatives of the Alzheimer's amyloid beta (Abeta) peptide was used to reveal structural features of amyloid fibril formation. In the fibril, extensive regions of the peptide show an in-register, parallel arrangement. Based on the parallel arrangement and side chain mobility analysis we find the amyloid structure to be mostly ordered and specific, but we also identify more dynamic regions (N and C termini) and likely turn or bend regions (around residues 23-26). Despite their different aggregation properties and roles in disease, the two peptides, Abeta40 and Abeta42, homogeneously co-mix in amyloid fibrils suggesting that they possess the same structural architecture.

The prevalence of multiple sclerosis, distribution of clinical forms of the disease and functional status of patients in Csongrád County, Hungary

OBJECTIVE

The aim of this study was to determine the prevalence of multiple sclerosis (MS) in the population of Csongrád County, Hungary (400,128 inhabitants) and to determine the functional status (based on the Expanded Disability Status Scale; EDSS) of the patients according to the clinical forms of the disease.

METHODS

The diagnosis was established with the aid of the Poser diagnostic criteria, and the degree of physical disability was determined using the Kurtzke EDSS.

RESULTS

In Csongrád County, the prevalence of MS is 62/100,000. The distribution of patients according to the clinical forms of MS was as follows: 15% had the benign form, 54% had relapsing-remitting MS, 20% had secondary chronic progressive MS and 11% had the primary chronic progressive form of MS. Sixty percent of relapsing-remitting MS patients had an EDSS score of 0-4 points and 33% had an EDSS score of 4.5-6.5 points.

CONCLUSION

The distribution of patients according to the clinical forms of the disease in this representative population is comparable to results in other regions of the world.

[Analgesics-induced chronic renal failure in patients on dialysis therapy in Hungary]

In recent years elaboration of the diagnosis of analgesic-nephropathy (ANP) with the help of imaging techniques significantly increased the possibility of diagnosing the disease. Therefore, evaluating the prevalence of ANP has become more accurate in our country as well. The prevalence of ANP has been investigated in patients who have newly been taken into the dialysis program due to renal disease of unknown aetiology in 22 dialysis centers between December 1994-December 1997. The diagnosis of ANP has been based on revealing chronic drug abuse in the history and positive results of renal imaging (decrease in length of both kidneys combined with either bumpy contours and/or papillary calcification). Among 284 patients dialysed with unknown diagnosis 42 (14.8% of all cases) proved to have ANP. All patients except 2 took analgesic mixtures containing phenacetin/paracetamol, phenason derivatives, acetilsalysilic acid, caffeine and/or codeine. According to their investigations, ANP is a common disease resulting in end-stage renal failure in Hungary as well.

Asymmetric sonochemical reactions enantioselective hydrogenation of alpha-ketoesters over platinum catalysts

The sonochemical enantioselective hydrogenation of different alpha-ketoesters to the corresponding hydroxy derivatives over cinchona modified Pt catalysts is described. Ultrasonic irradiation was found to be beneficial in improving the optical yields. Besides studying the reaction rates and enantioselectivities, the effect of ultrasonics on the catalyst-modifier system and the scale-up of the process will also be considered.

A rule-based phonocardiographic method for long-term fetal heart rate monitoring

A real-time method for fetal heart rate (FHR) monitoring based on signal processing of the fetal heart sounds is presented. The acoustic method, which utilizes an adaptive time pattern analysis to select and analyze those heartbeats that can be recorded without artefact, is guided by a number of rules involving an introduced confidence factor on the timing prediction. The algorithm was implemented in a low-power portable electronic instrument to enable long-term fetal surveillance. A large number of clinical tests have shown the very good performance of the phonocardiographic method in comparison with FHR curves simultaneously recorded with ultrasound cardiotocography. Indeed, approximately 90% of the time, the acoustic FHR curve remained inside a +/- 3 beats/min tolerance limit of the reference ultrasound method. The confidence was typically CF > 0.85. The acoustic method exceeded a +/- 5 beats/min limit relative to the ultrasound method approximately 5% of the time. Finally, no relevant FHR data was measured approximately 5% of the time.

