Efecto del aceite esencial de orégano sobre el desempeño productivo de ponedoras y la estabilidad oxidativa de huevos enriquecidos con ácidos grasos poliinsaturados / Effect of oregano essential oil on the laying performance and oxidative stability of eggs enriched with polyunsaturated fatty acids

Este estudio evaluó la inclusión de aceite esencial de orégano (AEO, Lippia origanoides Kunth) en dietas enriquecidas con ácidos grasos poliinsaturados (AGPI) sobre el desempeño productivo de ponedoras, el perfil lipídico y la estabilidad oxidativa de huevos en almacenamiento. Se distribuyeron 144 ponedoras en uno de cuatro tratamientos con seis replicas, con el objetivo de de evaluar el efecto del tipo de aceite usado en la dieta (palma o pescado) y la inclusión de AEO sobre las variables de producción, junto con el extracto etéreo, perfil de lípidos y concentración de malonaldehído (MDA), usando un diseño completamente al azar con arreglo factorial y medidas repetidas en el tiempo por los días de almacenamiento (0, 30 y 60 días a 4°C). Los resultados mostraron que el tipo de aceite y el AEO no afectaron el desempeño productivo de las ponedoras (P > 0,05). La concentración de AGPI se incrementó en 16,8% en dietas con aceite de pescado en las que el DHA (ácido docosahexaenoico) también aumentó en un 1,4% (P < 0,05), incrementando la concentración de MDA (malonaldehído) en el huevo (41,6 ng MDA/g d yema), mientras que la suplementación de AEO con 100 g/ton mejoró la estabilidad oxidativa durante el almacenamiento (31.1 ng MDA/g de yema). Durante el almacenamiento la concentración de MDA en la yema incremento con el tiempo alcanzando los 38 ng MDA/g de yema a los 60 días. El AEO mostró potencial como antioxidante natural en la dieta de las ponedoras mejorando la estabilidad oxidativa de los huevos almacenados a 4°C hasta por 60 días.

This study evaluated the inclusion of oregano essential oil (OEO, Lippia origanoides Kunth) in diets enriched with polyunsaturated fatty acids (PUFAs) on productive performance of laying hens, lipid profile and oxidative stability of eggs during storage. 144 hens were distributed in one of four treatments with six replicates in order to evaluate the effect of the type of oil used in the diet (palm or fish) and the inclusion of OEO on the production variables, along with the ethereal extract, lipid profile and malonaldehyde concentration (MDA), using a completely randomized factorial design with the repeated measures of days of storage (0, 30 and 60 days at 4° C). Results show that the type of oil and the OEO did not affect productive performance of layers (P > 0.05). PUFA concentration increased in 16.8% in diets with fish oil in 16.8%, where the DHA also increased by 1.4% (P < 0.05), increasing the MDA concentration in egg (MDA 41.6 ng/g yolk), while supplementation of OEO at a level of 100 g/ton improved oxidative stability during storage (MDA 31.1 ng/g yolk). During storage the concentration of MDA in the yolk increased with time reaching 38 ng/g yolk at 60 days. The OEO showed potential as a natural antioxidant in the diet of layers hens improving the oxidative stability of eggs stored at 4°C up to 60 days.

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.

Aflatoxins in pozol, a nixtamalized, maize-based food.

To determine whether pozol, a nixtamalized maize-based food was contaminated with aflatoxins, samples of non-fermented pozol were collected during the period November 2002 to April 2003 from local markets at Comitan in Chiapas, Mexico. The samples were analyzed for the presence of aflatoxins. Nineteen out of one hundred and eleven samples were contaminated with aflatoxin B2 (AFB2) and traces of aflatoxin B1 (AFB1). The percentage of samples contaminated with AFB2 in pozol prepared with white maize was 5.4%. Pozol mixed with toasted cacao paste had a contamination rate of 41.5%. No aflatoxins were detected in pozol prepared with yellow maize. It was found that only 1 of 19 contaminated samples had aflatoxin concentrations above 20 ppb.

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.

Extra-abdominal pneumodissection after laparoscopic antireflux surgery.

The presence of pneumoperitoneum during laparoscopic antireflux surgery can lead to the dissection of carbon dioxide into the mediastinum, retroperitoneum, subcutaneous tissues, and neck (pneumodissection). The purpose of this study is to describe the incidence, extent, duration and pathways of pneumodissection during laparoscopic antireflux surgery. Twenty patients who underwent laparoscopic antireflux surgery from August 1998 through May 1999 were studied. Physical examination and chest radiographs were performed in the recovery room and each day postoperatively. Noncontrast computerized tomography (CT) of the neck, chest, and upper abdomen was also performed on postoperative day one. Subcutaneous emphysema and radiologic evidence of pneumodissection occurred commonly and typically resolved within 4 days postoperatively. The incidence of pneumomediastinum (85%) seen on CT scan was similar to that of pneumodissection into the neck (80%). The most common pathway of dissection of gas was through the anterior mediastinum and into the neck through the carotid space. Other findings on CT scan revealed pneumoperitoneum in 70 per cent, pneumoretroperitoneum in 10 per cent, and pneumothorax in 0 per cent. The dissection of gas into the mediastinum, neck, and subcutaneous tissues is very common after laparoscopic antireflux surgery. Subcutaneous emphysema on physical examination and radiographic pneumodissection typically resolves within 3 to 4 days. After this time one should consider the presence of any substantial amount of gas as a potential complication related to the procedure.

[Diuretics and their current role in the treatment of essential arterial hypertension]. / Diureticos y su rol actual en el tratamiento de la hipertensión arterial esencial.

Diuretics have been most commonly used to treat hypertension in the last 25 years. Their tolerance is good, they have been effective specially in negroes, older and obese patients and they are relatively inexpensive. The emergence of new and more potent drugs: beta blockers, calcium antagonists, and ACE inhibitors, has led to a decrease in diuretic use. Hyperglycemia and lipid disorders induced by diuretics have been invoked to explain the lack of effect on coronary mortality among treated hypertensive patients. Hypokalemia induced by diuretics has been suspected as the cause for sudden deaths. However, these effects are not sufficiently proven and do not warrant, at present, the elimination of diuretics in the treatment of hypertension.