Small blood volumes from children for quantitative sotalol determination using high-performance liquid chromatography

A sensitive high-performance liquid chromatographic method using fluorescence detection has been developed for sotalol determination in small plasma samples of children and newborns with limited blood volume. In sample sizes of 100 microl of plasma, sotalol was extracted using an internal standard and solid-phase extraction columns. Chromatographic separation was performed on a Spherisorb C6 column of 150x4.6 mm I.D. and 5 microm particle size at ambient temperature. The mobile phase consisted of acetonitrile-15 mM potassium phosphate buffer (pH 3.0) (70:30, v/v). The excitation wavelength was set at 235 nm, emission at 300 nm. The flow-rate was 1 ml/min. Sotalol and the internal standard atenolol showed recoveries of 107+/-8.9 and 97+/-8.1%, respectively. The linearity range for sotalol was between 0.07 and 5.75 microg/ml, the limit of quantitation 0.09 microg/ml. Precision values expressed as percent relative standard deviation of intra-assay varied between 0.6 and 13.6%, that of inter-assay between 2.4 and 14.4%. Accuracy varied between 86.1 and 109.8% (intra-assay) and 95.4 and 103.3% (inter-assay). Other clinically used antiarrhythmic drugs did not interfere. As an application of the assay, sotalol plasma concentrations in a 6-year-old child with supraventricular tachycardia treated with oral sotalol (3.2 mg/kg per day) are reported.

[Yersinia enterolitica infections: 2. Impact on human health]

The clinical picture of yersiniosis in humans and its prevalence in the human population is described in detail. Mass production of animals, development of meat factories based on sophisticated chains of cold storage units and international trade of meat products and animals are believed to be the reasons for the increasing prevalence of yersiniosis in humans. In Germany, anti-Yersinia antibodies are found in up to 40% of the average population. The financial losses for the national economy cannot be judged. Of special interest for industrial medicine are sequelae-like reactive arthritis in exposed occupational groups such as veterinarians or butchers. However, the lack of national and international data makes the assessment of the potential of yersiniosis as a zoonosis difficult. Therefore, intensive and interdisciplinary research is needed to close the gaps described. Already proven and proposed countermeasures at the different stages of mass production of animals and reglementations for international trade of meat products and animals are introduced. The need for development not only of cheap and rapid diagnostic tools but also for countermeasures and treatment strategies is discussed.

Determination of carvedilol in human cardiac tissue by high-performance liquid chromatography

A new high-performance liquid chromatographic method has been developed for the determination of the beta-receptor blocker carvedilol in human cardiac tissue. After homogenizing tissue samples in a microdismembrator, carvedilol and the internal standard naftopidil are extracted with acetone. The extract is evaporated to dryness and reconstituted in a potassium acetate buffer of pH 3.5. Samples are cleaned up with solid-phase extraction columns. Carvedilol and the internal standard show recoveries of 69.8 +/- 12.2% and 63.9 +/- 9.34%, respectively. The linearity range for carvedilol is 0.01-0.35 ng/mg (parts per billion) tissue (wet weight), and the limit of quantitation is 0.01 ng/mg. The percentage coefficient of variation of the intra-assay varies between 1.45 and 5.38% and the interassay between 4.25 and 6.96%. To use as an application of the assay, the cardiac carvedilol tissue level in a patient on oral carvedilol therapy for congestive heart failure is reported.

Tissue differentiation and cytokine synthesis during strain-related bone formation in distraction osteogenesis

To investigate the contributions of various cytokines that are involved in mechanically related bone formation, we applied defined uniaxial strains in a rabbit model of mandibular elongation and examined the regenerating bone during early stages of dist raction osteogenesis by histomorphometry. We also measured serum concentrations of various cytokines during the distraction. Cell proliferation and differentiation indices correlated significantly (P<0.001) with the extent of load application. Serum concentrations of insulin-like growth factor-1 (IGF-1) decreased after osteotomy whereas transforming growth factor beta1 (TGFbeta1) showed a postoperative increase. Prostaglandin E2 (PGE2) concentrations were constant throughout the experimental period. Collagen degradation decreased slightly postoperatively and increased in samples exposed to higher magnitudes of strain. Our data show that it is the magnitude of mechanical strain that decides tissue response by a characteristic cell proliferation and differentiation. The operative trauma leads to inverse changes in serum concentrations of TGFbeta1 and IGF-1, thereby promoting the recruitment of osteoblastic precursor cells as well as collagen matrix synthesis.

