[Selective abortion under sonographic control in multiple pregnancy]

Selective embryocide was performed at 9 weeks in a patient with a quadruplet pregnancy. No complications occurred and the patient was delivered of healthy triplets at 31 3/7 weeks of pregnancy. This procedure may be offered to patients with pregnancies with more than four embryos.

Characterization of interleukin-1 activity in tunicates

1. Eight North American species of tunicates were examined for the presence of interleukin-1 (IL-1) like activity. 2. The tunicates studied produce molecules with readily detectable lymphocyte activation factor (LAF) activity. 3. G50 column chromatography separated molecular species that were directly mitogenic for thymocytes (mol. wt greater than 50,000) from those that were comitogenic in an IL-1 assay (mol. wt 20,000). 4. Tunicate fractions with LAF activity induced increased vascular permeability in rabbit skin. 5. Tunicate LAF activity was neutralized by polyclonal anti-human IL-1 antisera. 6. These data further support the conclusion that IL-1 is an ancient and functionally conserved molecule.

Interrelationship between RU38486 and the P450 activities in rat liver

Microsomal P450 monooxygenases contribute actively to the biotransformation of the antiglucocorticoid RU38486, an 11 beta-substituted nor-steroid. Pretreatment of adult rats by inducers of specific forms, belonging to different P450 subfamilies, affects the ability of liver microsomes to metabolize RU38486. Phenobarbital and pregnenolone 16 alpha-carbonitrile increase the metabolic activity of liver microsomes whereas methylcholanthrene decreases their capacity to oxidize the steroid. Thus P450 forms IIIA, IIB1,2 and IIC7 are good candidates to be involved in the degradation of this peculiar molecule. Our study has been completed by investigating whether RU38486 would influence the P450 spectrum. Whereas the treatment of rats with either a glucocorticoid (cortisol, dexamethasone) or an antiglucocorticoid (pregnenolone 16 alpha-carbonitrile) has been shown to induce the P450 activity by increasing the hepatic concentration of form IIIA, we observed a slight decrease of the P450 activity by treating the animals with RU38486. Moreover RU38486 was able to antagonize the P450 induction by the other steroids as well as it inhibits the synthesis of various liver enzymes induced by glucocorticoids (for instance tyrosine aminotransferase). These findings may be important for the therapeutic use of RU38486 since its inhibitory effect on P450 activity may be at the origin of drug interactions by modifying the endogenous hormonal status.

The frog palate mucosa as a model for studying bacterial adhesion to mucus-coated respiratory epithelium

Most of the methods proposed to quantify bacterial adherence to respiratory mucosa differ mainly from in vivo conditions in the absence of the mucus blanket and in the exposure of the sub-mucosal connective tissue (SMCT) to the micro-organisms. We propose the frog palate as a model to study bacterial adhesion to the respiratory mucosa, with a system which allows the mucus to be preserved and the bacterial adhesion to be quantified in a standardized mucosal area, where mucociliary transport is still active. In order to evaluate the role of respiratory mucus in bacteria-mucosa interaction, we compared the adhesion of radiolabelled pneumococci to 12 mucus-coated and 10 non-mucus-coated frog palate mucosae. The presence or absence of mucus was controlled by scanning electron microscopy (SEM). After a 10 min incubation period, the bacterial adhesion to mucus-coated palate mucosa was five times greater (P less than 0.01) than that to uncoated mucosa. By SEM, bacteria were never seen attached to ciliated cells but could be detected on small areas where mucus was not totally eliminated. Even after a 120 min contact of bacteria to uncoated mucosa, bacterial adhesion remained only half that to mucus-coated epithelium. In order to ascertain whether the exposure of the SMCT represented a means of attraction to bacteria, we incubated the frog palate mucosa face-down with radiolabelled Pseudomonas aeruginosa. As much as 44 per cent of added bacteria adhered to exposed SMCT and, by SEM, numerous micro-organisms were seen attached to connective tissue. In contrast, only a few bacteria were observed adhering to the mucosa, mainly to granules of mucus.

