Efecto de una dieta rica en calcio sobre el metabolismo mineral y óseo en ratas / Effect of a calcium-rich diet on bone and mineral metabolism in rats

Objetivo: Una dieta rica en calcio se ha recomendado generalmente para mantener una adecuada salud ósea; no obstante, estudios recientes han despertado la controversia sobre sus beneficios. En este sentido, la mayoría de los estudios existentes en modelos animales están realizados con dietas deficientes en vitamina D. En este estudio se evaluará el efecto de una dieta rica en calcio sobre el metabolismo mineral y la histomorfometría ósea en rata. Además, en células UMR-106 se evaluó el efecto directo del suplemento de calcio sobre la expresión de genes osteogénicos.Material y métodos: Un grupo de ratas wistar macho de aproximadamente 3 meses de edad fue alimentado con dieta de contenido normal de calcio (0,6%) mientras que otro grupo se alimentó con dieta de alto contenido en calcio (1,2%). Transcurridos 20 días se recogieron muestras de orina 24h, sangre para análisis bioquímicos y el fémur para estudio de histomorfometría ósea. In vitro, se estudió la expresión génica de Runx2, Osterix y Osteocalcina en células UMR-106 cultivadas en condiciones de alto contenido en calcio.Resultados: La ingesta de una dieta rica en calcio redujo la concentración de PTH y calcitriol en plasma, aumentó la calciuria y disminuyó la fosfaturia. A nivel óseo, se observó una drástica disminución de la actividad osteoblástica consistente con la bajada de PTH; sin embargo, el volumen trabecular permaneció similar en ambos grupos. In vitro, el suplemento de calcio no disminuyó la expresión de marcadores osteoblásticos en UMR-106, indicando que los efectos in vivo son mayormente indirectos y debidos a la bajada de PTH.Conclusiones: Una dieta de alto contenido en calcio reduce la concentración de PTH y calcitriol en plasma, resultando en una disminución de la actividad osteoblástica. (AU)

Bilateral mirror hand: 2-year follow-up and literature review.

INTRODUCTION: Mirror hand syndrome is a very rare congenital deformity, also called cubital dimelia, characterized by the absence of the thumb, as well as the duplication of the fingers in a symmetrical image and, in some cases, with a duplication of the bones of the forearm. METHODS: The current treatment consists of a thumb reconstruction through thumb pollicization, although there are alternatives such as rotating osteotomy, syndactylization or conservative treatment. In this article we present the case of a girl with a non-classic bilateral mirror hand, the clinical and radiological findings, the bilateral surgical technique in two surgical times with six months of difference and two years follow-up. RESULTS: Complete mobility arches, as well as a good hand holding function were achieved with metacarpophalangeal thumb flexion 0-40o, interphalangeal 5-45o and abduction-adduction 0-50o. We achieved a complete opposition of the new thumb with respect to the other fingers. The strength of the clamp between the fingers was 75.2% of the normal force for her given age, while the strength of the lateral clamp of 66.3% and that of the grip of the fist was 69.1%. CONCLUSION: The surgical technique in the present case (pollicization of the thumb) is an excellent option, achieving objectives of fine and gross motor skills, and good cosmetic results.

INTRODUCCIÓN: Mano en espejo es una deformidad congénita muy rara, en ocasiones conocida como dimelia cubital, caracterizada por la ausencia del dedo pulgar, así como la duplicación de los dedos en imagen simétrica y, de forma clásica, también de los huesos del antebrazo. MÉTODOS: El tratamiento actual consiste en una reconstrucción del pulgar mediante pulgarización, aunque existen alternativas como osteotomía rotadora, sindactilización o el tratamiento conservador. En este artículo se presenta el caso de una niña con mano en espejo no clásica bilateral, los hallazgos clínicos, radiológicos, la reconstrucción quirúrgica de ambas manos consistente en pulgarización tipo Buck-Gramcko bilateral en dos tiempos quirúrgicos con seis meses de diferencia y el seguimiento a corto plazo. RESULTADOS: Presentó arcos de movilidad completos, así como una buena función de sujeción de la mano, se lograron con la flexión del pulgar metacarpofalángica 0-40o, interfalángica 5-45o y abducción-aducción 0-50o. Logramos una oposición del nuevo pulgar con respecto a los otros dedos. La fuerza de la pinza entre los dedos fue del 75.2% de la fuerza normal para la edad, mientras que la fuerza de la pinza lateral fue de 66.3% y la de la empuñadura fue de 69.1%. CONCLUSIÓN: La técnica quirúrgica utilizada en el presente caso demuestra una excelente opción, logrando objetivos de pinza gruesa, pinza fina y agarres, así como un buen resultado cosmético.

