Field performance of sugarcane (Saccharum sp.) plants derived from cryopreserved calluses

This study compared the field performance of sugarcane plants originating from three different sources: control, non-cryopreserved embryogenic calluses, cryopreserved embryogenic calluses and macropropagated material of the same commercial hybrid. Several agronomic traits were evaluated on 100 plants per treatment over a 27-month period covering the growth of the stool and of the first ratoon. Significant differences between treatments were observed only during the first six months of field growth of sugarcane stools. Stems produced from in vitro cultured material, irrespective of their cryopreservation status, had a smaller diameter and a shorter height than those produced from macropropagated material. These differences disappeared by 12 months of stool field growth.

4-Hydroxybenzoate uptake in Klebsiella planticola strain DSZ1 is driven by DeltapH

Klebsiella planticola strain DSZ1 has the ability to degrade different aromatic compounds such as benzoate and organochlorinated as propachlor and alachlor. DSZ1 strain cells mineralised 4-hydroxybenzoate (4HBA) through a meta-cleavage pathway, yielding protocatechuate as dihydroxylated intermediate, with a specific rate of CO2 formation 0.12 x 10-6 (cpm/OD) h-1, and a rate of 4-HBA utilisation of 0.75 mmol h-1. Aerobically the 4HBA transport system is driven by gradient of protons (DeltapH), but is not ATP-driven. Under anaerobic conditions, the system can use the nitrate reduction as a final electron acceptor in respiration. A kinetic analysis of the 4HBA transport system revealed a Kt value of 16 microM with a Vmax value of 25 nmol/min.mg at pH 7.

Preparation of seven- and eight-membered boron heterocycles from different salen ligands and arylboronic acids

Arylboronic acids and different salen ligands have been brought to reaction in a 2:1 stoichiometry in ethanol, toluene, and acetonitrile. In all cases bimetallic boronates with chiral boron atoms could be isolated with the difference that in ethanol mostly open bimetallic boronic esters are obtained, while in toluene or acetonitrile closed bimetallic complexes with a central seven- or eight-membered heterocyclic ring are formed. Both structural types have been characterized by spectroscopic techniques and X-ray crystallography showing that the reactions are diastereoselective in the case of the bimetallic heterocyclic structures. The configurations and conformations of the seven- and eight-membered rings are different, and this may depend on steric effects and/or repulsive intramolecular pi-pi interactions between the two salicylidene moieties attached to the central ring.

Diversity among clinical isolates of penicillin-resistant Streptococcus mitis: indication for a PBP1-dependent way to reach high levels of penicillin resistance

A total of 12 non-epidemiologically related clinical isolates of Streptococcus mitis that showed different levels of resistance to penicillin were studied. Membrane-protein profiles and penicillin-binding protein (PBP) patterns showed a great polymorphism; and patterns of 4-7 PBPs, with sizes that ranged from approximately 101 kDa to approximately 40 kDa, were detected in each strain. No association could be found between PBP pattern and resistance level to penicillin among these isolates. Arbitrarily primed PCR confirmed the genetic diversity among this group of streptococci. One of the isolates of intermediate level of resistance to penicillin, which showed a PBP pattern similar to that of the high-resistance strains, was used as a laboratory model to analyse the mechanism underlying high-resistance acquisition by these strains. A 14-fold increase in penicillin resistance was obtained after a single selection step, which resulted in a decrease in penicillin affinity for PBP1. The size of this PBP (92 kDa) and the differences in PBP profiles of the penicillin-resistant clinical isolates suggest the existence in S. mitis of PBP-mediated mechanisms to acquire high-level resistance to penicillin, among which alterations in PBP1 seem to play a main role, in contrast to the PBP2X mediated mechanism described for other streptococci.

