Structural characterization of sulfadiazine metabolites using H/D exchange combined with various MS/MS experiments

Two major metabolites and one minor metabolite of sulfadiazine were found in pig manure, using a special combination of different MS techniques like parent and product ion scans, H/D exchange, accurate mass measurement, and MS/MS experiments with substructures. N4-acetylsulfadiazine and 4-hydroxysulfadiazine were identified as major metabolites. N4-acetylsulfadiazine could be verified by H/D exchange and comparison with product ion spectra of a synthetic reference compound. In the case of 4-hydroxysulfadiazine, the majority of possible isomers could be discounted after H/D exchange. Substructure-specific MS/MS experiments with fragment ions and comparison with product ion spectra of two references revealed the presence of 4-hydroxysulfadiazine. The minor metabolite was characterized to some degree using H/D exchange and tandem mass spectrometry in combination with a high-resolution time of flight mass spectrometer. The aminopyrimidine moiety contained an additional modification with a likely elemental composition of C2H4O and no further acidic hydrogen.

Spatial control of high-harmonic generation in hollow fibers

We demonstrate the control of high-harmonic generation in a hollow fiber by shaping the spatial structure of the generating laser pulse. We use a liquid-crystal-based two-dimensional spatial light modulator to control the spatial phase of the driver pulse. An evolutionary algorithm finds the spatial laser phase distribution that is optimal for reaching maximum total harmonic yield and for selectively enhancing the cutoff region of the spectrum. We show that enhacement of harmonic generation is related to coupling into a single fiber mode. Our results directly show that spatial properties of the laser are important parameters in fully controlling the high-harmonic spectrum. It is thus not possible to derive the controllability of the high-harmonic generation from the single-atom response only.

Quantum control by ultrafast polarization shaping

We demonstrate that the use of time-dependent light polarization opens a new level of control over quantum systems. With potassium dimer molecules from a supersonic molecular beam, we show that a polarization-shaped laser pulse increases the ionization yield beyond that obtained with an optimally shaped linearly polarized laser pulse. This is due to the different multiphoton ionization pathways in K2 involving dipole transitions which favor different polarization directions of the exciting laser field. This experiment is a qualitative extension of quantum control mechanisms which opens up new directions giving access to the three-dimensional temporal response of molecular systems.

New concept for the development of a confocal endomicroscope

It is one of modern medicine's top priorities to reduce the stress for the patient during diagnosis and therapy by designing minimally invasive applications of medical techniques. Microsystems technology has always held the key to minimally invasive solutions in surgery and micro-endoscopy. The new measuring system KOMED is currently developed for the application of in-vivo cellular microscopy. This approach is based on the concept of a miniaturised fibre-optical confocal microscope. The application range of this microsensor system includes the minimally invasive optical biopsy for purposes such as the early detection of tumour cells. In this paper the concept of the KOMED system is described, as well as technical challenges to be solved in the project.

A comparison of fibrin sealants in relation to their in vitro and in vivo properties

INTRODUCTION

Fibrin sealants (FS) have been used for many years to facilitate hemostasis and to provide suture support and sealing/adhesion of tissues after surgery. While their composition is similar, different formulations, application devices, and varying concentrations of key components mean that the properties of clots formed by individual FS can be diverse.

MATERIALS AND METHODS

We performed several studies, including animal models, to compare the properties of 12 different commercially available FS/application device combinations using partial liver and kidney resection models to assess hemostatic efficacy and a novel pig skin model to measure adhesive clot strength. The quality of mixing was determined using colored spray images.

RESULTS

Although the FS tested shared the principle of combining fibrinogen and thrombin, major differences were found between the individual preparations with regard to hemostatic efficacy. Two pre-requisites for successful early hemostasis were identified--adequate clottable protein content and the ability of the application device to effectively mix the fibrinogen and thrombin components of the FS. Factor XIII activity was a key determinant in prevention of re-bleeding and premature clot lysis. Furthermore, FS lacking measurable factor XIII activity formed the weakest, softest clots.

