Monoethylglycinexylidide formation kinetics: a novel approach to assessment of liver function

A novel quantitative liver function test is described which is based on monoethylglycinexylidide (MEGX) formation after lidocaine bolus injection. Following the administration of small single doses of lidocaine hydrochloride (1 mg/kg), monoethylglycinexylidide serum concentration-time curves were determined by a novel highly sensitive fluorescence polarisation immunoassay (FPIA) in healthy volunteers, liver donors and patients with liver cirrhosis. The FPIA allowed rapid and reliable monoethylglycinexylidide determinations in serum and urine (between-days coefficient of variation: less than 10.3%, recovery: 80-113%). Monoethylglycinexylidide concentrations measured by FPIA in 32 serum samples from patients correlated well those determined by HPLC. The monoethylglycinexylidide concentration in serum determined 15 min after a lidocaine bolus injection proved to be a highly sensitive and specific indicator of hepatic dysfunction. Average monoethylglycinexylidide concentrations in serum obtained 15 min after lidocaine injection were substantially lower in patients with liver cirrhosis than in healthy volunteers. The average monoethylglycinexylidide concentrations in serum were also substantially lower in liver donors with ballooning or fatty changes of hepatocytes than in donors without relevant alterations of liver histology. By means of monoethylglycinexylidide formation in the liver donors, primary function of the transplanted liver was correctly predicted in 32/37 cases and initial non-function in 4/6 cases.

[Chemical synthesis of phenylbutazone hydroperoxide and testing of the substance for heart action under in vitro and in vivo conditions]

Phenylbutazone (4-n-butyl-1,2-diphenyl-pyrazolidine-3,5-dione) 1 is an easily autoxidable substance which forms a crystalline and stable hydroperoxide 3. The decomposition of 3 yields products which were investigated as metabolites of the drug. In isolated heart preparations of guinea pigs and rabbit hearts in vivo the hydroperoxide 3 shows a significantly stronger cardiodepressive and coronary constricting effect compared to phenylbutazone 1, 4-hydroxy-phenylbutazone 4 and the open-ring decomposition product of the hydroperoxide 5. The results indicate the significance of the hydroperoxide 3 for the total efficiency of phenylbutazone and explain the side effects of the substance.

Interactions of the histamine H2-receptor antagonist etintidine with rat liver cytochrome P-450: a comparison with cimetidine

The two imidazole histamine H2-receptor antagonists etintidine and cimetidine interact with the rat liver microsomal cytochrome P-450. From type II spectral changes follows that the affinity of rat liver microsomal preparations for etintidine is about 5 times as high as for cimetidine when comparing both high and low affinity binding sites. After pretreatment with phenobarbital etintidine inhibited benzphetamine N-demethylation competitively (app. Ki: 4.0 mmol/l). Cimetidine inhibited benzphetamine N-demethylation in the same range. After pretreatment with phenobarbital both drugs inhibited the oxidation of benzo(a)pyrene for which etintidine showed a higher inhibitory potency than cimetidine. However, this oxidation could not be inhibited when microsomes of 5,6-benzoflavone pretreated rats were used. After pretreatment with 5,6-benzoflavone only etintidine but not cimetidine inhibited the O-deethylation of ethoxyresorufin competitively (app. Ki: 0.2 mmol/l). Etintidine and cimetidine were metabolized by rat liver microsomes to their corresponding sulphoxides. In conclusion, etintidine may cause mainly the same drug interactions as cimetidine but seems to be a more potent inhibitor.

Peptide uptake by astroglia-rich brain cultures

Uptake of carnosine has been investigated in astroglia-rich primary cultures derived from brains of newborn mice. It could be demonstrated that carnosine is not degraded by these cells but rapidly taken up in an energy- and sodium-dependent process. Uptake and release of carnosine by these cells were found to be mediated by a saturable, high-affinity transport system with apparent kinetic constants of Km = 50 microM and Vmax = 22.7 nmol X h-1 X mg protein-1. Uptake of carnosine is strongly inhibited by other dipeptides as well as by various oligopeptides, e.g., Leu-enkephalin. However, uptake of the radiolabeled tripeptide D-Ala-L-Ala-L-Ala was not observed. Radiolabeled Leu-enkephalin also did not accumulate intracellularly, even if degradation of the peptide was prevented by use of peptidase inhibitors. These results suggest that uptake of carnosine is catalyzed by a dipeptide-specific transport system with broad substrate specificity. With neuronal cells in primary culture, uptake of carnosine or other peptides was not observed.