The response in old mice: positive and negative immune memory after priming in early age

To analyze the effect of age in both B and T cell compartments of the immune system, we have studied the anti-dextran (Dx) B512 humoral immune response in aged C57BL/6 mice. We have used Dx in its native form, which induces a thymus-independent (TI) response, or conjugated to chicken serum albumin (CSA), which induces a thymus-dependent (TD) response. We have also analyzed the adjuvant effect of cholera toxin (CT) in both types of responses. Our results show that the B cell compartment is not greatly affected by age as demonstrated in the TI responses and that CT is a powerful adjuvant despite the age of the animals. However, we found a severe age-associated impairment of TD responses. We conclude that the first antigenic challenge deeply influences further antigenic responses in a positive or negative manner. Priming in early life with native Dx (TI) inhibited late TD responses in aged mice, even when the primary immunization had occurred a long time ago. This negative memory affects posterior TD responses both in the quantity and in the affinity of the response. However, immunization at an early age with TD priming (CSA-Dx) provoked a long-lasting immune memory that abolished in part the age-associated impairment of the response. Our results suggest that protocols of vaccination with TI antigens may not be a convenient strategy, because the development of further optimal immune responses to the same antigen can be impaired.

Identification of Staphylococcus spp. by PCR-restriction fragment length polymorphism of gap gene

Oligonucleotide primers specific for the Staphylococcus aureus gap gene were previously designed to identify 12 Staphylococcus spp. by PCR. In the present study, AluI digestion of PCR-generated products rendered distinctive restriction fragment length polymorphism patterns that allowed 24 Staphylococcus spp. to be identified with high specificity.

The sequence of a 15 769 bp segment of Pichia anomala identifies the SEC61 and FBP1 genes and five new open reading frames

We have determined the sequence of a 15 769 bp DNA segment of Pichia anomala. The sequence contains seven complete open reading frames (ORFs) longer than 100 amino acids and a putative tRNA gene. Two of the ORFs code for the well-characterized genes SEC61 (which codes for the core subunit of the ER translocation complex) and FBP1 (encoding fructose-1,6-bisphosphatase). A gene coding for a protein similar to S. cerevisiae YDL054c was found between the two genes. These three genes show a different organization (intermingled triples) in three yeast species: Saccharomyces cerevisiae, Candida albicans and P. anomala. Two out of the four remaining ORFs show weak homology with different proteins from other species and the other two show non-significant similarity with previously sequenced genes. The nucleotide sequence has been submitted to the EMBL database under Accession No. AJ306295.

Analysis of 41 kb of the DNA sequence from the right arm of chromosome II of Schizosaccharomyces pombe

We report the complete sequence of cosmid c18A7 (41 046 bp insert), located on the right arm of chromosome II of the Schizosaccharomyces pombe genome. The sequence, which partially overlaps with cosmids SPBC4F6 and SPBC336, contains 16 open reading frames (ORFs) capable of coding for proteins of at least 100 amino acid residues in length (one partial) and one small nucleolar RNA (snoRNA). Four known genes were found: swi10 (encoding a mating-type switching protein also involved in nucleotide excision repair); dim1 (encoding a dimethyladenosine transferase); arf1 (encoding ADP-ribosylation factor 1); and pol3 (cdc6) the partial fragment, encoding the 125 kDa catalytic subunit of the DNA polymerase type B. Six ORFs similar to known proteins were found. They include a transporter of the major facilitator superfamily class, a vacuolar sorting protein, an asparagine synthase, a nuclear protein, a reticulum oxidoreductin and a heat shock protein. Each protein product of the other six ORFs has conserved domains and can be assigned a molecular, but not a biological, function. The sequence has been submitted to the EMBL database under Accession No. AL080287.

Certification of the mass concentration of creatine kinase isoenzyme 2 (CK-MB) in the reference material BCR 608

We describe the certification of a mass concentration value in the already prepared creatine kinase-2 reference material (BCR 608). Creatine kinase-2 was purified from human heart. The purified enzyme was diluted in order to measure its protein concentration by the Doetsch method. A protein concentration value of 124.30+/-13.17 mg/l was assigned to the stock solution of purified creatine kinase-2. This stock solution was diluted in 25 mmol/l piperazine-N,N'-bis[2-ethanesulfonic acid] (PIPES) pH 7.2, containing 2 mmol/l ADP, 5 mmol/l 2-mercaptoethanol, 154 mmol/l sodium chloride and 50 g/l human albumin to obtain a stable liquid standard of known creatine kinase-2 mass concentration (80.36 microg/l). This standard was then used to recalculate the creatine kinase-2 mass concentration measured in the BCR 608 material by immunoassay. The mass concentration of creatine kinase-2 in samples of reconstituted BCR 608 was certified to be 93.30+/-9.65 microg/l.

