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Biomedical subjects

H Koch

Publications and source records attributed to H Koch.

At least 19 recordsLinked to original sources

Methods for the determination of sulphonamides in meat.

Sulphonamides, due to their important antibacterial effects, are widely used in veterinary practice and animal husbandry. Residues arising from administration without observing withdrawal time sufficiently are normally the parent compounds and the N4-acetyl derivatives, the latter being hydrolyzed to the parent compounds only during extraction under acidic conditions. It is therefore quite conceivable that many authors concentrate on determining these metabolites. In the past decade, we have witnessed a considerable increase in new analytical techniques dealing with the determination of sulphonamides. Among these procedures, especially the so-called multimethods using high-performance liquid chromatography--though sometimes including toilsome clean-up steps--can be mentioned. However, current approaches also utilize gas chromatography, gas chromatography-mass spectrometry, liquid chromatography-mass spectrometry, supercritical fluid chromatography-mass spectrometry, thin-layer chromatography and immunological methods. For most of these techniques, a strong trend towards lowering the level of detectability (down to the sub-ppb range) and improving accuracy and reproducibility can be established.

Animals

Popliteal pterygium syndrome with special consideration of the cleft malformation: case report.

This report describes a new case of popliteal pterygium syndrome (PPS) and also a treatment protocol. The patient presented with the complete complex of PPS and additional abnormalities that have not been described in the literature: a sinus of the upper lip, an extreme hypopoplastic prolabium with aplasia of the vestibule in this area, and a velar pterygium.

Abnormalities, Multiple

[Infections after bone marrow transplantation in childhood].

In 66 children having undergone bone marrow transplantation (BMT) the occurrence of infections was studied retrospectively. Bacterial infections were mostly found in the early period after transplantation before marrow engraftment. The analysis of positive blood cultures showed a dominance of gram-positive bacteria, especially of coagulase-negative staphylococci. Cytomegalovirus (CMV) infections were most important, because of its high rate and the risk of CMV associated interstitial pneumonia (IP), two patients suffered from. Infections from herpes simplex virus (HSV), varizella zoster virus (VZV) and Epstein Barr virus (EBV) had no influence on prognosis. In fungal infections the systemic aspergillosis was the most important complication. To increase the effectiveness and safety of therapy the serum levels of antibiotics and antifungal drugs should be determined.

Adolescent

A skin MR-marker for radiation treatment planning.

After experiences with fluid filled tubes a gel fitted with an adhesive has been developed, to reproducibly markate treatment ports on the patient's skin. A gel is chosen, that hinders loss of the fluid and smoothly fits to the skin surface due to the adhesive. The clinical use of the gel hopefully will help with the use of NMR image information in radiotherapy treatment planning.

Equipment Design

Peritonitis caused by Trichomonas--a preliminary case report.

Trichomonas infections of the abdominal cavity are uncommon and case histories have not been published previously. A patient to whom reference is made this paper developed a combined immunodeficiency syndrome and portal hypertension with ascites on the basis of a cirrhosis of the liver. This seems to have been the precondition for a peritonitis caused by a Trichomonas species.

Ascites

A 37-channel DC SQUID magnetometer system.

A 37-channel DC SQUID magnetometer system has been built for biomagnetic studies. The SQUID loop of each magnetometer serves as the active sensing element, thereby eliminating the need for flux coupling circuits. The magnetometers are located approximately 3 cm above the outer dewar bottom. The SQUIDs are directly coupled to highly simplified read-out electronics using only five wires per channel; no helium temperature impedance matching circuits are required. Each channel can be independently inserted into or removed from the dewar. Using a novel electronic noise reduction technique the system white and 1 Hz flux density noise values are typically 5 and 10 fT Hz-1/2, respectively, including the noise contribution of the in-house fabricated dewar and the magnetically shielded room. The two parts of the data-processing system allow independent handling of the acquisition and analysing task. Two example measurements demonstrate the advantage of the electronic noise reduction method.

Equipment Design

Silymarin, an inhibitor of lipoxygenase.

Silybin (I), silydianin (II) and silychristin (III), the constituents of silymarin, non-competitively inhibit the lipoxygenase from soybeans (EC 1.13.11.12) in vitro.

Flavonoids

Silymarin, an inhibitor of prostaglandin synthetase.

Silybin (I), silydianin (II) and silychristin (III), the main constituents of silymarin, inhibit the formation of prostaglandins in vitro. The inhibition is log-linearly dependent on the concentration of the effectors.

Animals

[Endoscopic papillotomy (author's transl)].

Endoscopic papillotomy is a method of incising the papillary spincters without opening the abdominal wall or the duodenum. It is successful in over 95% of cases. In over 80% of cases passage of choledochus concrement occurs, about half of these stones being excreted spontaneously and the rest having to be extracted actively with a small Domia basket. For large concrements which cannot be removed endoscopically even after wide papillotomy incision, there is the electrohydraulic lithotrite which crushes them so that they can be passed spontaneously or be actively extracted. Dissolution by a substance instilled through a catheter passed through the papilla into the common bile duct is still in the experimental stage. Altogether for this reason endoscopic papillotomy and removal of stones is an advance for the patient at risk, as it involves a lower lethality than the corresponding surgical method.

Ampulla of Vater

Individual messenger RNA half lives in Saccharomyces cerevisiae.

We have measured the decay half-life of functional messenger RNA (mRNA) for some thirty different proteins in the yeast Saccharomyces cerevisiae. Production of newly synthesized mRNA was halted by raising the temperature of a culture of a temperature-sensitive mutant, ts 136. Aliquots of this culture were pulsed-labelled with [35S]-methionine at various times after the temperature shift and the radioactive proteins separated on the two-dimensional gel electrophoresis system of O'Farrell. We find a range in the decay half lives of individual mRNA species which varies from 3.5 min to greater than 70 min. We find three general classes of decay curves, (a) simple exponential (first order); some of these showed a shoulder before onset of exponential decay; (b) bi-component or multi-component concave upward; (c) initial stimulation of rate of mRNA synthesis, followed by virtually undetectable decay.

Electrophoresis

Pharmacokinetics and metabolism of taglutimide (K-2004) in the rat.

Absorption, blood level course, renal, fecal, and biliary elimination and the metabolisation of 2-(bicyclo[2,2,1]-heptane-2-endo-3-endo-dicarboximido)-glutarimide (taglutimide, K-2004), a new hypnotic-sedative substance, were studied in the rat, and the pharmacokinetic constants were calculated. After oral administration of 10 mg per animal, which corresponds to the 7- to 10-fold human dose, a fast and practically total absorption and a quick and complete excretion was observed. Within 1 h 82% of the dose given were absorbed, and 12 h after the dosing 88% had been excreted again. The elimination was effected nearly exclusively (over 95%) via the urine. Besides 10 defined metabolites only 10% of the drug appeared unchanged.

Animals