Detection of Approximal Caries Lesions in Adults: A Cross-sectional Study.

Detection and management of posterior approximal caries lesions are still problematic. Inspection of approximal surfaces is challenging, and bitewing radiographs are used when direct vision is not possible. Unfortunately, there is no definite radiographic appearance to identify lesion cavitation with absolute certainty. Many lesions detected radiographically within the outer half of dentin are not cavitated, often resulting in unnecessary restorative treatment. Our study compared radiographic depth of approximal caries lesions with presence of cavitation in adults using visual inspection following temporary tooth separation (TTS). We conducted this observational descriptive cross-sectional study at two dental schools in two cities in Chile. Clinicians were unaware of radiographic depths of lesions and examined 147 participants (57.3% female and 42.7% male) following TTS. Using the common classification system that consists of E0 (no lesion), E1 (lesion within the outer half of enamel), E2 (lesion within the inner half of enamel), D1 (lesion within the outer third of dentin), D2 (lesion within the middle third of dentin), and D3 (lesion within the inner third of dentin), a trained dentist evaluated all the processed films. Cavitation was detected in only three sites (0.22%) within the E0 category, seven sites (3.41%) in E1, five sites (14.8%) in E2, four sites (14.8%) in D1, six sites (50%) in D2, and eight sites (61.5%) in D3. Considering that restorative treatment should be indicated strictly for cavitated lesions, our findings support indication for restorative treatment for D3 lesions and the rationale for TTS for D1-D2 caries lesions to allow direct visual inspection to determine whether there is surface cavitation.

In vivo postprandial bioavailability of interesterified-lipids in sodium-caseinate or chitosan based O/W emulsions.

Recent studies have shown that it should be possible to control lipid bioavailability through food structural approaches. Nevertheless, the gastrointestinal-tract physiological conditions must also be considered. To get a better understanding of this phenomenon, we evaluated the effect of emulsification, as well as the use of sodium caseinate or chitosan, on the postprandial bioavailability of interesterified-lipids in O/W emulsions after oral gastric feeding Sprague-Dawley rats. We verified that emulsification may increase lipid absorption, as determined after feeding sodium-caseinate emulsions. However, this result could not be generalised. Interesterified-lipids that were emulsified with chitosan were equally absorbed as those contained in non-emulsified interesterified-lipids/distilled-water blends.

Optimization of the thermophilic anaerobic co-digestion of pig manure, agriculture waste and inorganic additive through specific methanogenic activity.

The anaerobic co-digestion of three wastes (manure, rice straw and clay residue, an inorganic additive) at different concentration levels and their interactive effects on methanogenic activity were investigated in this work at thermophilic conditions in order to enhance hydrolytic activity and methane production. A central composite design and the response surface methodology were applied for the optimization of specific methanogenic activity (SMA) by assessing their interaction effects with a reduced number of experiments. The results showed a significant interaction among the wastes on the SMA and confirmed that co-digestion enhances methane production. Rice straw apparently did not supply a significant amount of substrate to make a difference in SMA or methane yield. On the other hand, clay residue had a positive effect as an inorganic additive for stimulating the anaerobic process, based on its mineral content and its adsorbent properties for ammonia. Finally, the optimal conditions for achieving a thermophilic SMA value close to 1.4 g CH4-COD/g VSS · d(-1) were 20.3 gVSS/L of manure, 9.8 gVSS/L of rice straw and 3.3 gTSS/L of clay.