Antimicrobial activity of three Mexican Gnaphalium species

The antibacterial activity of the hexane, ethyl acetate and methanol extracts of the flowers, leaves and stems of Gnaphalium oxyphyllum var. oxyphyllum, G. liebmannii var. monticola and G. viscosum was investigated. The hexane extracts showed in all cases the higher inhibitions, G. oxyphyllum flower extract exhibiting the wider spectrum of activity.

Gene order in a 10 275 bp fragment of Yarrowia lipolytica, including adjacent YlURA5 and YlSEC65 genes conserved in four yeast species

We have determined the sequence of a 10275 bp DNA segment of Yarrowia lipolytica located on chromosome VI. The sequence contains six complete open reading frames (ORFs) longer than 100 amino acids and two more partial ORFs at both ends. Two of the ORFs encode for the well-characterized genes YlURA5 (orotate phosphoribosyltransferase) and YlSEC65 (encoding a subunit of the signal recognition particle). These two genes show an identical organization-located on opposite strands and in opposite orientations-in four yeast species: Saccharomyces cerevisiae, Kluyveromyces lactis, Candida albicans and Y. lipolytica. One ORF and the two partial ORFs code for putative proteins showing significant homology with proteins from other organisms. YlVI-108w (partial) and YlVI-103w show 39% and 54% identity, respectively, with YDR430c and YHR088w from S. cerevisiae. YlVI-102c (partial) shows significant homology with a matrix protein, lustrin A from Haliotis rufescens, and with the PGRS subfamily (Gly-rich proteins) of Mycobacterium tuberculosis. The three remaining ORFs show weak or non-significant homology with previously sequenced genes. The nucleotide sequence has been submitted to the EMBL database under Accession No. AI006754.

A single-copy suppressor of the Saccharomyces cerevisae late-mitotic mutants cdc15 and dbf2 is encoded by the Candida albicans CDC14 gene

The Saccharomyces cerevisiae CDC15, DBF2, TEM1 and CDC14 genes encode regulatory proteins that play a crucial role in the latest stages of the M phase of the cell cycle. By complementation of a S. cerevisiae cdc15-lyt1 mutant with a Candida albicans centromeric-based genomic library, we have isolated a homologue of the protein phosphatase-encoding gene CDC14. The sequence analysis of the C. albicans CDC14 gene reveals a putative open reading frame of 1626 base pairs interrupted by an intron located close to the 5' region. Analysis of C. albicans cDNA proved that the intron is processed in vivo. The CaCDC14 gene shares 49% of amino acid sequence identity with the S. cerevisiae CDC14 gene, 46% with Schizosaccharomyces pombe homologue, 35% with Caenorhabditis elegans and 37% and 38% with human CDC14A and CDC14B genes, respectively. As expected, the C. albicans CDC14 gene complemented a S. cerevisiae cdc14-1 mutant. We found that this gene was able to efficiently suppress not only a S.cerevisiae cdc15-lyt1 mutant but also a dbf2-2 mutant in a low number of copies and allowed growth, although very slightly, of a tem1 deletant. Overexpression of the human CDC14A and CDC14B genes complemented, although very poorly, S. cerevisiae cdc15-lyt1 and dbf2-2 mutants, suggesting a conserved function of these genes throughout phylogeny. The sequence of CaCDC14 was deposited in the EMBL database under Accession No. AJ243449.

Increases in ornithine decarboxylase activity in the positive inotropism induced by androgens in isolated left atrium of the rat