CONCLUSIONS

Clearly, all FS are not the same, and their different characteristics may potentially translate into different clinical outcomes. In our studies, while all FS tested performed well on individual parameters, Beriplast P (Aventis Behring) was the foremost FS in consistently providing early hemostasis, minimizing the risk of re-bleeding, and providing strong adhesive clots capable of resisting mechanical forces.

Determination of selected sulfonamide antibiotics and trimethoprim in manure by electrospray and atmospheric pressure chemical ionization tandem mass spectrometry

A method for the determination of sulfonamides and trimethoprim in the complex matrix liquid manure has been developed using reversed-phase liquid chromatography and atmospheric pressure chemical ionization (APCI) tandem mass spectrometry. A comparison was made between electrospray and atmospheric pressure chemical ionization. APCI proved to be more robust and less sensitive to matrix effects. High-performance liquid chromatographic (HPLC) separation of the analytes was achieved in less than 7 min. The compounds were extracted with ethyl acetate and the extracts were cleaned up by solid-phase extraction on an aminopropyl column. Recoveries were not dependent on the concentration level. The mean recoveries were as follows: trimethoprim 79.0%, sulfadiazine 80.5%, N(4)-acetylsulfadiazine 91.0%, sulfamerazine 78.6%, sulfadimidine 77.2% and sulfamethoxazole 82.8%. Linearity was established over a concentration range of 5 to 5000 microg/kg with correlation coefficients greater than 0.99. The method had a limit of quantitation (LOQ) of 5 microg/kg manure.

Characterisation of humic substances using atmospheric pressure chemical ionisation and electrospray ionisation mass spectrometry combined with size-exclusion chromatography

Humic substances were analysed by atmospheric pressure chemical ionisation (APCI) and electrospray ionisation (ESI) mass spectrometry in positive and negative modes. Using APCI the average m/z range of humic substances was reduced 5-fold compared to ESI. High-resolution time-of-flight mass spectrometry revealed the formation of multiply charged molecules in the ESI mode. Moreover, it was possible to obtain daughter ion mass spectra of humic substances by nanospray tandem mass spectrometry. The size-exclusion chromatography elution profile of humic substances was highly influenced by the pH of the analyte solution. By contrast, the pH had no significant influence on the observed mass spectra of humic substances.

The role of vacuolar malate-transport capacity in crassulacean acid metabolism and nitrate nutrition. Higher malate-transport capacity in ice plant after crassulacean acid metabolism-induction and in tobacco under nitrate nutrition

Anion uptake by isolated tonoplast vesicles was recorded indirectly via increased H(+)-transport by H(+)-pumping of the V-ATPase due to dissipation of the electrical component of the electrochemical proton gradient, Deltamu(H+), across the membrane. ATP hydrolysis by the V-ATPase was measured simultaneously after the Palmgren test. Normalizing for ATP-hydrolysis and effects of chloride, which was added to the assays as a stimulating effector of the V-ATPase, a parameter, J(mal)(rel), of apparent ATP-dependent malate-stimulated H(+)-transport was worked out as an indirect measure of malate transport capacity. This allowed comparison of various species and physiological conditions. J(mal)(rel) was high in the obligate crassulacean acid metabolism (CAM) species Kalanchoë daigremontiana Hamet et Perrier, it increased substantially after CAM induction in ice plant (Mesembryanthemum crystallinum), and it was positively correlated with NO(3)(-) nutrition in tobacco (Nicotiana tabacum). For tobacco this was confirmed by measurements of malate transport energized via the V-PPase. In ice plant a new polypeptide of 32-kD apparent molecular mass appeared, and a 33-kD polypeptide showed higher levels after CAM induction under conditions of higher J(mal)(rel). It is concluded that tonoplast malate transport capacity plays an important role in physiological regulation in CAM and NO(3)(-) nutrition and that a putative malate transporter must be within the 32- to 33-kD polypeptide fraction of tonoplast proteins.