Immunodiagnostic identification of dairy cows infected with Prototheca zopfii at various clinical stages and discrimination between infected and uninfected cows

Protothecosis is a severe form of mastitis in cattle that is caused by colorless algae of the genus Prototheca. So far, no suitable serological test for the identification of infected animals is available for routine diagnosis. In this study an indirect enzyme-linked immunosorbent assay (ELISA) for the identification of infected cows and for discriminating among infected cows at various clinical stages was developed. Immunoglobulin G (IgG) in serum and IgA and IgG1 in whey were used as antibody isotypes. The ELISA was evaluated using serum and whey from animals at different clinical stages of infection. A total of 12 cows with acute clinical manifestation of protothecal mastitis, 22 cows with clinical signs of chronic mastitis, 40 Prototheca zopfii-negative cows, and 18 cows with chronic clinical signs and earlier cultures positive for P. zopfii but with presently negative culturing results were investigated. A sensitivity of 96% and a specificity of 94% were calculated for the ELISA based on IgA levels. Intra-assay and interassay variations were calculated to be 6.08 and 6.32%, respectively. Based on these data, this ELISA was found to be suitable for discrimination between infected and uninfected animals and might therefore be useful for screening affected herds.

[Femoro-distal ePTFE bypass grafting using femoro-crural patch prosthesis (FCPP). Results of a prospective clinical study]

Femorodistal bypass using exclusively PTFE is known to have a poor prognosis, mostly because of the development of myointimal hyperplasia (MIH). Several vein patch techniques are established but the role of hemodynamics within the anastomotic site has only been explained insufficiently and is hardly considered clinically. In a prospective study, between 6/1992 and 7/1998 129 patients (89 m/40 f, mean age 65.2 +/- 10.0 years) with critical limb ischemia and no usable saphenous vein were included to undergo femorodistal ePTFE bypass grafting with a new, hemodynamically optimized distal end-to-side anastomosis. Patients were followed at 6-month intervals with clinical investigation and color-coded Doppler sonography. Primary and secondary graft patency (PPR, SPR), limb salvage, and patient survival were calculated according to Kaplan-Meier. With a median follow-up of 45 (range 6 to 72) months, PPR and SPR at 1, 3 and 5 years were 63.0, 35.7 and 27.6% and 74.5, 44.8%, and 37.6%, respectively. Limb salvage at 1, 3 and 5 years was 86.4%, 78.7% und 73.2%. There was no perioperative mortality. Graft infection occurred in 7 patients (5.2%). ePTFE bypass grafting represents a valuable option for infragenicular and crural reconstruction in the absence of autologous vein. The new anastomotic design was feasible and represents another adjunct to possibly improve patency of femorodistal bypass allografts.

Expression and tissue localization of soluble guanylyl cyclase in the human placenta using novel antibodies directed against the alpha(2) subunit

The cytoplasmic or soluble forms of guanylyl cyclase (sGC) are heme-containing heterodimeric enzymes that are regulated by nitric oxide (NO) and carbon monoxide (CO). These gaseous messenger molecules are produced in the human placenta and are potential regulators of vasodilation and trophoblast invasion. The alpha(2)-subunit of sGC has only recently been shown to naturally occur in placental extracts. In the present study, two novel antibodies directed against different epitopes of the alpha(2) subunit, were generated. Western Blot analysis confirmed the presence of a 82 kDa protein, identical with alpha(2) protein overexpressed in Sf9 cells. According to RNase protection analysis the alternatively spliced alpha(2i) variant was absent from human placenta. Immunohistochemical analysis showed the presence of alpha(2) protein in syncytiotrophoblast and villous and umbilical blood vessels, which are known sites of NO production. Strong expression was observed in the extravillous (intermediate) trophoblast, where the expression of CO-generating hemeoxygenases has recently been documented. Localization of alpha(2) subunit expression suggests a role for sGC in mediating the actions of both NO and CO. The novel antibodies characterized in the present study will be powerful tools to further elucidate the role of the NO/CO/cGMP signaling pathways in pathologic states such as preeclampsia and intrauterine growth retardation.