Selective in situ pancreatic perfusion via chronic in vivo celiac artery catheterization

A new technique to catheterize the celiac artery has been developed. This has opened the possibility for direct in vivo, in situ study of pancreatic endocrine cell function in a conscious experimental animal. The catheter is small, soft and placed without arterial ligation so that celiac artery, hepatic, splenic, and pancreatic blood flows were essentially not compromised. Arterial vessel integrity, absence of inflammation, and thrombosis as well as catheter patency were achieved for periods exceeding eight months. Metabolically and hormonally, the presence of the catheter had no effect on the fasting status. However, we found somewhat lower glucose levels and higher insulin levels in the response to oral glucose challenges after catheterization, but these differences were statistically not significant. Glucose loads of 50 mg/kg (0.75 g) administered directly to the pancreas via the celiac artery produced peak insulin levels similar to peripheral glucose loads some tenfold larger. We suggest that this technique may be useful to selectively study the first-pass pancreatic response to a variety of hormones, drugs or metabolic substrates.

Physiological relationships between growth hormone level, glycemia and metabolic control in dogs

This study was undertaken to explore the physiological relationships between fasting glycemia, antecedent glycemic control and fasting growth hormone levels in pancreatectomized dogs. In contrast to other studies, we used continuous intravenous infusions of insulin in an attempt not only to normalize fasting plasma glycemia but also to eliminate the characteristic fluctuations of diabetes usually encountered in the postprandial and postabsorptive periods. For comparison, a similar group of healthy animals served as normal controls. In the healthy dogs, fasting growth hormone (GH) levels were stable and well within normal limits for this species, demonstrating an overall mean +/- SD of 2.50 +/- 0.46 ng/ml. In the pancreatectomized group as a whole, the fasting GH levels were significantly elevated (4.63 +/- 2.42 ng/ml, P less than 0.01) and significantly (P less than 0.001) more variable than in the controls. Multiple regression and analysis of variance confirmed the expected significant positive correlation between fasting GH and fasting plasma glucose levels, but also elucidated a heretofore unknown direct relationship between fasting GH levels and the preceding instability of glycemic control.

Transcriptional activities of mammalian genomes at sites of recombination with foreign DNA

The nucleotide sequences of several sites of recombination between adenovirus DNA and hamster, mouse, or human cell DNAs were determined. These sites of recombination had been cloned from adenovirus type 2 (Ad2)- or type 12 (Ad12)-transformed cells, from Ad12-induced tumor cells, or from a symmetric recombinant between Ad12 DNA and human cell DNA. One important precondition for the generation of recombinants between host and foreign DNAs might be the establishment of a chromatin configuration that permits access of foreign DNA and of the recombination machinery to cellular DNA. Such favorable chromatin structures might arise during cellular DNA replication or transcription or both. As a first approach toward investigating these more complex problems of foreign DNA insertion, we determined transcriptional activities of cellular DNA sequences at viral junction sites. The sites of linkage investigated in this study with respect to their transcriptional activities were those previously cloned and sequenced (W. Doerfler, R. Gahlmann, S. Stabel, R. Deuring, U. Lichtenberg, M. Schulz, D. Eick, and R. Leisten, Curr. Top. Microbiol. Immunol. 109:193-228, 1983). In addition, a site from cell line HA12/7 which is described in this paper was also analyzed. The results presented demonstrate that the cellular DNA sequences involved in linkage to viral DNA at five completely different sites in DNA from three different species are transcribed into RNAs even in cells which have not been transformed or infected by adenovirus. Some of these RNAs were cytoplasmic and were not poly(A)+. Human cell DNA sequences at the junction to Ad12 DNA in SYREC2 DNA were transcribed into poly(A)+ cytoplasmic RNA which could be translated in vitro. These results are consistent with the notion that at least some of the cellular DNA sequences at sites of insertion of adenovirus (foreign) DNA are transcriptionally active and thus provide an opportunity for recombination.