It is well established that the intracellular receptors of androgens act as transcription factors upon their activation by androgen binding. However, a growing number of studies have associated androgens with rapid biological responses independent of their classical action mechanism. In this sense, 5alpha- and 5beta-dihydrotestosterone elicited a rapid positive inotropism in the isolated left atrium of the rat via cAMP-dependent mechanisms that may involve genomic effects. In addition, polyamines are mediators of several biological actions including those acute and long-term effects induced by androgens in the heart. The present study analyzed the role of polyamine synthesis in the cardiotonic effect of androgens in the left atrium of male Wistar rats, electrically stimulated (0.5 Hz, 5 ms and supramaximal voltage) and placed in an organ bath in 10 ml of Tyrode's solution. Incubation in the organ bath with an inhibitor of ornithine decarboxylase activity, alpha-difluoromethylornithine 10 mM, significantly decreased the positive inotropism induced by 5alpha- and 5beta-dihydrotestosterone (0.1-100 microM). This suggests that ornithine decarboxylase seems to be involved in androgen-induced positive inotropism. Furthermore, 6-min exposure to 5alpha- or 5beta-dihydrotestosterone significantly increased the activity of ornithine decarboxylase from 61.81+/-7.53 (control) to 93.28+/-9.45 and 80.28+/-12 pmol/h/mg of protein, respectively. Northern blot analysis showed that 5alpha- and 5beta-dihydrotestosterone did not modify the level of expression of the ornithine decarboxylase gene. Therefore, our results suggest that polyamine synthesis might be involved in the positive inotropism elicited by androgens through the stimulation of ornithine decarboxylase activity without changes in the expression of the ornithine decarboxylase gene.

[Liquid ecstasy poisoning: study of 22 cases]

BACKGROUND

To describe characteristics of acute poisoning with liquid ecstasy (gammahydroxybutyrate, GHB).

PATIENTS AND METHOD

Epidemiological and clinical data of patients with acute GHB poisoning seen at emergency department (ED) along one year were collected.

RESULTS

22 patients were included. Typical profile corresponds to a young male, who consults on weekend, at night, complaining of a marked decreased level of consciousness. Patients refer coingestion of other drugs and typically regain consciousness spontaneously in a short time.

CONCLUSION

The frequency of GHB poisoning has increased notably in our environment. GHB poisoning must be considered on the differential diagnostic of coma of unknown origin in young patients attended in ED.

[Impact in the quality of health care and cost-effectiveness analysis of the reform of an emergency medicine service]

BACKGROUND

To determine the effects that the reform of an emergency department (ED) have on efficacy, health care quality and efficiency.

MATERIAL AND METHOD

Reforms consisted of 50% and 34% increases in structural and human resources, respectively. Roles of each ED member were redetermined, new assistance pathways were implemented, and the relationship between ED and the remaining hospital departments was reassessed. As efficacy markers, we determined the number of patients waiting to be attended (Pesp), the waiting time of patients to receive medical assistance (T(esp)),and the total waiting time of patients staying in the ED (T(total)). As health-care quality markers, we determined the percentage of patients leaving ED without having been visited by a physician(IPNV), the percentage of patients who were visited again (IPR),and the percentage of mortality (IPF). We also quantified the number of visits to the ED. All these data were obtained daily over 3 weeks, before (February 1999) and after (February 2000)the reforms. Effectiveness was estimated from the ratio P(total)/T(esp)(E1) and P(total)/P(esp) (E2). Costs were recorded for both periods and a cost-effectiveness analysis was performed to study the efficiency.

RESULTS

In 2000, the number of visits increased by +12% (CI 95%: 2% to 22%). Despite this increase, we observed an improvement of most efficacy and health-care quality markers after the ED reforms. E1 increased by 996% (CI 95%: 335% to 1,658%) and E2 increased by 186% (CI 95%: -23%to 395%). Cost-effectiveness analysis showed 70% (CI 95%: 33%to 107%) and 56% (CI 95%: 18% to 94%) increases regarding E1 and E2, respectively, after the reforms.

CONCLUSIONS

Providing ED with the necessary resources leads to an objective improvement of its efficacy and health-care quality and, consequently, the service and quality perceived by users improve. Despite the total cost increase after the ED reforms, efficiency also improves.

Isolation of the fibrocrystalline body, a structure present in haloarchaeal species, from Halobacterium salinarum

An organized structure, the fibrocrystalline body (FB), has been isolated from the archaeon Halobacterium salinarum. The structure is also present in, and can be isolated from, other extreme halophilic archaea. FB is present in the cytoplasm during the exponential growth and early stationary phases. This structure is affected by vincristine, an antitumoral drug, which targets tubulin. The drug causes fragmentation of the FB, changes in the cell shape, and growth inhibition. Taken together, these results point toward an important role in the life of the cell for this highly organized structure.