Modulation of multidrug resistance protein expression in porcine brain capillary endothelial cells in vitro

Multidrug resistance-associated protein (MRP) is a transport system that is involved in the elimination of xenobiotics and biologically active endogenous substrates. Recently, the presence of MRP has been demonstrated in cultured brain capillary endothelial cells (BCECs). The time-dependent, functional expression of MRP in porcine BCECs was investigated to assess the value of this cell culture model for drug transport at the blood-brain barrier. Western blot analysis was used to investigate MRP expression in freshly isolated porcine BCECs and compared to MRP expression at days 8 and 10 in culture. Subcellular localization of MRP was investigated by immunocytochemistry with an MRP-specific monoclonal antibody, MRPr1. Functional activity of MRP was assessed by efflux studies with the fluorescent MRP substrate glutathione-methylfluorescein (GS-MF). No significant MRP expression was detected in freshly isolated endothelial cells. However, MRP expression is up-regulated in cell culture in a time-dependent manner. Immunostaining revealed predominantly perinuclear and, to a lesser degree, plasma membrane localization of MRP. At 10 degrees C GS-MF efflux was significantly decreased, indicating the involvement of an energy-dependent transport system. Efflux of GS-MF was apparently inhibited by MK571, a specific inhibitor for MRP. Porcine BCECs demonstrate up-regulation of functional MRP expression during culture, as observed in human tissue, and therefore might serve as a useful in vitro system for studying MRP-mediated blood-brain barrier transport.

Differential regulation of somatostatin receptor type 2 (sst 2) expression in AR4-2J tumor cells implanted into mice during octreotide treatment

Octreotide is a somatostatin analogue that is widely used for cancer therapy and tumor imaging. Its efficacy in tumors depends mainly on the expression of the somatostatin receptor type 2 (sst 2). Desensitization and down-regulation of sst 2 after agonist exposure can have important consequences for patients under ongoing octreotide therapy because it may induce temporary tumor unresponsiveness and impair sst 2-based tumor scintigraphy. Therefore, we have investigated the effect of octreotide on sst 2 expression in vitro, as well as in a tumor mouse model. In vitro, short exposure to octreotide induced rapid dose-dependent down-regulation of sst 2 in the rat pancreatic AR4-2J cell line. Within 0.5 h, 80% of sst 2 had disappeared from the cell surface. A total recovery required 24 h and was shown to depend on protein synthesis, but not on new sst 2 mRNA transcription, indicating that sst 2 was probably degraded during the down-regulation process. Similar results were obtained in vivo. On the other hand, long-term continuous release of octreotide for 7 days, as achieved with octreotide-containing osmotic minipumps, caused sst 2 up-regulation in vivo, but not in vitro. Furthermore, this up-regulation of sst 2 in tumor-bearing scid mice was shown to depend on constant exposure of the animals to octreotide, as it was not observed when octreotide was given discontinuously in two s.c. daily injections. These results demonstrate that the continuous release of a small amount of octreotide, which in cancer therapy may be achieved with long-acting release formulations of the peptide, can induce sst 2 up-regulation on cancer cells. This may improve the efficacy of both tumor imaging and long-term octreotide therapy.

HIV protease inhibitor ritonavir: a more potent inhibitor of P-glycoprotein than the cyclosporine analog SDZ PSC 833

The effect of P-glycoprotein inhibition on the uptake of the HIV type 1 protease inhibitor saquinavir into brain capillary endothelial cells was studied using porcine primary brain capillary endothelial cell monolayers as an in vitro test system. As confirmed by polymerase chain reaction and Western blot analysis, this system functionally expressed class I P-glycoprotein (pgp1A). P-Glycoprotein isoforms pgp1B or pgp1D could not be detected. The uptake of saquinavir into endothelial cells could be described as the result of a diffusional term of uptake and an oppositely directed saturable extrusion process. Net uptake of saquinavir into cultured brain endothelial cells could be increased significantly up to 2-fold by SDZ PSC 833 in a dose-dependent manner, with an IC(50) of 1.13 microM. In addition, the HIV protease inhibitor ritonavir inhibited p-glycoprotein-mediated extrusion of saquinavir with an IC(50) of 0.2 microM, indicating a high affinity of ritonavir for p-glycoprotein. In conclusion, we showed that the HIV protease inhibitor ritonavir is a more potent inhibitor of P-glycoprotein than the multidrug resistance (MDR)-reversing agent SDZ PSC 833. The inclusion of this drug in combination regimens may greatly facilitate brain uptake of HIV protease inhibitors, which is especially important in patients suffering from AIDS dementia complex.