Serum angiotensin-I-converting enzyme and carboxypeptidase N in Crohn's disease and ulcerative colitis

Angiotensin-I-converting enzyme (ACE) and carboxypeptidase N1 and N2 (CPN1, CPN2) inactivate kinins and might therefore play a role in the development of inflammatory reactions via an influence on the release of prostaglandins and inactivation of anaphylatoxic peptides of the complement system. In the present study, the serum activity of these enzymes was determined in 60 patients with Crohn's disease, 18 patients with ulcerative colitis and 70 healthy control subjects. ACE was significantly lowered in active Crohn's disease (CDAI greater than 150) and in ulcerative colitis (p less than 0.01), as long as the ileum or cecum was affected. Since ACE was detected in high concentrations in the human intestinal mucosa, decreased values may be explained by damage to the site of its production. CPN1 and CPN2 were raised in both diseases (p less than 0.005), irrespective of their activity and location. These alterations in the activity of the kininases investigated may play a role in the pathogenesis of inflammatory bowel diseases.

Degradation of substance P by neurones and glial cells

Neuronal and astroblast-rich cultures from rat brain degrade exogenously added substance P. The rate of degradation is decreased by diisopropylfluorophosphate, phosphoramidon and bacitracin, but not by N-ethylmaleimide or bestatin. When diisopropylfluorophosphate, phosphoramidon and bacitracin are simultaneously present in the culture medium, the degradation of substance P is completely inhibited. These results indicate that the hydrolysis of substance P by intact cells is catalyzed by the post-proline dipeptidylaminopeptidase (EC 3.4.14.5), the thermolysin-like metallopeptidase ("enkephalinase", EC 3.4.24.11) and a yet uncharacterized bacitracin-sensitive activity. While the thermolysin-like metallopeptidase is mainly associated with glial cells, the specific activity of the other enzymes is five times higher in the neuronal culture.

Low molecular weight RNAs with homologies to cellular DNA at sites of adenovirus DNA insertion in hamster or mouse cells

The adenovirus type 2 (Ad2)-transformed hamster cell line HE5 contains one or very few integrated copies of Ad2 DNA. At the site of insertion of Ad2 DNA, the cellular DNA sequence has been completely preserved and has homologies to small unpolyadenylated, cytoplasmic RNAs of 300 nucleotides in length and to minority populations of smaller RNAs present in HE5 cells and in normal hamster cells. The 300-nucleotide RNA is present on average in approximately 20 copies per cell. This RNA, and shorter RNAs, reveal homologies to the hamster DNA sequence of approximately 400 nucleotides to the right of the site of insertion of Ad2 DNA, which is present in one or very few copies per genome. The nucleotide sequence of the DNA segment homologous to this RNA does not contain open reading frames in excess of a sequence encoding 18 amino acids. Thus, it is unlikely that the small RNAs are actually translated and their function is unknown. The nucleotide sequence does not exhibit similarities to known low mol. wt. RNAs of eukaryotic origin. The low mol. wt. cellular RNA has been found in HE5 cells, in other hamster cell lines and organs, and also in mouse cells. There are differences with respect to size and abundance in the RNAs smaller than 300 nucleotides between HE5 cells and LSH hamster embryo cells. The adenovirus type 12 (Ad12)-induced mouse tumor CBA-12-1-T carries greater than 30 copies of integrated Ad12 DNA. The cellular DNA sequence at the site of Ad12 DNA insertion exhibits homologies to small RNAs (approximately 300 nucleotides long) from mouse cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell electrophoretic characterization of lymphoid cells from various sources in patients with malignant non-Hodgkin lymphomas

Lymphocytes of 36 patients with malignant Non-Hodgkin lymphomas (NHL) were characterized by electrophoretic mobility (EPM) and EAC-rosette and E-rosette formation. Unimodal cytopherograms found in patients with low-grade malignant NHL are compatible with a monoclonal origin of the proliferating lymphoid cells. Within the CLL subgroup, deviations from the general mean EPM value in the intermediumrange were not unequivocally related to the B- or T-cell origin of the lymphocytes and remain to be explained. Comparing distinct entities of low-grade malignant NHL characterized by lymphocyte arrest at a certain stage of differentiation (Kiel Classification) we found an increase of the mean EPM in the direction of CLL----lymphoplasmacytoid immunocytoma----polymorphic immunocytoma. This arrest of leukemic cells at a certain EPM level may support a cytogenetically oriented subclassification of NHL. The Limitations of the diagnostic value of cytopherograms and rosette formation in malignant NHL--especially in those of high malignancy--are outlined.