Binding studies of the antiglucocorticoid RU38486 in Daudi and Raji lymphoma cells

The activity of RU38486 has been studied in Burkitt's lymphoma cells which are Epstein-Barr virus (EBV) positive. The early antigens (EA) of the virus are induced by dexamethasone (DXM) in Daudi but not in Raji cells, whereas a growth factor (transforming growth factor-beta, TGF-beta) induces the EA in both cell lines. RU38486 blocks the EA induction obtained by DXM or by TGF-beta in either cell line. In order to understand the interaction of RU38486, we considered its binding to specific receptors. We first investigated the binding of the antagonist in whole cells at 22 degrees C. A number of specific binding sites higher for RU38486 than for DXM was found, suggesting that RU38486 may bind to the glucocorticoid receptor and also to other cellular structures which we called the antiglucocorticoid binding sites ("AGBS"). To support this hypothesis, competition experiments have been conducted between RU38486 and other steroid hormones (progesterone and testosterone) since it is known that RU38486 is also able to interact with their cognate receptors. Binding studies of RU38486 in vitro at 4 degrees C in the presence of cytosolic extracts from Daudi and Raji cells led to conclusions similar to those drawn from the whole cell experiments: more complexes were formed with RU38486 than with DXM. Finally, the steroid-receptor complexes were incubated with DNA-cellulose. Since the binding measured for RU38486 was higher than for DXM, we suspect that sites different from the classical glucocorticoid receptor sites are also able to interact with DNA. The blockage exerted by RU38486 on the EA induced by glucocorticoids or by non-steroidal molecules and the lack of responsiveness to glucocorticoids in Raji cells are discussed in the light of the present findings.

Effect of growth on surface charge and hydrophobicity of Staphylococcus aureus

Modifications in the surface charge and hydrophobicity of Staphylococcus aureus Oxford during growth were studied by analysing electrophoretic mobility and adherence to hydrocarbons (hexadecane), respectively. Bacterial concentration had no effect upon the measurements. Both surface charge and hydrophobicity varied during the exponential phase of growth (1 to 4 h): surface charge decreased significantly (p less than 0.001), while hydrophobicity increased (p less than 0.001). In the stationary phase (4 to 9 h), the surface charge increased significantly (p less than 0.001), whereas hydrophobicity showed no change. Cationized ferritin decreased the surface charge and had no effect on hydrophobicity. These results suggest that in S. aureus, different structures could be responsible for their surface charge and hydrophobic properties.

Inhibition of hepatoma cell growth by a steroid anti-hormone

The antiproliferative effect of the potent antiglucocorticoid and antiprogestin RU38486, an 11 beta-substituted nor-steroid, was investigated on the HTC cell line. Its action clearly visualized in absence of serum, is reversible. Dexamethasone does whereas progesterone does not protect the cells against the cytostatic effect. Thus, the latter rather depends on the antiglucocorticoid- and not on the antiprogestin-function of RU38486. Taking into account the antiproliferative action on HTC cells together with the antiglucocorticoid behaviour in hepatocytes and hepatomas, our results suggest that RU38486 might represent a potential drug for liver tumour therapy.

Role of leukotrienes in acute gastric lesions induced by ethanol, taurocholate, aspirin, platelet-activating factor and stress in rats

This study was designed to determine the role of leukotriene C4 (LTC4) in the formation of acute gastric lesions induced by 100% ethanol, acidified taurocholate (TC), acidified aspirin (ASA), platelet-activating factor (PAF), and water-immersion and restraint stress. Exogenous LTC4 alone administered in gradually increasing doses (5-20 micrograms/kg/hr) caused only mild hemorrhagic lesions in the gastric mucosa but when combined with 100% ethanol, acidified TC, acidified ASA, or stress, it increased significantly the mean lesion area and lesion number as compared to those produced by these ulcerogens alone. FPL 55712, a LTC4 antagonist, given orally (2.5-10 mg/kg) reduced dose-dependently the extent of gastric lesions in all experimental models used and completely prevented the deleterious effects of exogenous LTC4 on gastric mucosa. PAF augmented the mucosal lesions induced by 100% ethanol, and this was also reduced by the pretreatment with FPL 55712. FPL 55712-induced gastroprotection against various ulcerogens was reversed, in part, by indomethacin, indicating that it could be attributed not only to the LTC4 antagonism but also to increased biosynthesis of PGs. This study provides evidence that LTC4 is involved in the formation of acute gastric damage and the antagonism of LTC4 may protect the mucosa against various ulcerogens.

Effects of leukotriene C4 on pancreatic secretion and circulation in dogs

In the present study the effects of leukotriene C4 (LTC4) on exocrine pancreatic secretion and pancreatic blood flow were determined. LTC4 given intravenously in various doses ranging from 0.35 to 2.8 nmol.kg-1.h-1 in conscious dogs caused a dose-dependent inhibition of pancreatic HCO-3 and protein responses to exogenous hormones such as secretin, cholecystokinin octapeptide (CCK-8), and bombesin and to endogenous stimulants including meat feeding and duodenal perfusion with oleate. In tests with pancreatic secretion induced by secretin plus CCK, maximal inhibition by LTC4 occurred at a dose of 1.4 nmol.kg-1.h-1 and reached approximately 70% of the control value for HCO-3 output and 45% for protein output. In tests with separate secretin- or CCK-induced secretion, maximal inhibition occurred at a dose of 1.4 nmol.kg-1.h-1 and reached 38 and 66% of the control HCO-3 and protein secretion, respectively. The same dose of LTC4 reduced the postprandial HCO-3 secretion by approximately 80% and protein output by approximately 70%. After administration of indomethacin, the pancreatic secretion declined, but the inhibitory effects of LTC4 remained unchanged. Pancreatic tissue generated two to three times more LTC4 than the gastrointestinal mucosa, and indomethacin caused further increase in this generation, suggesting that LTC4 may contribute to indomethacin-induced pancreatic inhibition. (ABSTRACT TRUNCATED AT 250 WORDS)