[Treatment of relapsing-remitting multiple sclerosis with interferon beta type 1-b]

Interferon-beta-1b was the first drug found to slow the progression of relapsing-remitting multiple sclerosis, with a reported decrease in the relapse rate of up to 34%. The present study involved 35 patients treated with interferon-beta-1b for one year. The aims of the study were: a) to compare the changes in the relapse rate and the number of days of hospitalization with other data, b) to compare the steroid needs required to treat relapses for one year before and in the year of interferon-beta-1b treatment. Our data indicated that the relapse rate may decrease as much as 77% following the introduction of interferon-beta-1b treatment. The adverse effects and the changes in the EDSS grades were similar to the published data. The duration of hospitalization decreased by 84% and the amount of methylprednisolone needed for remission by 78%. This data suggest that the impairment of the condition of the patients may be delayed considerably, while some of them can continue to work for a longer period, the standard of life of these patients therefore being more tolerable.

Sister of P-glycoprotein expression in different tissues

Sister of P-glycoprotein (spgp) is a gene that is closely related to the P-glycoprotein family (Pgps). This class of proteins belongs to the superfamily of ATP-binding cassette transporters and is known for its involvement in pharmacological drug interactions. Therefore, this study investigated the distribution of spgp expression in different tissues known for their high levels of Pgps expression such as brain, liver, kidney, small- and large-gut mucosa. Analysis was done by using the reverse transcription-polymerase chain reaction. In addition to a high expression in the liver, we were able to demonstrate a significant spgp expression in brain grey cortex, small- and large-gut mucosa. Although Pgps are expressed in the kidney and brain capillary endothelial cells, no expression of spgp was detected in these tissues, which might indicate that spgp has no function in the blood-brain barrier and is not involved in the renal excretion of drugs.

Evidence for different ABC-transporters in Caco-2 cells modulating drug uptake

PURPOSE

Secretory systems contribute to drug absorption in the gastrointestinal tract. The purpose of this study was the identification of members of the ATP binding cassette superfamily of secretory transport proteins that may potentially modulate drug absorption in Caco-2 cells, which are an important cellular model predicting enteral absorption of drugs.

METHODS

Kinetic studies as well as PCR- and Western blot studies with confluent epithelial layers of human Caco-2 cells.

RESULTS

The study demonstrates functional expression of multidrug resistance related protein (MRP) and P-glycoprotein (P-gp) in Caco-2 cells: 1) Efflux studies with the MRP specific substrate glutathion-methylfluorescein (GS-MF) showed functional activity of MRP in Caco-2 cells preloaded with the metabolic precursor of GS-MF, chloromethylfluoresceine-diacetate, CMFDA. Excretion of GS-MF was decreased in presence of the MRP-blocker M K-571.2) Transport experiments with cyclosporin A demonstrated the functional activity of P-gp. Cellular accumulation was increased in presence of the P-gp blocking agent SDZ-PSC 833. 3) The expression of the 190 kDa protein MRP and the 170 kDa protein P-gp in Caco-2 cells was shown by Western blot analysis with specific monoclonal antibodies. 4) The expression of MRP-mRNA in Caco-2 cells was detected by RT-PCR and compared with the MRP over-expressing cell line H69AR. MRP primers recognize specifically human MRP1 (GenBank accession number L05628), but not all other published sequences of MRP (MRP2-MRP6). P-gp expression on mRNA-level was also confirmed by RT-PCR.

CONCLUSIONS

The data demonstrate that besides P-gp, multidrug resistance related protein (MRP) is functionally expressed in Caco-2 cells and contributes to the active excretion of substrates in this cell line.