Deletion of cellular DNA at site of viral DNA insertion in the adenovirus type 12-induced mouse tumor CBA-12-1-T

The adenovirus type 12 (Ad12)-induced mouse tumor CBA-12-1-T contains greater than 30 copies of viral DNA integrated into cellular DNA. One of the sites of linkage between the left terminus of Ad12 DNA and mouse DNA was cloned, mapped and sequenced by using conventional techniques. The preinsertion sequence was also cloned from normal CBA/J mouse DNA and sequenced. The sequence data and blotting analyses demonstrated that at the site of linkage nine nucleotide pairs of viral DNA and at least 1500 to 1600 nucleotide pairs of cellular DNA were deleted. Up to the site of linkage, the cellular DNA sequence in CBA-12-1-T tumor DNA and the preinsertion sequence in CBA/J mouse cells were identical. The site of Ad12 DNA integration was found to be located close to a site of transition from unique to repetitive cellular DNA sequences. The nucleotide sequence at the site of linkage and at the preinsertion site revealed palindromic stretches of 5 and 10 nucleotides pairs, respectively. Scattered patch homologies (8-10 nucleotide pairs long) were observed between adenoviral and cellular DNAs. A hypothetical model for DNA arrangements at the site of recombination is presented.

Muscular calcification following injection of vitamin E in newborn infants

Three newborn infants are presented in this case report who developed severe calcifications in the thighs after intramuscular injections of vitamin E. The prognosis seems to be good. Calcifications disappeared without clinical residue.

The adenovirus type 12 - mouse cell system: permissivity and analysis of integration patterns of viral DNA in tumor cells

The integration patterns of persisting adenovirus type 12 (Ad12) DNA were analyzed in two Ad12-induced tumors of Balb/c and CBA/J mice and in one tumor cell line derived from an Ad12-induced retinoblastoma of C3H origin. In all three tumors the Ad12 genome was integrated colinearly and various copy numbers of viral DNA were found. Analysis of the Ad12 integration patterns revealed relatively simple offsize band patterns regardless of Ad12 copy numbers. The degree of methylation at the 5'-CCGG-3' sites in the inserted Ad12 genome was determined using the isoschizomeric restriction endonuclease pair HpaII and MspI. Methylation was rather incomplete in the primary tumor tissues but almost complete in the retinoblastoma line carried in culture for many passages. The levels of expression of the viral genome in the Balb/c tumor and in the retinoblastoma line were determined by in vitro translation of RNA isolated from these cells and selected with appropriate restriction endonuclease fragments of Ad12 DNA. In both instances the 59 K, 19 K, and 17 K proteins of the E1b region were expressed. Proteins of the E1a region appeared very faint in the size class between 22 K and 42 K. The permissivity of Ad12 and the replication of Ad12 DNA in mouse cells were investigated by blotting restricted DNA from cells soon after, and a long time after, infection and by hybridization with 32P-labeled Ad12 DNA. Neither primary mouse kidney cells nor the established L929 mouse cell line supported viral DNA replication. These results raise the question to what extent host cell factors determine Ad12 DNA replication in mammalian cells.

[The synthesis, analysis, stability and biotransformation of N-(3-methylphenyl)-N'-cyanobenzamidine and analogues (author's transl)]

The antivirally active N-(3-methylphenyl)-N'-cyanobenzamidine (1) and some of its analogues were synthetized by the reaction of the ethyl ester of N-cyanobenzimidic acid with the corresponding arylamines. The analytical profile of 1 and of some of its analogues, which is needed for stability and biotransformation studies, was established by means of the following techniques: solubility determination, TLC, UV, IR and MS. When 1 is heated with methanolic HCl and NaOH (0.5 mol/l) for 1 h, several hydrolysis products are formed: m-toluidine, benzoic acid, benzoic acid 3-toluidide, N-(3-methylphenyl)benzamidine, N-(3-methylphenyl)-N'-carboxamidobenzamidine, benzoylurea, However, 1 is fairly stable under physiological conditions so biotransformation studies are not affected. After oral application of 1 to rats, the 3-hydroxymethyl and the 3-methyl-5-hydroxy compound as well as its glucuronide and sulphate conjugate were detected in the urine. The faeces contained considerable amounts of unchanged 1 (incomplete absorption).

[Dr. John Rittmeister - neurologist and resistance fighter]

He was born in Hamburg on 21st August 1898 and beheaded in the Plötzensee penitentiary on 13th May 1943. Our colleague was a personality combining professional striving and political commitment into a dialectic unity. The more important biographic data are given, the co-operation in the Schulze-Boysen-Harnack organisation is described as far as it has become known, and Rittmeister's scientific works are mentioned.