Humoral immune response against epidermal growth factor encapsulated in dehydration rehydration vesicles of different phospholipid composition

We investigated the influence of dehydration-rehydration vesicles (DRV) phospholipid composition and the addition of other components on human recombinant epidermal growth factor (hrEGF) encapsulation efficiency and its release from liposomes. Encapsulation of EGF into DRV composed of phosphatidylcholine with different unsaturation levels was around 20-35%. The best result was obtained with dipalmitoyl phosphatidylcholine: cholesterol (DPPC:Ch) liposomes (35%) corresponding to the lowest hrEGF release during one month of storage. Even with this phospholipid composition, modification of the DRV procedure by including an extrusion step did not improve hrEGF encapsulation efficiency, rendering less stable particles. The inclusion of recombinant P64k from Neisseria meningitidis (rP64k), as such or conjugated to hrEGF, decreased the encapsulation efficiency of the latter protein into DRV or freeze and thaw multilamellar vesicles (FATMLV). The hrEGF release from liposomes could be related to the interaction between this polypeptide and the bilayer, as evidenced by increased carboxyfluorescein release from hrEGF-DRV; less susceptibility to fluorescence quenching by acrylamide in the presence of liposomes; and a measurable decrease of phospholipid phase transition Delta enthalpy (DeltaH). DRV comprising saturated phospholipids (DPPC:Ch or distearoyl phosphatidylcholine [DSPC]:Ch) and containing the conjugate EGF-P64k induced a more efficient immune response against hrEGF than unsaturated phospholipid and alum in terms of total IgG, IgG(2a), and IgG(2b) subclasses and the ability of antibody to inhibit the interaction of the EGF receptor with hrEGF.

Effects of hydroxypropyl-beta-cyclodextrin on the chemical stability and the aqueous solubility of thalidomide enantiomers

The aim of this work was to study the effect of hydroxypropyl-beta-cyclodextrin on the solubility and stability of thalidomide enantiomers in aqueous solutions for clinical oral administration to be used in HIV-infected children. For this reason racemic thalidomide was added to solutions containing different concentrations of hydroxypropyl-beta-cyclodextrin. True complexes were obtained by using hydroxypropyl-beta-cyclodextrin and the solubility of both thalidomide enantiomers was increased directly depending on the amount of hydroxylpropyl-beta-cyclodextrin in the medium although no enantioselective differences were observed at 37 degrees C. The chemical stability of thalidomide enantiomers is clearly improved by hydroxypropyl-beta-cyclodextrin. No enantioselective degradation of thalidomide was observed in sodium chloride solution (0.9%) samples stored at 6 degrees C for nine days when hydroxypropyl-beta-cyclodextrin was employed as excipient. Therefore a thalidomide solution suitable for oral administration can be prepared by adding hydroxypropyl-beta-cyclodextrin at 10% (w/v).

Comparative study of blood lead levels in Uruguayan children (1994-2004)

Lead does not fulfill any physiological function in the human body. It is generally accepted that the blood lead level (BLL) is the best exposure index, as there is an excellent correlation between the actual exposure of the individual and the concentration of lead in blood. In Uruguay, lead contamination becomes a matter of public concern in 2001, giving rise to a sensitization in the population, which in many cases brought about a change in hygienic and dietary habits of the children. In 2004, after the leaded gasoline phasing out process in Uruguay was completed, we studied non-exposed children to correlate BLL with variables such as age, sex, area of residence, and available environmental lead data and compared these results with those from our similar screening studies 10years ago. The main result of this comparison is that BLL from children in our country had a significant decrease between 1994 and 2004.

Relationship between personality traits and cooperation of adolescent orthodontic patients

OBJECTIVE

To establish the relationship between the personality traits of the adolescent and his or her cooperation with the orthodontic treatment.

MATERIALS AND METHODS

From a sample of 70 adolescent orthodontic patients (46 girls and 24 boys) between 12 and 15 years of age (average age, 13.4 +/- 1.1 years), the patients' personality traits were evaluated by using a personality questionnaire (16 Personality Factors-Adolescent Personal Questionnaire) and the degree of patient cooperation was assessed through the cooperation test (Orthodontic Patient Cooperation Scale [OPCS]). The cutting point for the assessment of cooperation on the OPCS questionnaire (noncooperation vs cooperation) was carried out through the receiver operating characteristic (ROC) analysis of curves. A chi2 test with Yates correction (P < or = .05) was applied to evaluate the associations between the degree of cooperation and the scales of personality, gender, or age.