Transport of the beta-lactam antibiotic benzylpenicillin and the dipeptide glycylsarcosine by brain capillary endothelial cells in vitro

Peripherally administered beta-lactam antibiotics, which are structural analogs of tripeptides, may cause neurotoxic reactions or induce seizures. Previous in vivo studies provided evidence for brain uptake of these antibiotics. In the present work, we studied the extent and mechanism of the uptake of benzylpenicillin and glycylsarcosine by brain microvessel endothelial cells in vitro, using freshly isolated and cultured porcine brain capillary endothelial cells. Characterization of the cell culture model demonstrated the functional expression of the system transporting the neutral amino acids leucine and phenylalanine. The initial rate of uptake of benzylpenicillin was >3-fold greater than the rate of uptake of the extracellular marker sucrose (ratio, 3.29 +/- 0.37), whereas uptake of glycylsarcosine did not differ from that of sucrose. The differences in cellular uptake correlated with the octanol/buffer partition coefficients for glycylsarcosine and benzylpenicillin (1.16 x 10(-3) for glycylsarcosine and 6.83 x 10(-2) for benzylpenicillin). The concentration-dependent uptake of benzylpenicillin (1-2000 microM) was not saturable and was not sensitive to shifts in pH or temperature. The permeability-surface area product for the uptake of benzylpenicillin at pH 7.4 was determined from these experiments and was found to be 8.1 x 10(-5) ml/sec/g of brain. This value was very close to the value determined in in vivo studies. Uptake of benzylpenicillin and glycylsarcosine was not reduced in the presence of 1 mM ceftibuten or 100 microM probenecid. The findings with cultured cell monolayers were confirmed using freshly isolated endothelial cells. These in vitro data are compatible with benzylpenicillin, but not glycylsarcosine, being able to penetrate endothelial cells. Uptake of benzylpenicillin by brain capillary endothelial cells occurs by a slow nonsaturable process, with no evidence for carrier-mediated transport.

An improvement of the acoustic fetal heart rate monitoring using statistical evaluation of the abdominal signal

An improved acoustical method for fetal heart rate (FHR) measurement is presented. The beat identification is based on the selection of the power peaks measured on two frequency channels. The identification of the valid peaks will be accomplished by rules, considering the timing and the amplitudes of the detected peaks with preferred search for pairs of the first and second sound. The introduced certainty factor as a function of the statistical probabilities that are related to the expected peaks, provides the reliability of the determined repetition time. Under a given certainty the result will be ignored and the FHR curve will be extended or left blank. The simplifications in the algorithms of the process reduce the required power consumption that enables its implementation in a low-power microcircuit and in this way to produce a battery-operated portable CTG instrument for long-term FHR monitoring on a passive.

Capsaicin-sensitive local sensory innervation is involved in pacing-induced preconditioning in rat hearts: role of nitric oxide and CGRP?

Among several mediators, nitric oxide (NO) and calcitonin gene-related peptide (CGRP) were suggested to be involved in the mechanism of preconditioning. We examined the possible role of the cardiac capsaicin-sensitive sensory innervation in pacing-induced preconditioning, as well as in the cardiac NO and CGRP content. Wistar rats were treated subcutaneously with capsaicin or its solvent in the sequence of 10, 30, and 50 mg/kg increasing single daily doses for 3 days to deplete neurotransmitters of the sensory innervation. Isolated hearts from both groups were then subjected to either preconditioning induced by three consecutive periods of pacing at 600 beats per minute for 5 min with 5 min interpacing periods, or time-matched non-preconditioning perfusion, followed by a 10-min coronary occlusion. NO content of left ventricular tissue samples was assayed by electron-spin resonance, and CGRP release was determined by radioimmunoassay. CGRP immunohistochemistry was also performed. In the non-preconditioned, solvent-treated group, coronary occlusion decreased cardiac output (CO) from 68.1 to 32.1 mL/min, increased left ventricular end-diastolic pressure (LVEDP) from 0.58 to 1.90 kPa, and resulted in 200 mU/min/g LDH release. Preconditioning significantly increased ischaemic CO to 42.9 mL/min (P < 0.05), decreased ischaemic LVEDP to 1.26 kPa (P < 0.05) and decreased LDH release to 47 mU/min/g (P < 0.05) in the solvent-treated group. Preconditioning did not confer protection in the capsaicin-pretreated group (ischaemic CO: 35.6 mL/min; LVEDP: 1.76 kPa; LDH 156 mU/min/g). Capsaicin-treatment markedly decreased cardiac NO content, CGRP release, and CGRP-immunoreactivity.

