PLGA nanoparticles of a new cinnamic acid derivative inhibits cellular proliferation on breast cancer cell line MCF-7 in a PPARγ dependent way.

Currently, cancer treatments are highly invasive, and they have been associated with a lot of adverse effects that put patient integrity at risk. Therefore, research of novel molecules and delivery systems capable of achieving a therapeutic effect that modifies inhibits and reduces the proliferative activity in cancer cells and, at the same time, reduce adverse effects associated with conventional therapies is imperative. In this study, we analyzed the biological effect of a novel cinnamic acid derivative, 3,4-dichlorobencil-p-phenoxylcilamide, in polymeric nanoparticles over MCF-7 breast cancer cells. The nanoparticulated system showed an inhibitory influence over cellular metabolism at equal or higher concentrations than 25 µM of 3,4-dichlorobencil-p-phenoxylcilamide, which is associated with PPARγ transcriptional activity, in addition to the decrease in the proliferation antigen Ki-67 basal levels. Those results position this kind of nanoscale system as an alternative on breast cancer treatment and lay the basis for research on the action mechanism associated with its cellular metabolism modulation and relationship with another hallmark on breast cancer cellular models.

Effect of the administration program of 2 ß-adrenergic agonists on growth performance and carcass and meat characteristics of feedlot ram lambs.

The aim of the study was to determine the effects of 3 feeding dose programs of the ß-adrenergic agonists (ß-AA) ractopamine hydrochloride (RH) or zilpaterol hydrochloride (ZH) for the final 30 d before slaughter on growth performance and carcass and meat characteristics of feedlot ram lambs. Eighty-four Dorper × Katahdin ram lambs (30.0 ± 1.6 kg) were blocked by BW and randomly assigned to pens (4 lambs per pen and 3 pens per treatment). Pens within a block were assigned randomly to 1 of 7 dietary treatments: 1) control (CTL) = diet without ß-AA; 2) RH constant (RHC) = 20.0 mg/kg of RH, d 1 to 30; 3) RH increasing (RHI) = 10.0 mg/kg, d 1 to 10; 20.0 mg/kg, d 11 to 20; and 30.0 mg/kg, d 21 to 30; 4) RH decreasing (RHD) = 30.0 mg/kg, d 1 to 10; 20.0 mg/kg, d 11 to 20; and 10.0 mg/kg, d 21 to 30; 5) ZH constant (ZHC) = 6.0 mg/kg of ZH, d 1 to 30; 6) ZH increasing (ZHI) = 3.0 mg/kg, d 1 to 10; 6.0 mg/kg, d 11 to 20; and 9.0 mg/kg d 21 to 30; and 7) ZH decreasing (ZHD) = 9.0 mg/kg, d 1 to 10; 6.0 mg/kg, d 11 to 20; and 3.0 mg/kg, d 21 to 30. Overall, ß-AA supplementation reduced DMI (P < 0.001) compared with CTL lambs, but lambs fed RHI and ZHI programs had greater (P < 0.05) total BW gain, ADG, and G:F. Carcass weight was improved (P < 0.05) by RHI and ZHI programs, but dressing percentage was enhanced (P < 0.05) by only ZHC or ZHI treatments. Fat thickness and yield grade were reduced (P < 0.05) by ZH or RH regardless of feeding program. Most LM characteristics (pH, moisture loss, and chemical composition) were not different among treatments (P > 0.05), with the exception of fat content that was reduced (P < 0.001) in lambs fed ß-AA, and diameter of muscle fibers that was increased (P < 0.05) by ZHI treatment. Constant and increasing doses of ZH reduced (P < 0.05) the a* value of LM and semitendinosus muscles, with no effects on L* or b* values. The mass of liver was reduced (P < 0.05) in ZHI-treated lambs compared with CTL lambs, and plasma urea concentration was reduced (P < 0.05) by RH or ZH administration regardless of feeding program, although there were no other differences in organ mass weight (P ≥ 0.35) or blood metabolites (P ≥ 0.16). Increasing doses of RH or ZH augmented the growth performance response without negative effects on organ mass weight or blood metabolites. Although a ZHI program improved carcass characteristics, the increased LM fiber diameter of lambs fed ZHI program could be unfavorable because of the potential negative effect on tenderness.