RESULTS

The cutting point for cooperation as assessed by the OPCS by means of ROC analysis was 380. No statistically significant relations were found between the degree of cooperation and the scales of personality, gender, or age.

CONCLUSIONS

The results of the current study indicate that the personality traits alone of adolescents do not predict cooperation during treatment.

Association between heroin dependence and 5-HT2A receptor gene polymorphisms

OBJECTIVE

To investigate the association between four polymorphisms of the 5-HT(2A) receptor and 5-HT transporter genes and heroin dependence.

METHODS

113 heroin- dependent patients (DSM-IV criteria) and 420 unrelated healthy controls from Asturias (Northern Spain) were genotyped using standard methods.

RESULTS

There was an apparent difference in the distribution of genotypes for A-1438G polymorphisms (p = 0.024, not significant after Bonferroni correction). The 5-HT(2A) -1438A allele was significantly more common in patients than controls [0.55 and 0.45, respectively; corrected p = 0.042, OR = 1.51 (95% CI = 1.13-2.03)]. An interaction was observed between A-1438G of 5-HT(2A) and 5-HTT polymorphisms. The association between the -1438AA vs. AG/GG genotypes and heroin dependence was enhanced in the presence of 12-repeat 5-HTT VNTR and short 5-HTTLPR alleles [24.8% in heroin-dependent patients vs. 12.6% in controls; corrected p = 0.045, OR = 2.28 (95% CI = 1.36-3.82)].

CONCLUSIONS

Our findings support a contribution of the 5-HT(2A) gene to susceptibility to heroin dependence, as well as a possible synergistic effect of 5-HT(2A) and 5-HTT genes on susceptibility to heroin dependence.

Lead contamination in Uruguay: the "La Teja" neighborhood case

Lead, ubiquitous in the environment as a result of mining and industrialization, is found as a contaminant in humans although it has no known physiological function there. Lead-exposed children are known to be the population with the highest potential health risks. The recommended biomarker to assess environmental lead exposure in animals is lead level in blood. Before 2001, the Department of Toxicology and Environmental Hygiene was the only team to produce human monitoring data on Uruguayan populations (Manay 2001a,b; Mañay et al. 1999). Lead pollution in Uruguay first received official attention during the 2001 La Teja poisoning episode. It was in the La Teja neighbourhood of Montevideo that high BLL were found in children (as high as 20 microg/dL), prompting corrective responses from Health and Environmental authorities. Growing awareness of environmental lead pollution and consequential human health effects from that event, resulted in public debate and demands for solutions from Health and Environmental authorities. Citizens demanded public disclosure of information concerning lead pollution and wanted action to address contaminated Uruguayan sites. In response, the Ministry of Health assembled an interinstitutional multidisciplinary committee, with delegates from health, environmental, labor, educational, and social security authorities, as well as community nongovernmental organizations (NGOs), among others. The University of the Republic was designated to serve as the main responsible entity for technical advice and support. After 2001, new research on lead pollution was undertaken and included multidisciplinary studies with communities in response to health risk alerts. The main emphasis was placed on children exposed to environmental lead. Major sources of Uruguayan lead contamination, similar to those in other developing countries, result from metallurgical industries, lead-acid battery processing, lead wire and pipe factories, metal foundries, metal recyclers, leaded gasoline (before December 2003), lead water pipes in old houses, and scrap and smelter solid wastes, among others. Nonoccupational lead exposure usually results from living in or near current or former manufacturing areas or improper handling of lead-containing materials or solid wastes (a particularly important health risk for children). In this chapter, we reviewed available studies published or reported after the pollution events first announced in 2001. These studies include data on exposure, health, and actions taken to mitigate or prevent lead exposure from pollution events in Uruguay. Uruguay adopted CDC's 10 microg/dL as the reference BLL for children (CDC 1991) and a BLL of 30 microg/dL for workers (from the ACGIH standard). Environmental authorities adopted the Canadian reference concentrations for soil: residential and playgrounds (> 140 mg/kg) or industrial areas (> 600 mg/kg) (CCME 2006). Most studies reviewed addressed soil pollution as the main source of lead exposure. Results of thousands of analyses indicated that most children had BLL above reference intervention limits. A significant decrease in BLL was also found over time in the study results, demonstrating the importance of medical intervention, nutrition, and environmental education. The severity of lead pollution discovered required official governmental actions, both to reduce sources of lead contamination and to address the health implications for children who had been exposed to environmental or industrial lead pollution. Dogs were discovered to be useful sentinels for environmental lead pollution; they had higher BLL than children when exposed to the same polluted environment and developed symptoms of lead intoxication earlier and at lower BLL than did children. This same pattern was also observed in families with children and pet dogs living in the La Teja neighborhood. This discovery renders dogs prospectively useful in lead pollution monitoring and diagnosis, particularly in developing countries. BLL results from similar human lead exposure studies conducted 10 yr apart showed significant BLL reductions, after 10 yr, for nonoccupationally exposed Uruguayans. The phase-out of leaded gasoline is thought to have contributed to this improvement. New laws to address occupational and environmental exposures were passed to prevent new cases of lead contamination, and new research studies are underway to monitor lead pollution. Moreover, a systematic surveillance screening program for lead workers and children is planned, although it is not yet underway. The sensitization of the public to the lead pollution problem has been a key driver of governmental action to mitigate and prevent further lead pollution in Uruguay. The changes made since 2001 appear to have yielded positive results. BLL from different populations studied more recently show decreased lead levels, suggesting a lower contribution of environmental lead to exposure of children and nonoccupationally exposed adults. The diverse analytical data collected on lead pollution in Uruguay between 2001 and 2004 were the main ingredient that allowed effective identification of lead pollution in Uruguay and paved the way for official intervention to prevent new pollution events. Nevertheless, full research studies must still be done, including both spot analysis of environmental soil, air, and water samples, and extensive screening of BLL. Future health and environmental actions are needed, not only to remediate known areas of lead pollution, but also to investigate other sources of potential health risks.