Frecuencia de colonización por Estreptococo grupo B en embarazadas de 35 a 37 semanas en el Hospital Materno-Infantil San Pablo / Frequency of group B Streptococcus colonization in 35 to 37 weeks pregnant women in the San Pablo Maternal-Child Hospital

La colonización del Estreptococo grupo B en la embarazada está relacionada a patologías perinatales, constituyéndose en una causa muy importante de morbi-mortalidad neonatal. De manera a reducir dicha morbi-mortalidad, el Centro de Control y Prevención de Enfermedades Infecciosas de Estados Unidos desarrolló una estrategia que consiste en realizar el cultivo de muestra tanto vaginal como ano-rectal de todas las mujeres entre 35 y 37 semanas de gestación. El objetivo de este trabajo fue determinar la frecuencia de colonización por Estreptococo β hemolítico grupo B en mujeres gestantes entre las 35-37 semanas de embarazo que concurrieron al Hospital Materno-Infantil San Pablo, Centro de Salud Nº 5, desde abril del 2010 a agosto del 2011. Se realizó un estudio con diseño observacional descriptivo de corte transverso. Las muestras fueron tomadas mediante hisopado de introito vaginal y ano-rectal, colocadas en medio de transporte Stuart y remitidas al Instituto de Investigaciones en Ciencias de la Salud para el cultivo en agar sangre, previo enriquecimiento en caldo Todd Hewitt. La identificación bacteriana se realizó mediante pruebas bioquímicas convencionales y la confirmación mediante aglutinación con látex. La frecuencia de colonización obtenida fue relativamente alta, de 23,6%. Los resultados de este estudio permiten dimensionar la problemática en nuestro país y evidenciar la necesidad de la implementación de un programa a nivel nacional para la detección del Estreptococo grupo B de forma rutinaria en las embarazadas. De esta manera, se podrá disminuir la morbi-mortalidad perinatal y materna con la administración oportuna del tratamiento profiláctico.

The effect of interesterification on the bioavailability of fatty acids in structured lipids.

Fatty acid (FA) profile is a critical factor in the nutritional properties of fats, but, stereochemistry may also play a fundamental role in the rate and extent to which FAs are absorbed and become available. To better understand this phenomenon, we evaluated the bioavailability of FAs in linseed-oil and palm-stearin blends compared to their interesterified mix, using a sn-1,3 stereospecific lipase, to determine if there was any difference in terms of FA availability when using this technology. Test meals were fed through an intragastric feeding tube on Sprague-Dawley male rats after 18 h fasting. Postprandial blood samples were collected after meal or physiological serum (control) administration and the FA profile of plasma lipids was determined. Results showed that modification of the melting profile through interesterification, without altering the bioavailability determined by sn-2 stereochemistry, could delay lipid absorption at the beginning, but had no effect on total lipid absorption.

Progesterone, but not luteal estrogen, is required for the establishment of pregnancy in the new world monkey Cebus apella.

The aim of this study was to examine the requirement of luteal progesterone or luteal estrogen for the establishment of pregnancy in the Cebus monkey and to test in a primate species the synergism between RU 486 and letrozole (LTZ) found in rodents for inhibiting implantation. Exposure of target tissues to either hormone was suppressed during the mid-luteal phase of mating cycles by subcutaneous administration of the antiprogestin (RU 486), the aromatase inhibitor LTZ or the antiestrogen (ICI 182780) on days 4-7 of the luteal phase. Administration of 0.1 or 0.5 mg/kg of LTZ on days 5-7 of the luteal phase caused a profound drop in the levels of E(2) in all animals, whereas administration of ICI 182780 0.2 mg/kg on days 4-6 of the luteal phase had the opposite effect. The pregnancy rate in vehicle treated cycles of the same females was (58.3%). Treatment with RU 486, 0.8 mg/kg/day on days 5-7 of the luteal phase-induced endometrial bleeding in 3/5 mated females none of which became pregnant, whereas pregnancy was confirmed in one of the two animals that did not bled. Treatment with RU 486, 0.4 mg/kg/day alone or with LTZ on days 5-7 or ICI 182780 alone, on days 4-6 of the luteal phase failed to induce bleeding, allowing the establishment of pregnancy in 50.0-66.6% of the animals in these groups. We conclude that in Cebus monkeys, progesterone but not luteal estradiol is required for the establishment of pregnancy and that RU 486 and LTZ do not exhibit in this species the synergism found in rodents.

Cytologic, hormonal, and ultrasonographic correlates of the menstrual cycle of the New World monkey Cebus apella.

