[Use of vindesine in lymphangitic-type cutaneous recurrence of breast cancer].
Explore the source record for details and available documents.
Antigens, Neoplasm↗
Biomedical subjects
E Giralt
Publications and source records attributed to E Giralt.
[Obstetrical behaviour in diabetes. Perinatal mortality (author's transl)].
Ever today diabetes and pregnancy constitute a high risk situation of the mother as well for the fetus, since still high maternal-fetal mortality rates are observed. A series of 134 diabetic women (99 type A, 15 type B, and 20 type C) were evaluated during pregnancy and delivery, and the results obtained during two different periods of time (1972-1975 and 1976-1978) are analyzed. From the results obtained the reduction of the indexes of perinatal mortality (before and after birth) stands out. These facts could probably be related to a change in the protocol applied during the last years and consisting in the administration of a carbohydrate supplement at night in order to avoid nocturnal hypoglycemias, admission of patients after the 32nd-34th week of pregnancy, complete rest in bed, control of the maturity of the fetus, etc. Likewise, there was a lack of significant rise in the presence of macrosomias, premature births, or urinary infection in the mother. As it was to be expected, the incidence of hydramnios as well as toxemia was higher than normal. The evaluation of the newborns through the Apgar score proved that 20 percent of the neonates in the type C diabetes were still partially or seriously depressed after 5 minutes of birth. A protocol of assistance in this special situation affords an evident reduction in perinatal mortality.
Apgar Score↗
A betamimetic drug and human fetal lung maturation.
In a double-blind and randomized study the administration of a betamimetic drug to the mother from week 33 to 35 produces a significant increase in amniotic fluid palmitic acid levels. We suggest that the administration of a betamimetic drug during pregnancy to the mother can be useful in producing an acceleration of the fetal lung maturation.
Adult↗
Influence of labour on the lecithin, lecithin/sphingomyelin (L/S) ratio and palmitic acid values in the amniotic fluid.
The lecithin/sphingomyelin (L/S) ratio, lecithin concentrations and palmitic acid levels in amniotic fluid were studied during labour and compared with values found before labour. All were significantly higher in women in labour. The explanation and significance of this finding are briefly discussed.
Amniotic Fluid↗
An attempt at blocking the cardiovascular and metabolic side-effects of beta-mimetic drugs during labor.
Explore the source record for details and available documents.
Blood Glucose↗
Native-like cyclic peptide models of a viral antigenic site: finding a balance between rigidity and flexibility.
Antigenic site A of foot-and-mouth disease virus (serotype C) has been reproduced by means of cyclic versions of peptide A15, YTASARGDLAHLTTT, corresponding to residues 136-150 of envelope protein VP1. A structural basis for the design of the cyclic peptides is provided by crystallographic data from complexes between the Fab fragments of anti-site A monoclonal antibodies and A15, in which the bound peptide is folded into a quasi-cyclic pattern. Head-to-tail cyclizations of A15 do not provide peptides of superior antigenicity. Internal disulfide cyclization, however, leads to analogs which are recognized as one to two orders of magnitude better than linear A15 in both ELISA and biosensor experiments. CD and NMR studies show that the best antigen, CTASARGDLAHLTT-Ahx-C (disulfide), is very insensitive to environment-induced conformational change, suggesting that cyclization helps to stabilize a bioactive-like structure.
Amino Acid Sequence↗
Structural comparison in solution of a native and retro peptide derived from the third helix of Staphylococcus aureus protein A, domain B: retro peptides, a useful tool for the discrimination of helix stabilization factors dependent on the peptide chain orientation.
A peptide fragment corresponding to the third helix of Staphylococcus Aureus protein A, domain B, was chosen to study the effect of the main-chain direction upon secondary structure formation and stability, applying the retro-enantio concept. For this purpose, two peptides consisting of the native (Ln) and reversed (Lr) sequences were synthesized and their conformational preferences analysed by CD and NMR spectroscopy. A combination of CD and NMR data, such as molar ellipcitity. NOE connectivities, H alpha and NH chemical shifts, 3J alpha N coupling constants and amide temperature coefficients indicated the presence of nascent helices for both Ln and Lr in water, stabilized upon addition of the fluorinated solvents TFE and HFIP. Helix formation and stabilization appeared to be very similar in both normal and retro peptides, despite the unfavourable charge-macrodipole interactions and bad N-capping in the retro peptide. Thus, these helix stabilization factors are not a secondary structure as determined for this specific peptide. In general, the synthesis and confirmational analysis of peptide pairs with opposite main-chain directions, normal and retro peptides, could be useful in the determination of secondary structure stabilization factors dependent on the direction.
Amino Acid Sequence↗
3D structure of kaliotoxin: is residue 34 a key for channel selectivity?