Type 2 diabetes - a matter of failing beta-cell neogenesis? Clues from the GK rat model

Now that reduction in beta-cell mass has been clearly established in humans with type 2 diabetes mellitus (T2D), the debate focuses on the possible mechanisms responsible for decreased beta-cell number. Appropriate inbred rodent models are essential tools for this purpose. The information available from the Goto-Kakizaki (GK) rat, one of the best characterized animal models of spontaneous T2D, is reviewed in such a perspective. We propose that the defective beta-cell mass in the GK model reflects mostly a persistently decreased beta-cell neogenesis. The data discussed in this review are consistent with the notion that poor proliferation and/or survival of the endocrine precursor cells during GK foetal life will result in a decreased pool of endocrine precursors in the pancreas, and hence an impaired capacity of beta-cell neogenesis (either primary in the foetus or compensatory in the newborn and the adult). As we also demonstrated that beta-cell neogenesis can be pharmacologically reactivated in the GK model, our work supports, on a more prospective basis, the concept that facilitation of T2D treatment may be obtained through beta-cell mass expansion after stimulation of beta-cell regeneration/neogenesis in diabetic patients.

Defective IGF2 and IGF1R protein production in embryonic pancreas precedes beta cell mass anomaly in the Goto-Kakizaki rat model of type 2 diabetes

AIMS/HYPOTHESIS

The Goto-Kakizaki (GK) rat is a spontaneous model of type 2 diabetes. Defective beta cell mass detectable in late fetal age precedes the onset of hyperglycaemia. Our hypothesis was that an embryonic IGF production deficiency might be involved in beta cell mass anomaly in the diabetic GK rat. To test this, we evaluated during pancreatic organogenesis: (1) the beta cell development in GK rats on embryonic day (E) 13.5 and E18.5; (2) IGF2 and IGF1 receptor (IGF1R) pancreatic protein production on E13.5 and E18.5; (3) the in vitro development of GK pancreatic rudiment on E13.5; and (4) the in vitro effect of IGF2 addition on beta cell mass.

MATERIALS AND METHODS

Beta cell quantitative analyses were determined by immunohistochemistry and morphometry. IGF2 and IGF1R pancreatic protein production was evaluated using western blot analyses. Dorsal pancreatic rudiments were dissected on E13.5, separated from surrounding mesenchyme and cultured for 7 days without or with recombinant IGF2.

RESULTS

While beta cell mass was already decreased on E18.5, the differentiation of the first beta cells was in fact normal in E13.5 GK pancreas. Moreover, defective IGF2 and IGF1R protein production was detected in GK pancreatic rudiment as early as E13.5. The isolated GK pancreatic rudiment as maintained in vitro mimics the GK beta cell deficiency observed in vivo. This last approach enabled us to show that GK beta cells were fully responsive to IGF2 as far as their net growth is concerned.

CONCLUSIONS/INTERPRETATION

In diabetic GK rat, defective IGF2 and IGF1R protein production in embryonic pancreas precedes beta cell mass anomaly. IGF2 supplementation expands the pool of beta cells.