Few reports on the reproductive physiology of Cebus apella have been published. In this study we characterized menstrual cycle events by means of vaginal cytology, ultrasonography (US), and hormonal measurements in serum during three consecutive cycles in 10 females, and assessed the probability that ovulation would occur in the same ovary in consecutive cycles in 18 females. The lengths and phases of the cycles were determined according to vaginal cytology. Taking the first day of endometrial bleeding as the first day of the cycle, the mean cycle length +/- SEM was 19.5+/-0.4 days, with follicular and luteal phases lasting 8.2+/-0.2 and 11.3+/-0.4 days, respectively. The follicular phase included menstruation and the periovulatory period, which was characterized by the presence of a large number of superficial eosinophilic cells in the vaginal smear. The myometrium, endometrium, and ovaries were clearly distinguished on US examination. During each menstrual cycle a single follicle was recruited at random from either ovary. The follicle grew from 3 mm to a maximum diameter of 8-9 mm over the course of 8 days, in association with increasing estradiol (E(2)) serum levels (from 489+/-41 to 1600+/-92 pmol/L). At ovulation, the mean diameter of the dominant follicle usually decreased by >20%, 1 day after the maximum E(2) level was reached. Ovulation was associated with an abrupt fall in E(2), a decreased number of eosinophilic cells, the presence of leukocytes and intermediate cells in the vaginal smear, and a progressive increase in progesterone (P) levels that reached a maximum of 892+/-65 nmol/L on days 3-6 of the luteal phase. The menstrual cycle of Cebus apella differs in several temporal and quantitative aspects from that in humans and Old World primates, but it exhibits the same correlations between ovarian endocrine and morphologic parameters.

Oxidation of Hantzsch 1,4-dihydropyridines of pharmacological significance by electrogenerated superoxide.

PURPOSE: To study the reaction of a series of Hantzsch dihydropyridines with pharmacological significance such as, nifedipine, nitrendipine, nisoldipine, nimodipine, isradipine and felodipine, with electrogenerated superoxide in order to identify products and postulate a mechanism. METHODS: The final pyridine derivatives were separated and identified by gas chromatography/mass spectrometry (GC-MS). The intermediates, anion dihydropyridine and the HO2*/HO2- species, were observed from voltammetric studies and controlled potential electrolysis was used to electrogenerate O2*-. RESULTS: The current work reveals that electrogenerated superoxide can quantitatively oxidize Hantzsch dihydropyridines to produce the corresponding aromatized pyridine derivatives. CONCLUSIONS: Our results indicate that the aromatization of Hantzsch dihydropyridines by superoxide is initiated by proton transfer from the N1-position on the 1,4-dihydropyridine ring to give the corresponding anion dihydropyridine, which readily undergoes further homogeneous oxidations to provide the final aromatized products. The oxidation of the anionic species of the dihydropyridine is more easily oxidized than the parent compound.

Post-coital administration of levonorgestrel does not interfere with post-fertilization events in the new-world monkey Cebus apella.

BACKGROUND: Experimental evidence to disprove the belief that emergency contraception with levonorgestrel (LNG) prevents pregnancy by interfering with post-fertilization events is lacking. Here we determined the effect of post-coital and pre-ovulatory administration of LNG on fertility and ovulation, respectively, in the Cebus monkey. METHODS: To determine the effect on fertility, LNG 0.75 mg or vehicle were administered orally or s.c. once or twice within the first 24 h after mating occurring very close to the time of ovulation. Females that became pregnant were aborted with mifepristone and re-entered the study after a resting cycle until each of 12 females had contributed, in a randomized order, two LNG and two vehicle-treated cycles. To determine the effect on ovulation, LNG 0.75 mg or vehicle were injected twice coinciding with follicles smaller or larger than 5 mm in diameter. Six females contributed five treated cycles each. RESULTS: The pregnancy rate was identical in vehicle- and LNG-treated cycles. LNG inhibited or delayed ovulation only when treatment coincided with a follicle <5 mm diameter. CONCLUSION: In Cebus monkeys, LNG can inhibit or delay ovulation but, once fertilization has taken place, it cannot prevent the establishment of pregnancy. These findings do not support the hypothesis that emergency contraception with LNG prevents pregnancy by interfering with post-fertilization events.