Using a matrix-assisted laser desorption/ionization time-of-flight mass spectrometer for combined in-source decay/post-source decay experiments

Mass spectrometric experiments with fragment ions have not yet been possible with a matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometer because intense signals of fragment ions were rarely observed during continuous extraction and the mass resolution of in-source formed fragment ions has been low. This paper describes a combination of MALDI in-source decay and post-source decay experiments on a MALDI-TOF mass spectrometer equipped with delayed extraction. Fragment ions initially formed in the ion source were selected by the precursor ion gate and investigated by post-source decay. The in-source formed fragment ions were sufficiently excited to undergo further metastable decay. The new method was applied to linear peptides, the cyclic peptide gramicidin S and a pentasaccharide, leading to unambiguous structural information.

A strategy for rapid and efficient sequencing of Lys-C peptides by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry post-source decay

A modification procedure for Lys-C peptides is described which simplifies the correct assignment of the amino acid sequence. Release of the C-terminal lysine from Lys-C peptides by carboxypeptidase B and subsequent N-terminal acetylation of the resulting peptides leads to predictable shifts of the C- and N-terminal fragment ions in Matrix-assisted laser desorption/ionisation time-of-flight post-source decay mass spectra and facilitates the correct assignment of mostly complete amino acid sequences for oligopeptides. The derived sequences of peptides from unknown proteins were used to search in databases for homologous protein sequences. Our method was applied to an unknown protein isolated from eggs of Drosophila melanogaster, resulting in the identification of a peptidyl prolyl cis-trans-isomerase.

[Robin-Silverman-Smith (fetal face) syndrome]

Report of a case of the fetal face syndrome associated with severe oligophrenia and septum pellucidum cyste in a male patient aged 30 years. The case demonstrates the good prognosis of the hypogenitalism resp. small genitalia; the correct diagnosis in this syndrome can the patients save a plastic of the penis.

Osteopenia in primary and secondary amenorrhea

This study aimed at investigating the prevalence of osteopenia among a hypoestrogenic group of patients with primary or secondary amenorrhea. Twenty-seven patients with amenorrhea were examined. Sixteen of them presented with secondary amenorrhea (mean age 27.8 +/- 1.9 yrs), and 11 with primary amenorrhea (mean age 21.3 +/- 1.6 yrs). Ten regularly menstruating women (mean age 28.9 +/- 1.4 yrs) served as controls. Estradiol serum levels as well as lumbar spine bone mineral density were measured. All 11 patients with primary amenorrhea showed osteopenia with a mean bone mineral density Z-score of 71 +/- 2% and mean estradiol levels of 30.6 +/- 5.9 pg/ml. The secondary amenorrheic patients were significantly demineralized with a mean Z-score of 82 +/- 3%; 10 of them had osteopenia. Their mean estradiol levels were 34.3 +/- 2.9 pg/ml. The bone density in the primary amenorrheic patients was significantly lower as compared with the secondary amenorrheic women. In comparison, lumbar spine bone density in all control women was normal with a mean Z-score of 104 +/- 3%. In summary, 21 of the 27 patients had osteopenia, higher than that reported in post-menopausal women. Since it is not proven whether the bone mineral deficit of amenorrheic patients can ever be compensated, early diagnostic steps and estrogen-progestogen replacement for the prevention of further bone loss and subsequent fractures are recommended.

Computed tomography in the determination of leg geometry

In 286 adults with misalignment of the lower limb the length and torsional angles of the femur and tibia were determined using a method based on computed tomography. Depending on the location of the axial scan values for femoral antetorsion changed substantially. Normal values obtained in non injured extremities by this technique were an internal torsion of 23.5 +/- 8.6 degrees (mean +/- SD) in the femur and an external torsion of 34.9 +/- 8.6 degrees in the tibia. Mean intraindividual side differences in the femur and tibia were 4 degrees, the 95% confidence interval was 11.0 degrees in the femur and 12.3 degrees in the tibia. CT-methods can only be used for the determination of torsional angles in the femur and tibia if reproducible and standardized locations for the acquisition of axial scans are defined.

[The measurement of the femoral torsion angle in children by NMR tomography compared to CT and ultrasound]

PURPOSE

Anteversion of the femoral neck was measured by MRI in 19 children (37 hips) preoperatively before femoral rotation osteotomies.