Outcome of patients with acute promyelocytic leukemia failing to front-line treatment with all-trans retinoic acid and anthracycline-based chemotherapy (PETHEMA protocols LPA96 and LPA99): benefit of an early intervention

To determine prognosis of acute promyelocytic leukemia (APL) failing to front-line therapy with all-trans retinoic acid (ATRA) and anthracyclines, outcome of 52 patients (32 M/20 F; age: 37, 3-72) included in PETHEMA trials LPA96 and LPA99 who presented with either molecular failure (MOLrel, n=16) or hematological relapse (HEMrel, n=36) was analyzed. Salvage therapy consisted of ATRA and high-dose ara-C-based chemotherapy (HDAC) in most cases (83%), followed by stem-cell transplantation (autologous, 18; allogeneic, 10; syngeneic, 1). Fourteen patients with MOLrel (88%) achieved second molecular complete response (molCR), whereas 81% HEMrel patients responded to second-line treatment, with 58% molCR. After median follow-up of 45 months, four MOLrel and 18 HEMrel patients, respectively, experienced a second relapse. Outcome after MOLrel compared favorably to HEMrel, with longer survival (5-year survival: 64+/-14 vs 24+/-8%, P=0.01) and lower relapse risk (5-year relapse risk: 30+/-13 vs 64+/-9%; P=0.044). Additionally, age <or=40 and male gender were favorable variables for survival, whereas molecular response predicted longer leukemia-free survival. In conclusion, early institution of salvage therapy at molecular failure, before onset of hematological relapse, is beneficial in APL. Moreover, given the poor outcome of HEMrel managed with ATRA and HDAC, use of alternative therapeutic strategies in this setting is warranted.

Structural and functional characterization of a recombinant sticholysin I (rSt I) from the sea anemone Stichodactyla helianthus

Sticholysins I and II (Sts I and II) are two potent cytolysins from the sea anemone Stichodactyla helianthus. These isoforms present 13 substitutions, with three non-conservative located at the N-terminus. St II is considerably more hemolytic than St I in human red blood cells, a result explained by the smaller number of negatively charged groups present at St II's N-terminus. In the present work, we have obtained a recombinant St I (rSt I), differing from the wild type in a single amino acid residue (E16Q). This pseudo-wild type is structurally similar to St I and shows a similar capacity to interact with and form pores in model membranes. This was assessed by the intrinsic fluorescence increase in the presence of liposomes, their adsorption to bilayers (measured by SPR), their concentration at the air-water interface, their interaction with lipid monolayers and their capacity to promote the release of carboxyfluorescein entrapped in liposomes. In spite of these similarities, rSt I presents a larger hemolytic activity in human red blood cells than St I, being intermediate in activity between Sts I and II. The results obtained in the present work emphasize that even the change of one single E by Q at the N-terminal segment may modify the toxin HA and show that this functional property is the most sensitive to subtle changes in the protein primary structure.

Undernutrition does not alter the activation of beta-cell neogenesis and replication in adult rats after partial pancreatectomy

In previous work, we demonstrated that a 65% protein calorie food restriction started during the third trimester of gestation in rats caused a reduced beta-cell mass at 4 days of life that persisted until adult age. In this study with adult undernourished (U) rats, we investigated 1) whether undernutrition affects the beta-cell growth potential and both beta-cell proliferation and differentiation and 2) the implication of the IGFs, highly responsive to nutritional status, in these processes. To this end, we used the 90% pancreatectomy (Px) procedure in U and control (C) adult rats. The results show that, on day 2 after Px, beta-cell replication was significantly higher in C rats, whereas the beta-cell neogenesis was markedly increased in U/Px rats. Both the serum levels of IGF-I and the liver IGF-I mRNA expression were reduced in adult U rats before and after Px compared with C rats. Pancreatic IGF-I mRNA expression was reduced in U animals on day 0. However, on day 2 after Px, the increase of pancreatic IGF-I mRNA expression was significantly higher in U rats than in C rats. These data suggest that beta-cells still have the capacity to regenerate in the adult U rats, with a higher efficiency than C rats on day 2, and that both beta-cell neogenesis and beta-cell replication are stimulated. The increased pancreatic IGF-I mRNA may be instrumental in these processes.