Increased duodenal mucosa infiltration by mast cells in rats with portal hypertension

BACKGROUND

Enteropathy characterized by vascular and inflammatory alterations in the submucosa and mucosa has been described in patients with portal hypertension.

AIMS

To verify the theory of inflammatory etiopathogenesis in experimental portal hypertensive duodenopathy, a prehepatic portal hypertension model based on the development of a single and triple partial ligation of the portal vein was used in the rat.

METHODS

Five rats in each group (male Wistar, 230-255 g) were subjected to single (group II) or triple (group III) partial ligation of the portal vein and then compared to 5 control animals (group I, no operation). The animals were sacrificed 6 weeks later to analyze the histological parameters of the duodenal mucosa and submucosa, i.e., number, diameter and area of submucosal vessels, density of mast cells and mitotic cells. Body, liver and spleen weights and collateral circulation type were also assayed.

RESULTS

As was demonstrated by the collateral circulation in all of the animals, the partial portal ligation was successful. Compared to the controls, the number of vessels per microscopic field (25 +/- 3.16 vs. 18.60 +/- 1.52), their diameter (20.09 +/- 2.90 vs. 12.61 +/- 3.97 microm, p < 0.05) and consequently their total area (12,749.30 +/- 2,298.26 vs. 3,455.82 +/- 1,702.33 microm2) were increased in the animals with a single partial ligation (group II) as well as in animals receiving triple partial ligation (group III) (33 +/- 12.88, p < 0.05; 22.92 +/- 6.72 microm, p < 0.05 and 51,376.95 +/- 43,732.24 miccrom2, p < 0.05, respectively). In addition, the density of mast cells increased from 3.26 +/- 1.18 in controls to 10.74 +/- 1.47, p < 0.01 and 22.50 +/- 6.42, p < 0.01 in single and triple partial portal ligated animals, respectively. Mitosis was significantly induced in crypts of the duodenal mucosa of the single portal ligated animals (25.20 +/- 1.78 vs. 17.40 +/- 1.14, p < 0.01) but was inhibited in triple partial ligated animals (12.40 +/- 5.12, p < 0.05). Compared to controls, both groups of rats developed liver atrophy with a greater decrease in the liver/body weight ratio in the single (2.71 +/- 0.50%, p < 0.01) compared to the triple partial ligated animals (3.33 +/- 0.09%, p < 0.01).

CONCLUSIONS

The correlation of the degree of portal hypertension with the vascular changes and mast cell density suggests that both the hypertensive state and inflammation may play a role in the development of portal hypertensive intestinal vasculopathy. The inverse relation of portal hypertension with liver atrophy and mitosis rate in the crypts of the duodenal mucosa has not been clarified and should be investigated in future studies.

Effect of strict blood pressure control on proteinuria in renal patients treated with different antihypertensive drugs

BACKGROUND

The severity of proteinuria is the main predictive factor in the progression of renal failure in chronic nephropathies. Therefore, action aimed at reducing proteinuria should be a priority in the treatment of these patients. Various antihypertensive drugs, in particular the angiotensin-converting enzyme inhibitors (ACEIs), have a greater antiproteinuric effect, although it is difficult to establish whether this is due only to their effect on arterial blood pressure (BP) or to other mechanisms associated with blockade of the renin-angiotensin system (RAS).

METHODS

The evolution of proteinuria after two successive treatment periods was studied prospectively for 2 years in 22 patients with chronic glomerulonephritis. In period I, which lasted for 12 months, BP was strictly controlled (<125/75 mmHg) and the patients received random and double-blind treatment with a beta-blocker (betaB), atenolol; a non-dihydropyridine calcium channel blocker (CCB), verapamil; an ACEI, trandolapril; or a fixed combination of the latter two. In period II, all of the patients received treatment openly for an additional 12 months with a fixed combination of verapamil+trandolapril at half the dose of the preceding period, to obtain conventional control of BP at <140/90 mmHG:

RESULTS

The mean level for basal SBP/DBP was 136+/-14/86+/-7 mmHg, which decreased in period I to 121+/-15/76+/-8 mmHg (P=0.01) and to 124+/-5/78 +/-8 mmHg (P<0.05) at 6 and 12 months of treatment, respectively. There were no differences in the BP reached in the four therapy groups; however, proteinuria only decreased in the patients treated with trandolapril alone or in combination with verapamil. In period II, BP levels rose to 134+/-10/84+/-8 mmHg (P<0.05); this increase in BP was accompanied by an increase in proteinuria in those patients who had received the ACEI alone or in combination in the previous period, while in patients previously treated with a betaB or a CCB, proteinuria decreased, in spite of the increase in BP.