Structural and immunochemical properties of rat liver tyrosine aminotransferase

Our results show for the first time sequence data of the N-terminal part of tyrosine aminotransferase. This unblocked form of TATase, which has never been detected before, starts with a serine. This serine was found at position 29 of the primary structure of the enzyme deduced from the cDNA. We suggest that this free N-terminal amino acid is the extremity of a TATase form generated by proteolysis during the process of purification. Thus, proteolysis does not occur at the C-terminal as has been suggested before, but rather at the N-terminal region of the enzyme. To confirm this possibility, a peptide corresponding to the sequence of the seven carboxy-terminal amino acids of TATase was synthesized. It was coupled to ovalbumin or keyhole limpet hemocyanin, and the resulting conjugates were used to raise anti-peptide antibodies. The crude sera obtained were purified and their abilities to recognize TATase in ELISA and dot-blot experiments were proven. Our results demonstrate that the C-terminal part of the enzyme is present and well-recognized by the anti-peptide serum prepared. Furthermore, the anti-peptide serum reacts with TATase without inhibiting its enzymatic activity.

Vasoactive and metabolic effects of leukotriene C4 and D4 in the intestine

The effects of intra-arterial administration of leukotrienes (LT) C4 and D4 upon total intestinal and mucosal blood flow, intestinal oxygen consumption and motor activity were measured in anesthetized dogs. Blood flow to a segment of distal ileum was measured with an electromagnetic blood flow meter, and arteriovenous oxygen difference (AVO2) was determined spectrophotometrically. Oxygen consumption was calculated as the product of AVO2 and total blood flow. Intestinal mucosal blood flow was determined by a local H2-gas clearance technique. Motor activity was monitored on the basis of changes in intraluminal pressure. LTC4 and LTD4 induced a dose-related decrease in total intestinal blood flow, mucosal blood flow and in oxygen consumption, and an increase in intestinal motor activity. Both LT produced a redistribution of blood flow into the muscular compartment of the intestinal circulation. The results of these studies indicate that LTC4 and LTD4 are potent vasoconstrictors in the intestinal microcirculation, and that endogenous LT may contribute to the microvascular changes leading to the intestinal damage.

Comparison of betaxolol with verapamil in hypertensive patients: discrepancy between office and ambulatory blood pressures

The purpose of this study was to compare in the individual hypertensive patient the blood pressure lowering effect of a beta-blocking agent i.e. betaxolol with that of a calcium entry blocker, i.e. verapamil. The antihypertensive efficacy of the drugs was evaluated both at the physician's office and by monitoring ambulatory daytime blood pressure using a portable blood pressure recorder (Remler M2000). Seventeen patients with uncomplicated essential hypertension (aged 35-67 years) were treated for two consecutive 6-week periods with either betaxolol, 20 mg/day or a slow-release formulation of verapamil, 240-480 mg/day. The sequence of treatment phases was randomly allocated and a 2-week wash-out period preceded each treatment. Both betaxolol and verapamil had a significant blood pressure lowering effect when assessed at the physician's office. However, ambulatory recorded blood pressures were significantly reduced only with betaxolol. In the presence of a physician, the best responders to betaxolol tended to be also the best responders to verapamil, whereas there was no relationship between the fall in ambulatory recorded blood pressure observed during betaxolol and the corresponding fall during verapamil administration. The blood pressure response to both betaxolol and verapamil was not related to age.