MATERIAL AND METHODS

The results of this new technique were compared with values for anteversion obtained by CT and ultrasound. The measurements were performed independently by two observers to determine the correlation between the three different methods and to assess their reliability.

RESULTS

It was possible to show a high correlation coefficient (Pearson) between MRI and CT (r = 0.77) as well as MRI and sonography (r = 0.81). The mean angles obtained by CT (34 degrees, range +5 to +82 degrees) and ultrasound (25.6 degrees, range +10 to +40 degrees) appeared larger than the MRI values (mean angle 23.2 degrees, range 0 to +65 degrees), which can be explained by the different measurement techniques. Mean inter- and intra-variability was low for MRI (r = 0.97 and r = 0.97) and CT (r = 0.99 and r = 0.96) but slightly higher for sonography (r = 0.88 and r = 0.88). MRI is a new reliable and precise method to evaluate femoral anteversion that does not require ionising radiation.

CONCLUSION

MRI is recommended for preoperative planning of paediatric femoral rotation osteotomy patients.

[The value of various ultrasound criteria in objective assessment of acute reactive cholecystitis. A prospective follow-up study of ventilated intensive care patients]

Ultrasound of the abdomen was performed in 30 artificially respirated patients under intensive care conditions for 7 days per patient over a time period of 6 months to elucidate the therapeutic value of different ultrasonographic findings with respect to the diagnosis "reactive acute cholecystitis". Our results show, that neither the detection of concrements or sludge within the gallbladder, nor the transient dilatation of the bile duct, nor a transient wall-thickening or the occurrence of a three-layered wall of the gallbladder can be interpreted as reliable sonographic criteria for the occurrence of an acute reactive cholecystitis. From this we conclude, that reactive acute cholecystitis leading to the indication for cholecystectomy can only be diagnosed from the combination of clinical and sonographic findings. However, reactive acute cholecystitis can almost certainly be excluded, even in obscure upper abdominal symptoms, when the sonogram of the gallbladder is normal.

[The early recognition of infected fluid collections in acute pancreatitis in computed tomography]

Infected accumulations of abdominal fluid are a severe complication and the major cause of death (mortality rate between 20 and 60%) in patients suffering from acute pancreatitis. In 93 patients with confirmed acute pancreatitis including 28 with surgically confirmed pancreatic abscess CT findings (volume of pancreatic and extrapancreatic necrosis, capsular enhancement, gas bubble formation and contact between fluid collection and intestinum) were retrospectively correlated with clinical and operative data to assess abscess formation. This revealed a sensitivity of 0.57 in respect of pancreatic necrosis; for extrapancreatic necrosis the sensitivity was 0.39, for capsular enhancement 0.5, for gas bubble formation 0.46 and for intestinal contact 0.93. The specificity was high for gas bubbles (1.0) and intestinal contact (0.91) and low for the other criteria.

IN CONCLUSION

There is a strong relationship between fluid accumulations in direct contact with intestinal structures and the occurrence of abscess. This parameter enhances the reliability of CT in the early detection of extrapancreatic infection.

[Percutaneous aspiration thromboembolectomy in the treatment of acute occlusion of the lower leg arteries]

Percutaneous aspiration thrombembolectomy (PAT) is a very suitable method for the recanalization of the popliteal and lower limb arteries after embolic occlusion. In thrombotic occlusion in patients with arteriosclerotic disease, PAT can easily be combined with other interventional procedures, yielding good results. With the use of PAT the dose of regionally effective fibrinolytic drugs, which may be additionally administered, can be significantly reduced.

[MRT and dynamic CT in the diagnosis of a recurrence of rectal carcinoma]

A prospective study on 29 patients with presacral lesions after operation of rectal cancer was performed to define the accuracy of CT using a dynamic contrast study and MRI for detection of tumour recurrence (sensitivity) and differentiation from scar formation (specificity). In dynamic CT sensitivity was 88% and specificity was 100%. In MRI the respective data were 94% (sensitivity) and 92% (specificity). Additionally 14 patients with primary rectal cancer were included to define standards for dynamic CT; no differences between primary tumour and relapse were found. In MRI the assessment of signal intensities in T2w images permits differentiation between tumour relapse and scar tissue. In dynamic CT automatically calculated time-density graphs enable differentiation of presacral lesions and the initial increase of density after standardised bolus application was shown to be the most reliable parameter.