CONCLUSIONS

With equal BP control, treatment with the ACEI trandolapril alone, or in combination with a CCB, has a greater antiproteinuric effect than that obtained with other antihypertensive drugs, but this effect is attenuated if BP is not strictly controlled.

Virulence genes in the pathogenic yeast Candida albicans

In recent years, the incidence of fungal infections has been rising all over the world. Although the amount of research in the field of pathogenic fungi has also increased, there is still a need for the identification of reliable determinants of virulence. In this review, we focus on identified Candida albicans genes whose deletant strains have been tested in experimental virulence assays. We discuss the putative relationship of these genes to virulence and also outline the use of new different systems to examine the precise effect in virulence of different genes.

Analysis of the serologic response to systemic Candida albicans infection in a murine model

Two different strains of mice with different susceptibilities to systemic candidiasis (BALB/c and CBA/H) were infected with Candida albicans SC5314. Immune sera were obtained on different days post-infection and assayed against two-dimensional polyacrylamide gel electrophoresis separation of cytoplasmic extracts obtained from protoplasts. More than 31 immunoreactive proteins were detected. Some of them were identified and found to correspond to (i) glycolytic enzymes, such as fructose biphosphate aldolase, triose phosphate isomerase (TPIS), glyceraldehyde-3-phosphate dehydrogenase, 3-phosphoglycerate kinase (PGK), enolase (ENO1) and pyruvate kinase, (ii) other metabolic enzymes, such as methionine synthase (METE), inosine-5'-monophosphate dehydrogenase (IMH3), alcohol dehydrogenase and aconitate hydratase and (iii) heat shock proteins: HS71 (or Ssa1p) and HS75 (or Ssb1p), both from the HSP70 family. This work reports for the first time antigenic properties for IMH3 and TPIS. Different profiles of antibody expression, depending on the mouse strain and the course of infection, were observed. ENO1 was the most immunogenic protein in infected BALB/c mice (the most resistant strain). On the other hand, sera from CBA/H mice (a more susceptible strain) showed a strong increase in reactivity along the infection against METE, HS75 and PGK. Many of these immunoreactive proteins have also been detected using sera from human patients with systemic candidiasis, thus indicating the usefulness of the murine model for studying the antibody response in systemic candidiasis. In this work we demonstrate that the combination of two-dimensional electrophoresis with immunoblotting using murine immune sera can be an important tool for the identification of C. albicans antigens and for monitoring the evolution of the disease.

E400P in advanced seminoma of good prognosis according to the international germ cell cancer collaborative group (IGCCCG) classification: the Spanish Germ Cell Cancer Group experience

PURPOSE

To evaluate the efficacy and toxicity of primary chemotherapy with the schedule E400P in the treatment of patients with early stage II (IIa and IIb) and advanced seminoma of good prognosis according to the international classification (IGCCCG).

PATIENTS AND METHODS

Sixty-four patients were included. E400P consisted of cisplatin 25 mg/m2/day and etoposide 100 mg/m2/day for four days, every three weeks. Royal Marsden stages were IIab: 53% and IIc-IV: 47%. Twenty-three percent had high BHCG levels, twenty-seven percent had LDH > 2 x N. Sixty-two patients were of good prognosis according to the Medical Research Council classification.

RESULTS

Response rate was 98% (69% complete remission, 29% residual disease). After a median follow-up of 34 months, treatment failure was seen in 7 patients (11%). Neutropenia (32%) was the most relevant grade 3-4 toxicity. Other important grade 3-4 side effects were found in less than 5%. Three-year time to treatment failure (TTF) was 89% (95% confidence intervals (CI): 80%-97%) for all patients, 91% (95% CI: 80%-99%) for stages IIa-b, and 87% (95% CI: 74%-99%) for stages IIc-IV. Three-year overall survival (OS) was 97% (95% CI: 93%-99%) for all patients and 95% (95% CI: 85%-99%) for stages IIa-b.