[Diagnosis o Yersinia enterocolitica infections: a review on classical identification techniques and new molecular biological methods]

Only three of the eleven species of the genus Yersinia are associated with disease. Y. pestis is the causative agent of plague, Y. pseudotuberculosis and several pathogenic bio/serovars of the species Y. enterocolitica cause yersiniosis. New Y. enterocolitica subspecies with diagnostic relevance have been proposed allowing the differentiation of European and American isolates. The ISO-standard (ISO 102739) summarizes the knowledge gained from enrichment and isolation of Y. enterocolitica from food and feed samples. The final biochemical identification must be carried out by classical tube testing, as commercially available test-systems are not sensitive and specific. For the assessment of the presumptive pathogenicity of a Y. enterocolitica isolate empiric virulence markers can be replaced by PCR assays targeting plasmoidal or chromosomal genes. Their evaluation in terms of routine diagnostic procedures is still missing. The definite identification of Y. enterocolitica isolates can also be achieved by sequencing the 16S rRNA gene. Immunoblot based on plasmoidal encoded Yersinia proteins enables the serological determination of animal and human infections. The development of simple, sensitive and specific rapid identification systems applicable for the direct and indirect diagnosis for veterinary use is a challenge for the future.

[Yersinia enterocolitica infections: 1. Impact on animal health]

In Europe, yersiniosis is mainly caused by the bacterial species Yersinia enterocolitica. The clinical picture of yersiniosis in farm animals including pig, chinchilla, cattle, small ruminants and the pet animals dog and cat is described in detail. However, data on seroprevalence and prevalence in these animals are not available. Therefore, further research is needed in the fields of epidemiology and epizootiology.

Effect of intravenous iloprost and alprostadil (PGE1) on peripheral resistance during femoro-distal reconstructions

BACKGROUND

A prospective, randomised study was undertaken to investigate the effect of intravenous infusion of either iloprost, the stable prostacyclin (PGI2) analogue, or alprostadil (prostaglandin E1) on peripheral resistance (PR) during femoro-distal reconstruction.

METHODS

A prospective randomised study was performed with 35 patients. The PR Measurement of peripheral resistance involved a silicon tube temporarily inserted between the donor and recipient vessel. A flowmeter probe and a pressure transducer were inserted into the tube. The peripheral resistance was calculated as a quotient of pressure and flow under approximate physiological conditions. Patients received either alprostadil (4.4 ng/min/kg) or iloprost (2 ng/min/kg) intravenously over ten minutes. After the end of the infusion, the measurements were taken for five minutes.

RESULTS

Baseline peripheral resistance was similar for both groups (iloprost 0.76+/-0.54 mmHg/ml/min, alprostadil 0.72+/-0.35 mmHg/ml/min, p>0.05). Following the measurement procedure, the final peripheral resistance in the iloprost group was reduced (0.57+/-0.33 mmHg/ml/min), but the difference to the alprostadil group (0.70+/-0.36 mmHg/ml/min) was not significant (p>0.05). The different decrease of ratio peripheral resistance (quotient between final and baseline resistance times one hundred) was highly significant (iloprost: 79.4+/-13.4% vs alprostadil: 97.0+/-15.6%, p<0.01).

CONCLUSIONS

Intravenous application of prostanoids, infused with usual doses over ten minutes during femoro-distal reconstructions, produces significant differences in decrease of peripheral resistance. Alprostadil only causes a slight drop of resistance, whereas iloprost causes a significant higher reduction of peripheral resistance.

Genetische Analyse der kongenitalen Hypotrichose mit Anodontie beim Rind

Abstract. Title of the paper: Genetic analysis of congenital hypotrichosis with anodontia in cattle In three male German Holstein calves, black and white spotted, congenital hypotrichosis and nearly complete anodontia was observed. The pedigree of the probands being maternal halfsibs and grandmatemal grandsons supports a monogenic, X-linked recessive inheritance. Chromosomal Xq-deletions were not detected. Similar congenital anomalies are known in tabby mice and in humans as anhidrotic ectodermal dysplasia (EDI, EDA). The human gene causative for EDI and the Tabby gene are located on the X-chromosome. Therefore, the moleculargenetic marker analysis in our material was restricted on the X-chromosome. Using identical by descend mapping based on 20 microsatellites, we were able to identify an exclusively Joint genomic region on the long arm of the X-chromosome among the affected calves. The putative location of the gene locus for congenital hypotrichosis with anodontia maps into the region of the marker BM4604 on position 76.5 cM of the X-chromosome.