CONCLUSIONS

(i) The presence of an intact local sensory innervation is a prerequisite to elicit pacing-induced preconditioning in the rat heart. (ii) A significant portion of cardiac basal NO content may be of neural origin. (iii) Release of NO and CGRP from capsaicin-sensitive nerves may be involved in the mechanism of pacing-induced preconditioning.

Transport of clonidine across cultured brain microvessel endothelial cells

Brain penetration of clonidine, an alpha-2 adrenoceptor agonist, was studied using an in vitro cell culture system consisting of primary cultures of porcine brain capillary endothelial cells. Uptake of clonidine was measured as a function of its concentration in the incubation mixture. Saturation of uptake was apparent and could be described by Michaelis-Menten-type kinetics (K(M) = 1.34 mM; Vmax = 0.099 nmol/min/cm2). Saturation was not observed at a low temperature (4 degrees C). Transendothelial transport experiments revealed that translocation of clonidine cannot be attributed solely to paracellular leakage. Uptake was reduced at low extracellular pH or by using an incubation buffer that contained the K+ ionophore valinomycin. Time-dependent uptake of clonidine and transendothelial transport were slower than expected considering the high octanol-to-buffer partition coefficient of this compound. On the basis of transendothelial transport experiments, we concluded that the carrier system responsible for active transport of clonidine is located at both the apical and the basolateral membrane domain.

Dynamic aspects of the incorporation of proteins into biological membranes

The contributions of intramembranous and extramembranous segments of transmembrane proteins to frictional forces have been studied by covalently attached 14N- and 15N-indane dione and maleimide spin labels using saturation transfer electron spin resonance spectroscopy. The role of molecular size and membrane viscosity is discussed in determining rotational mobilities of proteins. By comparing the measured rotational correlation times with the predictions of hydrodynamic models the aggregation states of transmembrane proteins is estimated. On increasing the viscosity of the aqueous phase by polyols the viscous drag of the extramembranous segments of proteins is increased and from systematic hydrodynamic measurements the size of the protruding segments can be estimated. The role of slowed molecular diffusion is briefly discussed in the inhibition of enzymatic activity.

Rotational mobility of Ca2+-ATPase of sarcoplasmic reticulum in viscous media

The rotational diffusion of Ca2(+)-ATPase [Ca2+,Mg2(+)-activated ATP phosphohydrolase E.C. 3.6.1.38] was studied in native sarcoplasmic reticulum membrane by saturation transfer ESR spectroscopy after covalent labelling of intramembranous sulfhydryl groups with nitroxyl derivative of maleimide (5-MSL) as a function of sucrose and glycerol in the suspending medium. The relative enzymatic activity of sarcoplasmic reticulum was followed by increasing the viscosity of the aqueous phase. The ATP hydrolysing activity of the enzyme decreased differently on adding sucrose and glycerol. In the case of sucrose the reciprocal of power dependence of viscosity was observed, whereas for glycerol an exponential decay law was obtained, indicating solvent-protein interaction. On increasing the viscosity of the aqueous phase by either sucrose or glycerol, no changes were observed in the intramembranous viscosity as measured using intercalated spin-labelled stearic acid (16-SASL). The effective rotational correlation time of the protein was measured, as a mobility parameter, using saturation transfer ESR spectroscopy and found to be increased linearly with the viscosity of the sucrose containing medium and for the extramembranous size a height of 6.8 nm was obtained, indicating that approx. 82% of the volume of Ca2(+)-ATPase protein is external to the sarcoplasmic reticulum. The addition of glycerol probably promoted protein-protein interaction, as indicated by the larger changes in rotational diffusion and non-linear viscosity dependence.

