In the idiotypic cascade initiated by the random terpolymer (Glu60Ala30Tyr10)n or "GAT", we have identified, in the D region of Ab2 antibodies, either Glu-Glu-Tyr or Tyr-Tyr-Glu sequences which mimic GAT immunodominant epitopes, thus suggesting a structural basis for the internal image. Peptides containing the two D-region characteristic sequences were then synthesized and coupled to BSA. In mice, they elicited antibodies, a fraction of which recognized GAT. These observations speak in favour of the localization of an internal image of the GAT antigen in the D region of Ab2 antibodies.

Amino Acid Sequence↗

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Molecular interactions in the "GAT" idiotypic network: an approach using synthetic peptides.

In order to approach some of the dominant epitopes which are recognized in the GAT (Glu60 Ala30Tyr10)n random terpolymer, a variety of peptides containing 7 to 14 residues were synthesized using glutamic acid and tyrosine as building blocks, and thus were able to mimic determinants common to GAT and GT (Glu50Tyr50)n. One decapeptide and on dodecapeptide were found to inhibit GT-mAb1 (or mAb1') binding to the same extent as GAT. Antibodies were also raised against synthetic peptides which reproduced the sequence of the 6 CDR of the germline anti-GAT Ab1 antibody. Antibodies were obtained against all peptides except L1, and were shown to recognize the native Ab1-Fab. Surprisingly, some of these antibodies also recognized GAT, i.e. anti-L2, anti-H2 and anti-H3, an observation which speaks in favour of a triggering of the idiotypic network at the Ab3 level. Finally, a monoclonal antibody derived from an immunization with an Ab2-D region synthetic peptide was found to be of the Ag+Id- type. Sequence data indicate that the light chain at least is completely different from that the of Ab1/Ab1', which uses only a very precise pair of V germline genes.

Animals↗

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Is there a germ-line network? The "GAT" case.

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Animals↗

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[Reflections on ureterocystomeostomy using a tubular vesical flap].

Authors cite 25 uretero-noecystostomy cases, carried out with the Boari flap technique, as well as their respective results several time after the operation. Authors underline both advantages and disadvantages, of presently most followed technics, i.e. Boari-Küss and Boari-Gil Vernet; furthermore, their experience suggests that vesico-ureteral reflux has never caused injuries to the upper urinary tract; the event a surgeon should be particularly afraid of, is stenosis of the uretero-vesical anastomosis. In order to have an easier anastomosis in case of dilated ureters, they also propose the Boari-Küss technique. while for normal-caliber ureters Boari-Gil Vernet technic is suggested.

Humans↗

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Methods of analysis for anthocyanins in plants and biological fluids.

Anthocyanins are the largest group of water-soluble pigments in the plant kingdom. They are responsible for most of the red, blue, and purple colors of fruits, vegetables, flowers, and other plant tissues or products. The analysis of anthocyanins is complex as a result of their ability to undergo structural transformations and complexation reactions. In addition, they are difficult to measure independently of other flavonoids, as they have similar structural and reactivity characteristics. Anthocyanins are generally extracted with weakly acidified alcohol-based solvents, followed by concentration (under vacuum), and purification of the pigments. Paper and/or thin-layer chromatography and UV-Vis spectroscopy have traditionally been used for the identification of anthocyanins. Capillary zone electrophoresis, a hybrid of chromatography and electrophoresis, is gaining popularity for the analysis of anthocyanins; however, liquid chromatography (LC) has become the standard method for identification and separation in most laboratories and may be used for both preparative and quantitative analysis. LC with mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy are possibly the most powerful methods for the structural elucidation of anthocyanins available, to date. At present, the most satisfactory method for mixture analysis is the multistep method of separation, isolation, and quantification by LC with peak identification by MS and high-field NMR.

Animals↗

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[Guidelines for dialysis. Replacement therapy for acute renal failure in critically ill patients].

Acute renal failure (ARF) in patients admitted to the intensive care unit (ICU) is mostly caused by ischemic or toxic injury, with a higher incidence in the latest years due to the growing number of interventions in cardiac and vascular surgery and to the general enhancement of reanimation techniques, which allow a better outcome among ICU patients. In critically ill patients, the ARF incidence reported in the literature ranges between 1 and 25%. Among ICU patients with ARF the mortality is between 40 and 65%, much more than in patients without this complication. Higher mortality rates, longer hospitalisation times and higher therapy costs demand from us an early diagnosis and treatment of ARF. Due to the lack of controlled and randomized proofs, recommended criteria for starting renal replacement therapy (RRT) in critical ARF patients might overlap with those for ESRD therapy. Moreover, randomised and controlled trials, confirming the actual efficacy of early onset of RRT on the mortality rate, are not yet available. As for stable ESRD patients, a direct relationship between dialytic doses and mortality and morbidity has been established for ARF patients. For ARF patients, as well as for ESRD patients, a minimum Kt/V of 1.2 three times a week should be ensured, although higher doses for critical ARF patients may achieve better results. The choice between intermittent (IRRT) and continuous renal replacement therapy (CRRT) in these patients is still a controversial issue. In spite of the fact that most studies report a better outcome in patients treated with CRRT, a recent meta-analysis failed to demonstrate any difference on the relative risk (RR) of mortality and on the rate of renal recovery between patients treated with either IRRT or CRRT. Furthermore, the use of peritoneal dialysis for the treatment of ARF patients in ICU has not been dismissed yet; so far this is indeed considered to be the technique of choice in some specific clinical situations. The intrinsic urgency of dialysis in ARF patients entails the use of temporary central venous catheters. The internal right jugular vein is usually preferred for these catheters because of the easier insertion and the lower risk of stenosis and thrombosis. The anticoagulant procedure should be chosen on the basis of patient characteristics, treatment typology and the likelihood of effectively monitoring its action. The choice of buffers in the dialysate, mostly lactate or bicarbonate, should depend on patient characteristics; so far, however, controlled but not randomized studies do not show any significant difference in the correction of metabolic acidosis between lactate and bicarbonate.

Acute Kidney Injury↗

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