Trypanosoma cruzi: inhibition of parasite growth and respiration by oxazolo(thiazolo)pyridine derivatives and its relationship to redox potential and lipophilicity.

Chagas' disease constitutes a therapeutic challenge because presently available drugs have wide toxicity to the host and are generally ineffective in the chronic stages of the disease. A series of oxazolo(thiazolo)pyridene derivatives were studied on Trypanosoma cruzi epimastigote growth and oxygen consumption and their electrochemical (redox) potentials and lipophilicity. The derivatives produced different degrees of parasite growth and respiration inhibition on CL Brener, LQ, and Tulahuen strains of T. cruzi epimastigotes. Respiratory chain inhibition appears to be a determinant of the trypanosomicidal activity of these compounds, since a significant correlation between respiration and culture growth inhibition was found. A similar correlation was found, within the different structural subfamilies, between toxic effects and the ability of the compounds to be oxidized in aqueous media. The inhibition of respiration and of parasite growth in culture increases with the lipophilicity of the substituents on the oxazolopyridine nucleus. No difference in the action of these derivatives was found among the different parasite strains. It is concluded that these compounds may have a potential usefulness in the treatment of Chagas' disease.

MUC1, glycans and the cell-surface barrier to embryo implantation.

As it approaches the maternal surface, the attaching embryo encounters the epithelial glycocalyx, which contains the mucin, MUC1. A high density of MUC1 at the cell surface can inhibit cell adhesion. This raises the possibility of the existence of a uterine barrier to implantation that might allow maternal rejection of poorer quality embryos. To investigate the mechanism of implantation, human embryos were incubated with endometrial epithelial monolayers. Hatched blastocysts were found to attach readily to the epithelial surface. MUC1 was lost from epithelial cells beneath and near to the attached embryo, while normal expression persisted in neighbouring cells.

Muc1 and glycan expression in the oviduct and endometrium of a New World monkey, Cebus apella.

Cebus apella is a New World monkey that has a menstrual cycle of 18-23 days with implantation at approximately luteal Day 5. The aim of this study was to characterize by lectin- and antibody-labeling the distribution of Muc1 and associated glycans on the endometrial and oviductal epithelium during the luteal phase of the cycle. Endometrial histology showed a thin endometrium, with glands extending deeply into the myometrium. No obvious evidence of secretory differentiation in cells of either the superficial or the basal segments of glands could be obtained using a panel of antibodies and lectins that marked epithelial glycoprotein, and glycosylation changes observed in some other primate endometrial cycles were not observed in this study. Antibodies to human MUC1 were shown to cross-react with C. apella, and Muc1 was localized to the apical epithelial surfaces of both the endometrial and the tubal epithelium, with stronger expression in the latter. Again, no cyclic changes were noted. Antibodies specific to the isoform Muc1/Sec showed strong staining at the apical tubal epithelium, but no reactivity was detectable in the luminal epithelium of the uterus. This observation suggests differences between the two glycocalyces and could help to explain why C. apella embryos do not implant in this location.

Effect of nitric oxide synthase inhibitors on ovum transport and oviductal smooth muscle activity in the rat oviduct.

The effect of the inhibition of nitric oxide synthase (NOS) on ovum transport and oviductal motility in rats was investigated. Three different NOS inhibitors were injected into the ovarian bursa at oestrus or day 3 of pregnancy. Oviducts and uteri were flushed 24 h later and the presence of ova was recorded. In oestrous and pregnant rats, treatment resulted in accelerated egg transport, as shown by a decrease in the number of ova present in the oviducts. In cyclic rats, intrabursal injection of 1 mg kg-1 of either N-monomethyl-L-arginine (L-NMMA) or N omega nitro-L-arginine methyl ester (L-NAME) elicited a 30% reduction in the number of ova present in the oviducts, whereas in pregnant animals, the same dose of L-NMMA produced a reduction of 40%. Simultaneous administration of the NO donor spermine NONOate (5 mg kg-1) completely reversed the effect of L-NMMA. Tubal motility was assessed by microsphere displacement analysis within the oviduct. Surrogate ova were transferred to the oviductal lumen at oestrus and 24 h later the effect of intraoviductal injection of 1 microgram L-NMMA or vehicle was assessed. The microspheres in the isthmus showed an oscillating motion, and periods in which movement was not detectable. However, L-NMMA treatment produced a 3.6-fold increase in the maximum instant velocities and a significant reduction in the resting periods of the microspheres compared with the control group (P < 0.001). These results provide evidence that NO inhibition increases tubal motility that results in accelerated ovum transport, and indicate that NO could act as a paracrine signal between different layers of the oviductal wall, providing a role for endogenous NO in regulation of tubal function.