An instrument using parallel filtering of acoustic signals to record fetal heart rate

A novel portable instrument for long-term recording of fetal heart rate has been developed, based on the detection and evaluation of maternal abdominal acoustic signals. Multichannel, adaptive digital filtering using different frequency characteristics yields a reliable indication of fetal heart beats even at a high level of noise. The evaluation system statistically processes the acoustic signals, controls amplitude limits, and adjusts filter characteristics. Heart-rate variations of as much as 25/min/sec have been accurately registered. High-level integration enables the realization of the method in a very small, belt-mounted instrument with low power consumption, thus convenient for home use. The more than 40 hours of recorded detections stored in the built-in flash memory can be read back into a personal computer for medical inspection and analysis.

Long-term treatment of latent portosystemic encephalopathy with branched-chain amino acids. A double-blind placebo-controlled crossover study

This trial was undertaken to assess the safety and efficacy of long-term oral supplementation with branched-chain amino acids as an adjunct to conventional therapy in patients with stable cirrhosis and latent encephalopathy. Latent encephalopathy was diagnosed by psychometric testing, used to assess automobile driving capacity. Seventeen patients with impaired driving capacity received either branched-chain amino acids or placebo for 8 weeks before being crossed over to the other regimen for an equal period. Branched-chain amino acids but not placebo significantly improved psychomotor disturbances (p < 0.01) and driving capacity (p < 0.002). No adverse reactions were observed. We conclude that long-term branched-chain amino acid supplementation is well tolerated and effective in the treatment of impaired automobile driving capacity associated with latent portosystemic encephalopathy.

Contraction monitoring with a manager calculator

A simple manager calculator was used as a contraction monitor, and external parallel registrations were performed on 10 pregnant women in labor with the Psion and other kinds of tocodynamometers. A 94% correlation was found between the simultaneously registered data.

[The current method of early recognition and treatment of threatened premature labor]

The authors, following a short review of the currently available diagnostic and therapy methods of threatening premature delivery, introduce their own method. The most important feature of this method is a two-level, computerized telecommunicative system. According to the risk factors, physical examination and the patient's complaints (clinical parameters) a risk score analysis is made by the central computer of the outpatient clinic. Those pregnants who fall into the high-risk group are followed-up by means of a portable contraction monitor. The treatment is introduced according to the registered spontaneous contraction activity. (hospitalisation, beta-mimetic etc.). After institution of the therapy the patient can be emitted to her home under the care of the portable monitor. Data of the registered and stored contraction activity from the patient's home can be transmitted to the central computer of the out-patient clinic via phone. If the telephone connection is not possible, the physician can read out the stored data from the memory of the portable monitor on its own display during regular visits. Finally the authors make preliminary cost-benefit calculation on the basis of the literature and their own data and conclude that their method can be very cost effective as well.

[Changes in approach to the delivery of dysmature infants following the introduction of Doppler flowmetry]

The authors studied the clinical history dysmature newborns delivered between 1982-1988. Since the middle of 1985 the fetal circulation in each case has routinely been followed by Doppler flowmetry. With this direct assessment of fetal circulation it is possible to diagnose intrauterine growth retardation and pathologic deviations of fetal circulation at earliest. As a result of this the authors have found an increase in the frequency of terminated pregnancies and caesarean sections. The ratio has been shifted towards pre and dysmature newborns. But on the other hand the frequency of intrauterine deaths has decreased. In all those cases where the dysmature newborn died during the perinatal period there were pathologic flow parameters, as well as malformations in some cases. Further prospective clinical studies of neurological development and disorders of dysmature newborns and children are necessary to decide whether our new point of view has been right or wrong.

[Behavior of the blood vessels of the lung on the roentgen image in children with bronchial asthma--determination of the width of the blood vessels]

On x-ray films of 51 children with asthma bronchiale the authors determined the vascular diameter of the right ascending pulmonary artery, the right vein of the upper lobe, and the peripheral vessels in the upper and lower pulmonary fields at an exactly defined distance from the hilus point, and compared these data with those of a control group of 143 healthy children. During the asthma attack the width of the right descending pulmonary artery and of the vein of the upper lobe corresponded to the values of the control group, whereas the vascular diameters in the upper and lower fields were clearly narrowed. Moreover, in most of the asthmatic children the authors found arc-shaped vessels and irregularly occluded vessels in the periphery of the lungs.