Myocardial contractility after infarction and carnitine palmitoyltransferase I inhibition in rats

Inhibition of carnitine palmitoyltransferase I with etomoxir increases sarcoplasmic reticulum Ca(2+)-transport and V(1) isomyosin expression. To test whether etomoxir attenuates contractile dysfunction after myocardial infarction, we compared the contractility of papillary muscles from etomoxir- and placebo-treated rats 6 weeks after infarction. Etomoxir induced cardiac hypertrophy in animals with small infarctions, and enhanced compensatory heart growth at large infarct size. Contractile function of papillary muscles from etomoxir-treated rats was improved particularly in animals with small infarctions. Thus, induction of mild cardiac hypertrophy by etomoxir in rats with small infarctions may be beneficial for myocardial performance.

Functional ethanol tolerance in Drosophila

In humans, repeated alcohol consumption leads to the development of tolerance, manifested as a reduced physiological and behavioral response to a particular dose of alcohol. Here we show that adult Drosophila develop tolerance to the sedating and motor-impairing effects of ethanol with kinetics of acquisition and dissipation that mimic those seen in mammals. Importantly, this tolerance is not caused by changes in ethanol absorption or metabolism. Rather, the development of tolerance requires the functional and structural integrity of specific central brain regions. Mutants unable to synthesize the catecholamine octopamine are also impaired in their ability to develop tolerance. Taken together, these data show that Drosophila is a suitable model system in which to study the molecular and neuroanatomical bases of ethanol tolerance.

Short-course antibiotic treatment of 4782 culture-proven cases of group A streptococcal tonsillopharyngitis and incidence of poststreptococcal sequelae

A large-scale study with a 1-year follow-up was performed to compare 10 days of penicillin V with a short-course treatment (5 days) of other oral antibiotics in the treatment of group A beta-hemolytic streptococcus (GABHS) tonsillopharyngitis, to evaluate the efficacy and the incidence of poststreptococcal sequelae. The clinical response rates after completion of therapy were 94.5% in the 5-day group and 93.4% in the penicillin group (P<.001, equivalence test). The GABHS eradication rates were 83.3% in the 5-day group and 84.4% in the penicillin group (P=.022, equivalence test). Poststreptococcal sequelae were rare (5 patients) and did not occur in the context of this study. The efficacy of 5-day antibiotic regimens was equivalent to 10 days of penicillin V, but resolution of clinical symptoms was faster in the 5-day group (P<.001, Fisher's exact test). Recurrent tonsillopharyngitis occurs more frequently after treatment with penicillin (P=.03, Fisher's exact test).

Femorodistal PTFE bypass grafting for severe limb ischaemia: results of a prospective clinical study using a new distal anastomotic technique

OBJECTIVES

To analyse graft patency and limb salvage following femorodistal bypass with ePTFE using a new distal anastomotic technique. Design prospective non-randomised study.

MATERIAL AND METHODS

One hundred and twenty-nine patients (M:F; 2.23:1; mean age 65.2+/-10.0 years) underwent 135 operations for severe limb ischaemia. The new anastomosis, constructed entirely from ePTFE, was attached to the popliteal (21), anterior (46) and posterior (52) tibial, and peroneal (16) arteries. Cumulative primary (PPR) and secondary patency rates (SPR), limb salvage and survival were analysed using the Kaplan-Meier method.

RESULTS

Median follow-up was 45 (range 6 to 72) months. There was no perioperative mortality. PPR and SPR at 1, 2, 3, 4, and 5 years were 63.0%, 44.9%, 35.7%, 33.1% and 27.6% and 74.5%, 55.2%, 44.8%, 43.0%, and 37.6%, respectively. Cumulative limb salvage was 86.4%, 78.7%, and 73.2% at 1, 3, and 5 years, respectively.

CONCLUSIONS

This new anastomotic design was feasible and resulted in acceptable long-term results.

