Adsorption of creatinine to Fuller's earth

In search for a secondary reference method for the determination of creatinine, the adsorption of creatinine to seven different commercial batches of Fuller's earth have been investigated. Mineralogical investigation of the batches broadly divided them into two subgroups with quite different cation exchange capacities (CEC): dominant smectitic with and without calcium carbonate and dominant palygorskitic with calcium carbonate. Adsorption experiments using 14C-creatinine show, for all Fuller's earth samples, an incomplete adsorption of creatinine. The amount of creatinine adsorbed depends on pH, temperature, concentration of cations as Ca2+ and Na+, and other conditions. Weakly acidic suspensions of Fuller's earth in the course of time change their ability to adsorb creatinine. Compared to a synthetic strong acidic cation exchanger, Fuller's earth is more selective to creatinine. Because of the sensitivity of the adsorption to the various experimental conditions a determination of creatinine in biological fluids using Fuller's earth is too variable. Therefore, we cannot recommend this procedure as a secondary reference method for the determination of creatinine.

Quantitative Determination of Seco-Iridoid Glucosides from the Fruits of Ligustrum vulgare by HPLC

A HPLC method for separation and quantitative determination of secoiridoid glucosides in fruit extracts from LIGUSTRUM VULGARE L. is described. A system using a reversed phase column and an ethanol-water gradient elution, was suitable for separation of Ligstroside, Oleuropein, Nüzhenide and LF (3) 8. The secoiridoid glucosides were detected at 235 nm. The detection limits were within 2 and 10 microg/ml. Ripe fruits yield about 8.85% of secoiridoid glucosides (dried weight).

[Results of percutaneous transhepatic drainage of the bile ducts]

From September 1980 to December 1986, 72 percutaneous transhepatic cholangiography drainages (PTCD) were performed in 64 patients (58 palliative in malignant obstructions, 14 temporary). The median duration of drainage was 26.8 days (2-183 days). The median survival time in 37 patients with palliative tumour drainage was 55.3 days (7-473 days). 9/37 patients survived longer than 3 months (max. 15.5 months). Complications occurred in 29.5% (10.3% severe). 3/64 patients (4.7%) died. Patients with palliative transpapillary drainages (23), especially with endoprostheses (14), survived longer, and the complication rate was lower. Therefore, we prefer the endoscopic transpapillary approach. PTCD patients must be selected carefully.

[Results of 108 endoscopic papillotomies]

At the Medical Clinic of the St. Elisabeth Krankenhaus, Cologne, 108 endoscopic papillotomies (EPT) were carried out between September 1977 and May 1983; 90% have been successful. Choledocholithiasis in 91 patents (84,2%) was the most frequent indication. Approximately half of the cases had had previous cholecystectomy; in the other half the still existing gall-bladder contained stones. These latter patients were definite risk-patients; their average age was 16 years above that of patients with previous cholecystectomy. Other indications have been the inflammatory (14 patients) or tumorous stenosis (3 patients) of the papilla. Complications occurred with 8 patients (7,4%); mortality-rate: 1,9%. The good results and the low rate of complications make EPT the method of choice in case of residual or recurring stones after cholecystectomy as well as in case of risk patients with existing gall-bladder and stones in the common bile duct. Further indications have been: malignant or benign papillary stenosis and acute emergency situations (acute biliary pancreatitis or cholangitis through a stone blocking the duct). The nasobiliary permanent probe, the possibility of direct litholysis, the dilatation by catheter and prolonged draining of stenosis open new applications.

Orotic acid sodium salt in kidney stones and urinary deposits

Kidney stones from a plaice, Pleuronectes platessa, have been shown to consist of the sodium salt of orotic acid. Precipitation of orotic acid in human kidneys and urine samples has previously been reported but the precipitates must have been salts, most likely the sodium salt, of orotic acid and not the free acid. This reinterpretation is based on the acid strength of orotic acid and on data for the solubilities of sodium orotate and orotic acid. Sodium orotate is therefore a member on the list of compounds present in human urinary deposits and calculi. X-ray powder diagrams and d-values and IR-spectra of the sodium salt are recorded to facilitate future identifications.