Rapid increase in lumbar spine bone density in osteopenic women by high-dose intramuscular estrogen-progestogen injections. A preliminary report

This prospective pilot study has been carried out to assess the effect of high parenteral doses of estrogens and progestogens on lumbar spine bone density in osteopenic women. Thirteen osteopenic women received 40 mg estradiol valerate and 250 mg hydroxyprogesterone caproate by intramuscular injections once a week for 6 months (so called "pseudopregnancy"). One g oral calcium was added. Six out of the 13 patients (49.5 +/- 4.8 y were peri- and postmenopausal = group A. Seven patients (21.5 +/- 2.2 y) suffered from primary and secondary amenorrhea, in 4 out of them due to gonadal dysgenesis = group B. Estradiol was measured by commercial radioimmunoassay. Bone density was determined by dual-energy X-ray absorptiometry (DEXA) of the upper 4 lumbar vertebrae. Lumbar spine bone density as well as estradiol serum levels were measured before and 3 and 6 months after therapy, respectively. Estradiol increased from 34.8 +/- 7.5 pg/ml to 3226 +/- 393 pg/ml after 3 months and to 2552 +/- 254 pg/ml after 6 months, respectively, in group A. Bone density increased by 15.3 +/- 3.6% within the first 3 months to a total of 18.8 +/- 3.9% after 6 months, respectively. Two patients we have controlled for two years, maintained this increase. In group B estradiol increased from 27.8 +/- 6.5 pg/ml to 3028 +/- 728 after 3 and to 2491 +/- 684 pg/ml after 6 months. Bone density in this group increased by 11.8 +/- 1.9% within 3 and to a total of 18.2 +/- 2.8% after 6 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Neem oil inhibits two-cell embryo development and trophectoderm attachment and proliferation in vitro

PURPOSE

The in vitro effect of neem oil was studied on the development of mouse two-cell embryos and trophectodermal cell attachment and proliferation.

METHOD

Female mice were primed with gonadotropins for superovulation and caged with male mice. Early embryos, at the two-cell and the blastocyst stages, were recovered at 40 and 88 hr post-hCG from the oviducts and the uteri, respectively. In the first experiment, two-cell embryos were exposed to culture medium containing different concentrations of neem oil for 1, 12, and 24 hr and then grown in neem oil-free culture medium and assessed for the formation of total and hatching blastocysts at 96 hr. In the second experiment, partially hatching blastocysts were cocultured with human endometrial stromal cell monolayers in culture medium containing different concentrations of neem oil and assessed for the attachment and proliferation of trophectodermal cells at 96 hr.

RESULTS

Exposure of two-cell embryos to neem oil concentrations of 0.050-0.500% for 1 hr, 0.010-0.250% for 12 hr, and 0.005-0.100% for 24 hr caused significant inhibition of the formation of total and hatching blastocysts, in a dose-dependent manner. Neem oil at 0.050-0.100% concentrations inhibited, in a dose-dependent manner, the in vitro attachment and proliferation of trophectodermal cells of partially hatching blastocysts cocultured with human endometrial stromal cells monolayers.

CONCLUSION

Neem oil inhibits the development of two-cell embryos and attachment and proliferation of the trophectodermal cells of partially hatching blastocysts in vitro. The study encourages the use of this herbal product as a postcoital contraceptive that warrants further research.

[Sonographic aspects of clinically suspected acute appendicitis]

Revealing a sensitivity of 97.5% and a specificity of 95.12% this study emphasizes the excellent diagnostic value of sonography in the elucidation of patients with clinical signs of "acute appendicitis". Evaluation of morphology on the one hand and maximal diameter of the organ and the organ wall on the other, in conjunction with the clinical presentation, allows a restrictive management of the surgical treatment and thus decreases the rate of negative laparotomy.