The transposable element IS4712 prevents S-layer gene (sbsA) expression in Bacillus stearothermophilus and also affects the synthesis of altered surface layer proteins

Cell surface (S)-layer protein synthesis in Bacillus stearothermophilus PV72/p6 is blocked when cells are grown at elevated temperature. From a culture exhibiting the S-layer-negative phenotype, the S-layer deficient mutant T5 (SbsA-) was isolated. Genetic analysis of the S-layer-encoding gene (sbsA) of mutant T5 revealed an insertion element (IS4712) integrated into the upstream regulatory region of the S-layer gene, thereby blocking sbsA transcription. The insertion element consists of 1371 base pairs which are flanked by two perfect inverted terminal repeats. Sequence similarity to other transposases of the IS4 family was detected. DNA-DNA hybridizations demonstrated that multiple homologues of IS4712 were also present within the genomes of several other thermophilic bacillus isolates. Attempts to isolate SbsA+ revertants failed. Instead, cells with altered surface proteins were detected. The synthesis of the altered S-layer proteins was correlated with the presence of IS4712 along with the occurrence of deletions in the sbsA coding region. Furthermore imprecise excision of IS4712 was detected. This work demonstrated that B. stearothermophilus is able to express at least four different S-layer proteins and that blocking of sbsA transcription by the insertion element IS4712 is associated with the expression of altered surface proteins.

[Not Available]

Using the long term rumen simulation technique RUSITEC a possible relationship between Mucor racemosus and Ulocladium chartarum and cerebrocortical necrosis (CCN) in cattle was investigated. In phase one only M. racemosus or U. chartarum and in phase two M. racemosus or U. chartarum in combination with thiamine were tested. The following differences between test groups and controlls could be noted: sVFA -7,5%, cellulase activity +62,1%, protein concentration -16,4%, thiamine -11% (only phase two). Thus, although a clear influence of M. racemosus and U. chartarum on rumen fermentation could be shown, a relation to CCN was not detected.

[Not Available]

The influence of moulded hay (Alternaria alternata, Epicoccum nigrum, Mucor racemosus, Ulocladium chartarum) and the efficiency of Vitamin B1 substitution to cope these effects on rumen protozoa was investigated using the longterm rumen simulation technique (RUSITEC) for about 25 days. Moulded hay affected medium-sized protozoa to a different extent (Alternaria alternata: -16 %, Epicoccum nigrum: -27 %, Mucor racemosus: -9 %, Ulocladium chartarum: +2 %). The vitamin B1 substitution had positive effects during the feeding of Mucor racemosus and Ulocladium chartarum.

[Palivizumab--a monoclonal antibody for passive immunoprophylaxis of respiratory syncytial virus infections]

RSV is the most common cause of lower respiratory tract infections in infants. The humanised monoclonal antibody has been developed for prevention of serious lower respiratory tract disease caused by RSV. Palivizumab specifically inhibits subtypes A and B. In a large, multicenter, double-blind, randomised trial in 1502 infants at high risk of RSV infection, intramuscular palivizumab 15 mg/kg reduced the incidence of RSV-attributable hospitalization by 55% compared with placebo. Palivizumab was well tolerated. In Germany palivizumab prophylaxis should be considered only for high risk premature infants and high risk infants with chronic lung disease if the local rate of hospitalization attributable to confirmed RSV infection is frequent.

Oxygen radical system in chronic infarcted rat heart: the effect of combined beta blockade and ACE inhibition

In vitro experiments suggest that beta blockade and angiotensin-converting enzyme (ACE) inhibition may protect the failing heart by reduction of myocardial oxidative stress. To test this hypothesis in an in vivo model, the beta blocker metoprolol (350 mg) and the ACE inhibitor ramipril (1 mg) were given either alone or in combination to rats (per kilogram body weight per day) for 6 weeks after myocardial infarction. Left ventricular end-diastolic pressure (LVEDP), contractile function of papillary muscles, enzymatic antioxidative defense (indicated by the activities of the superoxide dismutase isoenzymes and glutathione peroxidase), and the extent of lipid peroxidation were studied. Placebo-treated rats showed cardiac hypertrophy, increased LVEDP, lower rates of contraction and relaxation, as well as a deficit in the myocardial antioxidative defense associated with increased lipid peroxide levels, when compared with sham-operated animals. Combined beta blockade and ACE inhibition improved the antioxidative defense, reduced hypertrophy and LVEDP, and enhanced rates of contraction. Thus prolonged beta blockade and ACE inhibition after infarction may decrease myocardial oxidative stress and thereby could be beneficial in heart failure.