Criteria for the standardization of Salmonella mutagenicity tests: results of a collaborative study. II. Studies to investigate the effect of bacterial liquid culture preparation conditions on Salmonella mutagenicity test results

The influence of various parameters and growth conditions in the "overnight culture" of Salmonella typhimurium strains on mutagenicity test results was investigated. A number of factors were first suspected to be of some importance for the quantitative outcome of the mutagenicity test. None of them, however, was found to influence the results to such a marked extent as to be a major source of variability. Only the brand of nutrient broth used for the propagation of the bacteria proved finally to have a certain effect on the number of (spontaneous and induced) revertant colonies, although no precise and quantitative statements can be made with regard to a possible standardization of this experimental segment in the Salmonella mutagenicity test. The occurrence of such unpredictable but noticeable influences is, however, evidence for the importance of an intralaboratory optimization and standardization of all parts of the test procedure.

Estradiol-induced synthesis of vitellogenin. III. The isolation and characterization of vitellogenin messenger RNA from avian liver

The messenger RNA of the hormone-induced protein vitellogenin was isolated from the liver of estrogen-treated roosters. Starting from total polysomal RNA, the vitellogenin messenger was purified 67-fold by oligo (dT)-cellulose chromatography and sizing on a sucrose gradient. The messenger was translated in vitro into a 170 000 dalton polypeptide chain, having the immunochemical characteristics of vitellogenin. From electrophoretic and immunochemical analysis of the in vitro product of translation at least 63% of the messenger activity of the RNA preparation could be attributed to vitellogenin mRNA. Gel electrophoresis of the most purified fraction revealed residual contamination with the larger ribosomal RNA species. The molecular weight of the messenger RNA molecule, obtained by contour length measurements in the electron microscope, lies between 2.5 - 10(6) and 2.8 - 10(6).

The regulation of RNA synthesis and processing in the nucleolus during inhibition of protein synthesis

The effect of protein synthesis inhibition by cycloheximide on nucleolar RNA synthesis and processing has been studied in HeLa cells. Synthesis of 45S RNA precursor falls rapidly after administration of the drug. However, the nucleolar content of 45S RNA remains relatively constant for at least 1 hr because the time required for cleavage of the precursor molecule into its products is lengthened after treatment with cycloheximide. The efficiency of transformation of 45S RNA to 32S RNA remains constant with approximately one molecule of the 32S RNA produced for each cleavage of a molecule of 45S RNA. However, shortly after the cessation of protein synthesis the formation of 18S RNA becomes abortive. The amount of 32S RNA present in the nucleolus remains relatively constant. After long periods of protein synthesis inhibition the 28S RNA continues to be synthesized and exported to the cytoplasm but at a greatly reduced rate. When the protein synthesis inhibitor is removed, a prompt, although partial, recovery in the synthesis rate of 45S RNA occurs. The various aspects of RNA synthesis regulation and processing are discussed.

Giant nucleoplasmic RNA in the switch-on of compensatory renal growth

Heterogeneous RNA (HnRNA) (ca. 10S-70S) labeled for ten minutes with (3)H-uridine was identified by polyacrylamide-gel electrophoresis in the nucleoplasm of kidney cells. In the region >28S several discretely migrating species were present. Ten minutes after the removal of one kidney, labeled HnRNA >28S ("giant" HnRNA) in the remaining kidney began to decrease, and by 60 minutes it had fallen drastically. The presence of labeled giant HnRNA during a pulse label after uninephrectomy and its disappearance after longer labeling suggest that the decrease is a consequence of faster processing. Accelerated processing of giant HnRNA is antecedent to the increased synthesis of renal cytoplasmic RNA that follows uninephrectomy.