Modified Dakin's solution for cutaneous vibrio infections.

Vibrio species, specifically Vibrio vulnificus, are known to be endemic to warm saltwater environments. As a human pathogen they are capable of causing severe, progressive, necrotizing infections. The lesions are bullous in nature and often require wide surgical debridement due to the aggressiveness of this organism. The literature supports prophylactic antibiotic therapy for those with preexisting hepatic dysfunction or immunocompromise. The authors routinely implement prophylactic antibiotic coverage with doxycycline 100 mg every 12 hours for vibrio in patients with wounds exposed to or acquired in saltwater. In addition, they institute topical therapy with 0.025% sodium hypochlorite solution (modified Dakin's), based on their in vitro study of vibrio sensitivity to antimicrobials. Over the past 2 years, the authors have treated 10 patients with this protocol for cutaneous vibrio infections confirmed by quantitative cultures. None of these patients experienced progression of infection requiring operative debridement-contrary to the aggressive nature of this organism documented in other reports.

Sperm migration into and through the oviduct following artificial insemination at different stages of the estrous cycle in the rat.

In order to examine whether sperm migration into and through the oviduct follows an invariable pattern or is subject to regulation, rats in proestrus, estrus, metestrus, or diestrus were inseminated in the upper third of each uterine horn with 10-20 million epididymal spermatozoa. Three or eight hours later, the numbers of spermatozoa free and adhering to the epithelium in the ampullary and isthmic segments were determined. A significantly higher number of spermatozoa were recovered in estrus than in other stages, at 3 h than at 8 h, and at all stages from the isthmus than from the ampulla. Spermatozoa adhering to the epithelium were observed only in proestrus and estrus and in the isthmus. The effect of exogenous estradiol-17beta (E2) and progesterone (P4) on sperm migration was investigated in rats in which the estrous cycle was inhibited pharmacologically. E2 facilitated sperm migration into the oviduct and P4 antagonized this effect, whereas P4 alone had no effect. Concomitant treatment with E2+P4 induced adhesion of spermatozoa to the oviductal epithelium. In conclusion, the pattern of sperm migration into and through the rat oviduct varies with the stage of the cycle, being dependent on E2 and P4. The adhesion of spermatozoa to the rat oviductal epithelium is stage- and segment-specific and requires the combined action of both hormones.

The expression of alpha(v) and beta3 integrin subunits in the normal human Fallopian tube epithelium suggests the occurrence of a tubal implantation window.

The co-expression of alpha1beta1, alpha4beta1 and alphavbeta3 integrins in the human endometrium coincides with the implantation window. The alphavbeta3 integrin is expressed in the apical surface of the luminal epithelium and may serve to anchor trophoblast cells in the adhesion phase of implantation. Using immunohistochemistry, we compared the expression of alphav, alpha1, alpha4 and beta3 integrin subunits in samples of normal human Fallopian tube and endometrium obtained from five women in the non-receptive period (luteal phase days 2-4) and from another five women in the receptive period (luteal phase days 6-8). The staining was quantified visually on a scale of 0 to ++, according to the intensity and density of stained cells. The alphav subunit is expressed in the Fallopian tube epithelium during both periods in a pericellular distribution. The beta3 subunit is also expressed in the same location, but it is up-regulated during the period of endometrial receptivity. The other subunits are expressed in localizations which are not relevant to trophoblast adhesion and exhibit little or no difference in the level of expression between the non-receptive and receptive periods. Based on these results we postulate that the expression of the beta3 subunit in the human tubal epithelium is under the same systemic controlling signals as in the endometrium and that the normal tubal epithelium may have an implantation window, at about the same time as the endometrium, that affords the opportunity for trophoblast attachment should a 5-7 day embryo be unduly retained in the tube.