Antagonistic action of RU38486 on the activity of transforming growth factor-beta in fibroblasts and lymphoma cells

Transforming growth factor-beta (TGF-beta) is a multifunctional protein involved in the control of proliferation, differentiation and other functions in many cell types. The anchorage-independent growth of some established lines of untransformed fibroblasts in soft agar is induced by TGF-beta and requires in addition exogenous EGF for certain target cells, notably rat NRK-49 cells. The formation of colonies of NRK-49F cells is completely inhibited by the synthetic 11-beta substituted nor-steroid RU38486 added at a final concentration of 1.3 X 10(-5) M. We also explored the effect of TGF-beta on Daudi and Raji lymphoma cells by measuring the production of Epstein-Barr Virus (EBV) early antigens (EA). In Daudi cells an induction capacity giving rise to 10-16% positive EA-cells was observed; in Raji cells the induction only reached between 6 and 8%. The induction was partially inhibited by the anti-steroid RU38486 in both systems. Thus, RU38486 not only antagonizes the glucocorticoid hormone action but also interferes with the effects of TGF-beta in fibroblasts and in lymphoma cells. The molecular basis of the interactions observed was investigated by considering (1) the binding to specific receptors, (2) transfection experiments, in order to examine if the interference of the anti-steroid with TGF-beta activities occurs at the transcriptional level as in the case of glucocorticoid induction. The results suggest that the blocking by antiglucocorticoids of the effects of TGF-beta and glucocorticoids, in fibroblasts and lymphoma cells, occurs by different mechanisms.

Factors interfering with the 1 mg dexamethasone suppression test in depression

The 1 mg dexamethasone suppression test (DST) was performed in 50 depressive inpatients in order to investigate factors which might interfere with its sensitivity and specificity for endogenous depression: improvement within one week after the test, recent admission to a psychiatric ward, and weight loss. Four out of five endogenous depressive patients whose depression improved within one week after the test had normal suppression, thus supporting the assumption that normalization of the DST may precede the improvement in depression. Nonendogenous depressive patients had an accumulation of pathologic test results on the day after admission that may be due to "admission stress". However, in endogenous depressives this effect was not observed. An influence of weight loss on the percentage of suppressors and nonsuppressors was not demonstrable. It is concluded that in the evaluation of DST results time parameters should be considered to a greater degree.

Effect of human airway lysozyme on the in vitro growth of type I Streptococcus pneumoniae

The effects of purified human airway lysozyme and hen egg-white lysozyme on growth rate and viability of growing type I Streptococcus pneumoniae were studied. Exposure of bacteria to human and hen lysozyme at the same final concentration (100 micrograms/ml) for 1.5-4.5 h resulted in a marked reduction of the number of colony-forming units per ml compared to control cultures. After a 1.5-h exposure to human or hen lysozyme, the remaining percentage of colony forming units per ml was 54% and 69%, respectively. The onset of growth only appeared after a 3.5-h exposure period for human lysozyme whereas it began at 2.5 h for hen lysozyme. After 3.5 h and 4.5 h of exposure, the number of colony-forming units was significantly lower (p less than 0.05) in human lysozyme-treated bacteria cultures compared to control cultures. Parallel electron microscopic observations of Streptococcus pneumoniae cultures confirmed that the density of pneumococci was less in the presence of either human lysozyme or hen lysozyme in comparison to control cultures, and showed the presence of numerous long, ribbon-like material and cytoplasmic condensations liberated in the culture medium.

Cysteinyl leukotrienes as mediators of staphylococcal enterotoxin B in the monkey

The role of cysteinyl leukotrienes (LTs) in the action of staphylococcal enterotoxin B (SEB) was investigated in unsensitized monkeys using inhibitors of prostanoid synthesis and LT action and by measuring generation of LT in vivo. LY 171883, a selective LTD4/LTE4 receptor antagonist, proved highly efficient in inhibiting immediate-type hypersensitivity reactions in the skin and protecting against the emetic response provoked by SEB in a concentration-dependent manner. Inhibition of prostanoid formation by pretreatment of monkeys with indomethacin or aspirin did not influence SEB responses. Based on chromatographic and radioimmunologic analysis, the generation of endogenous cysteinyl LTs was demonstrated in vivo. The concentration of LTE4, the major biliary cysteinyl LT detected, increased ten-fold and a novel cysteinyl LT metabolite in urine indicated strongly enhanced LT generation upon challenge with SEB. Cysteinyl LTs are important mediators in the pathophysiology of SEB-induced enteric intoxication. Therefore, cysteinyl LT antagonists may be of therapeutic value in the treatment of this intestinal disorder.

[Treatment of aluminum-induced osteopathy with desferrioxamine in dialysis-dependent renal failure]

Presenting two patients on long-term dialysis with marked osteopathy due to aluminium intoxication we described the symptoms, pathogenesis and therapy of the disease. Two patients were treated with the chelating agent desferrioxamine which lead to a striking improvement in clinical symptoms and removal of aluminium from bone. Osteopathy due to aluminium intoxication is refractory to Vitamin D and its metabolites. Using reversed osmosis in dialysis the high aluminium levels in bone result mainly from the long-term use of phosphate binders. Therapy of choice is the treatment with desferrioxamine.