[HLA and thyroid cancer]

HLA typing was performed in 51 patients to analyse the pathogenetic background of differentiated and medullary thyroid carcinomas. A higher incidence of Bw62 and DR5 was observed in patients with papillary carcinoma (n = 24), DRw6 antigen in follicular carcinoma (n = 13), and DR3 antigen in patients with medullary carcinoma (n = 11). The DR3 antigen was present in one of two patients with a familial history of medullary thyroid carcinoma. Therefore, HLA typing is not suitable as a screening method for the detection of early thyroid carcinoma.

[Sjögren syndrome in childhood]

The authors report on the case of a 7-year-old girl with keratoconjunctivitis sicca. The diagnostic difficulties are discussed and the literary data on Sjögren's syndrome in childhood are summarized.

[Hydroxypropylmethyl-containing eyedrops in the treatment of sicca syndrome]

The author reports on 16 patients (9 with keratoconjunctivitis sicca, 7 with Sjögren's syndrome) treated with Isopto-Naturale eye drops for 10 months. Reduction of photophobia, burning, dryness and foreign-body sensation were achieved by local administration of the drug 2 to 5 times a day. The lesions in the corneal epithelium also improved significantly during the treatment period. Thus, Isopto-Naturale eye drops have proved to be more effective than 1% methylcellulose or 1.4% PVA artificial tear eye drops in the treatment of dry-eye syndrome.

Topical nitroglycerin ointment in Raynaud's phenomenon

The purpose of the study was to evaluate the hemodynamics of nitroglycerin ointment in Raynaud's phenomenon. 22 patients (15 women and 7 men aged 25-75 years) suffering from Raynaud's phenomenon were investigated in a double-blind paradigm. Blood flow measurements were performed by venous occlusion plethysmography. Cardiac output was registered by means of impedance cardiography. 800 mg nitroglycerin ointment 2% was applied on one hand only. In the placebo group, finger blood flow, blood pressure, heart rate, and cardiac output did not change significantly. In the group receiving nitroglycerin, finger blood flow increased significantly from 21.6 +/- 6.0 to 31.7 +/- 7.0 ml/100 ml/min. Systolic blood pressure decreased from 126 +/- 4 to 118 +/- 3 mmHg. Cardiac output significantly decreased from 7.3 +/- 0.8 to 6.3 +/- 0.5 l/min. It is concluded that nitroglycerin ointment in Raynaud's phenomenon has a local and a systemic effect as well, because, on the one hand, cardiac output and blood pressure decreased whereas, on the other hand, the increase in finger blood flow was more marked in the treated hand than in the contralateral control fingers.

[Comparison of vascular width and accuracy in the subjective assessment of pulmonary circulation in the roentgen picture of children with left-right shunts]

The authors established a comparative relationship between accuracy of measurement of pulmonary flow and extent of vascular widening in 72 children with Left-Right shunt vitiae; this accuracy of pulmonary flow measurement had been subjectively estimated by 4 investigators without knowing the diagnosis and in comparison to the haemodynamic values (percentage of correct findings). The following procedure was adopted: In a control group of 143 healthy children, we first determined the vascular diameter of the right descending pulmonary artery, of the right upper lobal vein, and of the peripheral vessels in the upper and lower pulmonary fields, at an accurately defined distance from the point of the hilus, and compared with the vascular diameters of the children with left-right shunt, employing the method of discrimination analysis. Comparison of the judgement by the 4 investigators with the degree of increase of the vascular diameters showed an accuracy of 65-100% if the right descending pulmonary artery became wider by 2.6 mm, and an accuracy of 79-95% if the mean vascular width in the right upper field increased by 0.7 mm. The accuracy was 83-94% if the mean vascular width in the right lower field increased by 0.6 mm. Statistical studies also showed that the judgement of the 4 investigators was influenced by different vessels.