The genotype-phenotype correlation of hereditary multiple exostoses

Hereditary multiple exostoses (HME) is an autosomal dominant condition with a wide spectrum of clinical presentations. The purpose of this study was to determine the relationship between the genotype and the phenotype in HME. Thirty-two affected individuals from 10 families participated in the study. An extensive description of HME phenotype in terms of the anatomical burden of disease involved clinical and radiographic examinations and evaluation of 76 parameters. Mutations were determined by sequencing the EXT 1 and EXT 2 genes. Mutations were found in eight families (26 individuals), with one mutation previously reported in the literature and seven novel mutations. There were seven subjects with an EXT 1 mutation and 16 with an EXT 2 mutation. Patients with EXT 1 mutation were found to have more exostoses, more limb malalignment with shorter limb segments and height, and more pelvic and flatbone involvement. A genotype-phenotype correlation exists in HME, with patients with EXT 1 mutations having a higher degree of anatomical burden.

Signal transduction pathways involved in non-genomic action of estrone on vascular tissue

Previously we demonstrated that estrone non-genomically regulates rat aortic NOS and COX activity and that this effect depends on ovarian activity. The purpose of the present study was to characterize this effect and investigate the participation of phospholipase C and phophatidylinositol-3-kinase system in the intracellular transduction pathway involved in the response. Using aortic strips isolated from female fertile rats we showed that estrone stimulate nitric oxide synthase and cyclooxygenase in a short time interval (5-20 min), and that NO production was dependent in part on PGI2 production since 1 microM indomethacin significantly reduced this free radical production. Injection of 17-beta-estradiol to ovariectomized rats restored tissue capacity to rapidly increase NO production in response to "in vitro" treatment with 1 nM estrone. We also demonstrated that in aortic strips isolated from intact animals estrone elicited a rapid phospholipase C activation, inducing a biphasic increase in diacylglycerol generation (peaking at 45 s and 5 min). The presence of protein kinase C inhibitor chelerythrine did not prevent the increase of NO released in response to hormone treatment. We proved that PI3K-Akt system does not mediate NOS and COX activation. However, PLC activation was dependent on PI3K since presence of LY 294002 in the incubation medium abolished estrone-induced DAG increment. We concluded that, estrone rapid action on vascular tissue involves a cross talk between NOS and COX system, and the activation of PLC/DAG/PKC transduction pathways.

[A review of the clinical application of dyes in gastrointestinal chromoendoscopy, and their magistral formulation]

OBJECTIVE

To review the drug compounding of dyes employed in chromoendoscopy, and their clinical effectiveness.

METHOD

A literature search in Medline, Cochrane Library, and Micromedex was carried out with the term chromoendoscopy as a keyword, and the search was then repeated for each dye found in association with the term endoscopy. A number of monographs, scientific journals, and references quoted in selected papers were also reviewed. Papers collected were then classified according to their methodology.

RESULTS

Ninety-six references were found, their original article being recovered for only 57 of these - 13 clinical trials, 21 case series, and 11 reviews. References were found for 7 dyes. Main indications, evidence of effectiveness, administration route, and drug formulation are described for each dye.

CONCLUSIONS

The number of papers involved is high, but their accessibility is limited. Evidence is overall scarce, but high in cases such as methylene blue for Barrett s esophagus, lugol in the detection of esophageal carcinoma, and indigo carmine for colonic hyperplastic polyp differentiation. Drug compounding is rather simple, but scarcely developed.

Effect of type and level of fish oil supplementation on yolk fat composition and n-3 fatty acids retention efficiency in laying hens

1. Laying hen performance and yolk fat fatty acid (FA) concentrations were evaluated with respect to the inclusion in the diet of different sources and levels of marine fish oil (MFO). 2. Twelve diets were arranged factorially, with three sources (MFO1, MFO2_EPA, MFO3_DHA) and four levels of inclusion (15, 30, 45 and 60 g/kg) of MFO. 3. Type of diet had little effect on egg production traits, although laying rate and shell thickness slightly decreased at the highest level of MFO supplementation. 4. An increase in level of inclusion of MFO from 15 to 60 g/kg linearly increased concentrations of C20:5 n-3, C22:5 n-3, C22:6 n-3 and total n-3 FA in yolk fat, but greatly impaired their efficiencies of deposition (g retained/g ingested). 5. An interaction between type and dietary concentration of MFO was found, as the reduction in efficiency of retention of n-3 FA in egg fat with level of MFO was less when the proportion of n-3 in total FA decreased or when that of DHA in total n-3 FA increased. 6. MFO3_ DHA was more efficiently used for total n-3 FA yolk deposition than MFO2_EPA at a similar total n-3 FA intake. 7. Dietary inclusion of MFO reduced LC n-6 FA yolk fat content, which additionally decreased the ratio between total n-6 and total n-3 FA in egg fat. 8. Regression equations were calculated in order to predict efficiency of retention and n-3 FA concentration of yolk fat in the range of diets studied.