Kaliotoxin (KTX) is a natural peptide blocker of voltage-dependent K+ channels. The 3D structure of a truncated analogue of KTX (Fernandez et al. (1994) Biochemistry 33, 14256-14263) was determined by NMR spectroscopy and showed significant differences from structures established for other related scorpion toxins. A recent publication with the structure of the complete toxin (Aiyar et al. (1995) Neuron 15, 1169-1181) did not confirm these differences. In this communication we report NMR data for KTX at pH 3.0, 5.5 and 7.2 and the 3D structure obtained from data at pH = 5.5. Complete KTX displays a folding similar to that of other toxins with an alpha-helix and a beta-sheet linked by two disulphide bonds. The pKa of His 34 is anomalously low (4.7-5.2 depending on the buffer) owing to its interaction with two Lys residues (including the essential Lys 27), the charged N-terminus and the side chain of Met 29. Charged residues are placed symmetrically with respect to an axis that approximately coincides with one of the principal components of the moment of inertia of the toxin. His 34, which occupies a well-defined position between two conserved Cys, is located on the centre of a layer of charged groups. Positively and negatively charged residues are found at the same position in related toxins. It is suggested that electrostatic effects modulate the distances between positive charges in flexible side chains, contributing to the fine tuning of the selectivity toward different channel subclasses and that the approximate coincidence between the moment of inertia and the charge axis facilitate the approach of the toxin to the channel. The very low pKa of His 34 implies that it will be completely unprotonated at physiological pH.
Hydrogen Bonding↗
Solution versus solid-phase cyclization strategies for large sidechain lactam-bridged peptides: a comparative study.
A 22-residue peptide with a sidechain lactam bridge involving 18 residues (60-atom cycle) has been synthesized. Three different protection schemes using Fmoc/tBu/cyclohexyl, Fmoc/tBu/allyl or Boc/Bzl/ fluorenylmethyl protecting group combinations have been explored for the solid phase of the linear precursors, which have been subsequently cyclized in solution or in the solid phase. Cyclization yields in solution have been consistently better than on solid phase; however, the solid-phase strategy requires fewer purification steps and therefore global yields are comparable.
Amino Acid Sequence↗
Synthetic peptides as functional mimics of a viral discontinuous antigenic site.
Functional reproduction of discontinuous antigenic site D of foot-and-mouth disease virus (FMDV) has been achieved by means of synthetic peptide constructions that integrate into a single molecule each of the three protein loops that define the antigenic site. The site D mimics are designed on the basis of the X-ray structure of FMDV type C-S8c1 with the aid of molecular dynamics, so that the five residues assumed to be involved in antigenic recognition are located on the same face of the molecule, exposed to solvent and defining a set of native-like distances and angles. The designed site D mimics are disulphide-linked heterodimers that consist of a larger unit containing VP2(71-84), followed by a polyproline module and by VP3(52-62), and a smaller unit corresponding to VP1(188-194). Guinea pig antisera to the peptides recognize the viral particle and compete with site D-specific monoclonal antibodies, while inoculation with a simple (non-covalently bound) admixture of the three VP1-VP3 sequences yields no detectable virus-specific serum conversion. Similar results have been reproduced in two cattle. Antisera to the peptides are also moderately neutralizing of FMDV in cell culture and partially protective of guinea pigs against challenge with the virus. These results demonstrate functional mimicry of the discontinuous site D by the peptides, which are therefore obvious candidates for a multicomponent peptide-based vaccine against FMDV.
Amino Acid Sequence↗
Convergent solid-phase peptide synthesis IX: application to the synthesis of peptides with repetitive sequences.
The synthesis of a 36 amino acid peptide containing six conserved repeats of Val-His-Leu-Pro-Pro-Pro which corresponds to the glutelin-2 protein of maize has been carried out using a convergent approach. The protected single sequence repeat has been synthesized using a combination of a 9-fluorenylmethyloxycarbonyl (Fmoc) protection scheme and a p-alkoxybenzyl resin. The final peptide, as well as the different intermediate peptides, has been characterized by fast atom bombardment mass spectrometry (FAB-MS) and by co-elution with another sample obtained by stepwise continuous flow synthesis.
Amino Acid Sequence↗
Peptide ionophores: synthesis and cation-binding properties of a bicyclic peptide containing glycine and lysine residues.
Peptide 1, cyclo(1,5-epsilon-succinoyl) (Lys-Gly-Gly-Gly)2, is a representative member of a family of polycyclic peptide ionophores characterized by C2 symmetry and a relatively flexible structure resulting from its high Gly content. Peptide 1 has been synthesized by two different solid-phase protocols from its linear precursors, H-Gly-Gly-Lys(Fmoc)-Gly-Gly-Gly-Lys(Fmoc)-Gly-OH and H-Gly-Gly-Lys(Z)-Gly-Gly-Gly-Lys(Z)-Gly-OH), and satisfactorily characterized by chemical means. The CD spectrum of 1 is compatible with a beta-folded structure, stabilized by two internal hydrogen bonds. The complexation behavior of 1 toward alkaline and alkaline-earth cations can be envisaged as an equilibrium between inclusion (1:1) and sandwich (2:1) complex models, with affinities in the 10(6) M-1 and 10(11) M-2 range, respectively. A slight preference of 1 for Sr2+ over other cations has been found.
Amino Acid Sequence↗