CONCLUSIONS

E400P was a very active and safe regimen in good-prognosis advanced seminoma, with low toxicity rates. Definitive comparisons of this regimen with radiotherapy in stages IIa-b or with the more standard E500P or BEP, could be of interest.

Inclusion complexes of nabumetone with beta-cyclodextrins: thermodynamics and molecular modelling studies. Influence of sodium perchlorate

Fluorescence, (1)H-NMR and molecular mechanics have been used to study the inclusion complexes of nabumetone (4,6-methoxy-2-naphthyl-butan-2-one; NAB) with beta-cyclodextrin (beta-CD), randomly methylated-beta (M beta-CD) and hydroxypropyl-beta-cyclodextrins (HP beta-CD). The emission spectrum of NAB shows a maximum whose fluorescence intensity increases with the different beta-CDs growing concentrations. This phenomenon allows calculation of the stability constants at 15, 25, 37 and 45 degrees C. The thermodynamic parameters Delta H degrees and Delta S degrees for the inclusion process were obtained from the temperature dependence of the stability constants. Molecular mechanics calculations, together with proton NMR measurements, for the complex with beta-CD prove that the complex can be formed by penetration through any of the rims, with the naphthalene nucleus included and the substituents outside the cavity. The influence of NaClO(4) in the aforementioned complexes has been analysed by spectrofluorimetric measurements. It has been found that the stability constants for the complexes decrease with the salt concentration; the causes are discussed.

Hereditary hemochromatosis in Spain

The C282Y mutation of the HFE gene has been reported as the main cause of hereditary hemochromatosis (HH). Another missense mutation (H63D) has also been detected at an increased frequency in a compound heterozygote state with the C282Y mutation in HH patients. However, these two mutations are not present in all of the HH patients, indicating that other mutations in the HFE gene, or in other loci, should exist. The present study reports the frequencies of the C282Y and H63D mutations in 74 Spanish HH patients and the results of the sequencing analysis of the HFE exons, intron-exon boundaries, and 588 bp of the 5' region in 5 patients negative for the C282Y mutation. We have detected a high frequency of the C282Y mutation (85.1%) in Spanish HH patients, indicating that this mutation is the most common defect associated with the disease in Spain. The screening of the HFE regions in our patients without the C282Y mutation has revealed the presence of five polymorphisms. However, no other pathological mutations have been found. Therefore, further efforts to characterize the unscreened part of the HFE gene or other loci should be taken to identify the potential genetic factors causing HH in the C282Y-negative patients.

Involvement of K(ATP) channels in diethylstilbestrol-induced relaxation in rat aorta

The estrogens prevent cardiovascular diseases that among other effects could be related to the modulation of the vascular tone via modifying ionic channel permeability. ATP-sensitive K(+) (K(ATP)) channels seem to be involved in diethylstilbestrol-induced relaxation in isolated rat aorta precontracted by noradrenaline (30 nM), since the effect is inhibited by glibenclamide (1--10 microM), and 1 mM tetraethylammonium, but not by 30 mM tetraethylammonium or paxilline. The antiestrogen tamoxifen, the inhibitor of protein kinase A, Rp-cAMPS, and the inhibitor of ornithine decarboxylase, difluoromethylornithine, antagonized diethylstilbestrol-induced relaxation. The association of glibenclamide with these compounds separately did not modify the effect of glibenclamide alone on diethylstilbestrol-induced relaxation. Functional K(ATP) channels are present in rat aorta, since diazoxide induced relaxation sensitive to glibenclamide. Papaverine, dibutyryl cyclic AMP and spermine relaxed isolated rat aorta although this was not sensitive to glibenclamide. The relaxation to forskolin was antagonized by glibenclamide. We conclude that diethylstilbestrol-induced relaxation in rat aorta is related to the modulation of K(ATP) channels. Cyclic AMP-dependent mechanisms and polyamine synthesis may mediate this modulation.