Expression of nitric oxide-sensitive guanylyl cyclase subunits in human corpus cavernosum

The muscles of the corpus cavernosum of the penis relax in response to stimulation of non-adrenergic, non-cholinergic nerves or nitric oxide (NO)-donating drugs to elicit erection. It is generally assumed that NO mediates this effect via activation of soluble guanylyl cyclase and a subsequent increase in cyclic guanosine 3', 5'-monophosphate concentration. However, there are no data on the expression of this enzyme in human corpus cavernosum. The purpose of the present study was the molecular characterization of NO-sensitive guanylyl cyclase in human corpus cavernosum. RNA was extracted from tissue samples obtained from seven patients undergoing penile prosthetic surgery or correction of penile deviation. Reverse transcriptase-polymerase chain reaction (RT-PCR) with specific primers for the subunits of NO-sensitive guanylyl cyclase was performed, and PCR products were subcloned and sequenced. Specific amplification products encoding the alpha(1), beta(1), alpha(2), and beta(2) subunits were detected. In addition, we isolated a transcript encoding a novel variant beta(2) subunit. To test whether this novel transcript arises by alternative splicing or whether it is encoded by a separate gene, a 4000-bp clone of the corresponding genomic DNA sequence was isolated. Sequence analysis suggests that the novel beta(2) variant arises by alternative splicing from the same gene as the beta(2) subunit on chromosome 13. In conclusion, our findings suggest the presence of different subunit mRNAs of NO-sensitive guanylyl cyclase in human corpus cavernosum.

Mechano-electric feedback in right atrium after left ventricular infarction in rats

Left ventricular myocardial infarction (MI) can lead to alterations in hemodynamic load conditions, thereby inducing right atrial hypertrophy and dilatation associated with phenotypic modulation of cardiomyocytes, electrical abnormalities, rhythm disturbances, and atrial fibrillation. However, there is limited information on the electrophysiological basis for these events. We investigated whether atrial stretch in the setting of chronic MI modulates the electrophysiological properties of cardiomyocytes via "mechano-electric feedback", providing a mechanism for atrial arrhythmia after ventricular infarction. Five weeks after left ventricular MI (n=37), action potentials (AP) were measured in right atrial tissue preparations using a current clamp scheme, and compared to sham-operated rats (SO, n=10). Contractile activity was recorded at a preload of 1 mN, and sustained stretch was applied via a micrometer. In SO, stretch of 1.75 mN shortened repolarization at 50% and prolonged it at 90%. In MI, mechanically-induced electrical alterations were observed at a significantly lower level of stretch than in SO (0.19 mN). Sustained stretch in MI prolonged AP at 90% repolarization giving rise to stretch-activated depolarizations (SAD) near 90% repolarization (SAD90). When reaching threshold for premature APs, electrical phenomena similar to atrial fibrillations were seen in some preparations. Moreover, we observed APs with prolonged duration at 25%, 50%, and 90% repolarization where stretch induced SAD near 50%. Gadolinium used at a concentration to inhibit stretch-activated channels (40microM) suppressed mechanically-induced electrical events. In conclusion, increased susceptibility after MI to mechanical stretch may predispose atrial cardiomyocytes to arrhythmia. These mechano-electrical alterations are sensitive to gadolinium suggesting involvement of stretch-activated ion channels.

Effects of metoprolol and ramipril on action potentials after myocardial infarction in rats

The effects of chronic treatment with the beta-adrenoceptor antagonist metoprolol, the angiotensin converting enzyme inhibitor ramipril, their combination, or placebo on action potential configuration 6 weeks after myocardial infarction in rats were studied. Action potentials were measured in isolated left ventricular posterior papillary muscles and compared with action potentials from a sham operated group without infarction. After infarction, the action potential amplitude was reduced and this phenomenon was partially reversed by metoprolol- and ramipril-treatment. Prolonged repolarisation after infarction compared to sham operated animals was additionally delayed after metoprolol treatment. Thus, metoprolol extends the refractory period, which may counteract tachyarrhythmia.