Long-term eutrophication diagnosis of a high altitude body of water, Zimapán Reservoir, Mexico.

Zimapán Reservoir is located in the central plateau of Mexico. Its main purpose is the generation of electric energy, and it has a high mean depth (52.40 m). The reservoir has two tributaries: the Tula River, which receives the wastewater of Mexico City, and agricultural run-off; and the San Juan River, with municipal and industrial wastewater. The population growth together with the dry climate are generating pressure on the water resource. The purpose of this study is to characterize the trophic state of Zimapán Reservoir and its trend on a five year study. It is warm with the presence of thermocline between 8 and 14 m. It was found hypereutrophic for the nutrient concentration (average TP and TN of 1,381 and 5,977 microg.L(-1), respectively), and eu-hypereutrophic in case of the Secchi disk (1.94 m) and the chlorophyll concentration (38 microg.L(-1)). The trend analysis showed and increment of nutrients in the period, but a decrement in Secchi disk and chlorophyll results. Nutrients are present in a very high concentration. The reservoir is gradually increasing its trophic state condition.

The tape-stripping technique as a method for drug quantification in skin.

Quantification of drugs within the skin is essential for topical and transdermal delivery research. Over the last two decades, horizontal sectioning, consisting of tape stripping throughout the stratum corneum, has become one of the traditional investigative techniques. Tape stripping of human stratum corneum is widely used as a method for studying the kinetics and penetration depth of drugs. This paper shows the applications of the tape stripping technique to quantify drug penetration through the skin, underlining its versatile application in the area of topical and transdermal drugs.

Applications of thermo-reversible pluronic F-127 gels in pharmaceutical formulations.

It is, sometimes, desirable to maintain a constant plasma drug concentration within the therapeutically effective concentration range. The use of high viscosity hydromiscible vehicles such as hydrophilic gels, is one of various approaches for controlled drug delivery, and represents an important area of pharmaceutical research and development. Of these systems, Pluronic F-127 (PF-127) provides the pharmacist with an excellent drug delivery system for a number of routes of administration and is compatible with many different substances. Gels containing penetration enhancers have proven to be especially popular for administering anti-inflammatory medications since they are relatively easy to prepare and very efficacious.

Venom of the crotaline snake Atropoides nummifer (jumping viper) from Guatemala and Honduras: comparative toxicological characterization, isolation of a myotoxic phospholipase A(2) homologue and neutralization by two antivenoms.

A comparative study was performed on the venoms of the crotaline snake Atropoides nummifer from Guatemala and Honduras. SDS-polyacrylamide gel electrophoresis, under reducing conditions, revealed a highly similar pattern of these venoms, and between them and the venom of the same species from Costa Rica. Similar patterns were also observed in ion-exchange chromatography on CM-Shephadex C-25, in which a highly basic myotoxic fraction was present. This fraction was devoid of phospholipase A(2) activity and strongly reacted, by enzyme-immunoassay, with an antiserum against Bothrops asper myotoxin II, a Lys-49 phospholipase A(2) homologue. A basic myotoxin of 16 kDa was isolated to homogeneity from the venom of A. nummifer from Honduras, showing amino acid composition and N-terminal sequence similar to those of Lys-49 phospholipase A(2) variants previously isolated from other crotaline snake venoms. Guatemalan and Honduran A. nummifer venoms have a qualitatively similar toxicological profile, characterized by: lethal; hemorrhagic; myotoxic; edema-forming; coagulant; and defibrinating activities, although there were significant quantitative variations in some of these activities between the two venoms. Neutralization of toxic activities by two commercially-available antivenoms in the region was studied. Polyvalent antivenom produced by Instituto Clodomiro Picado was effective in the neutralization of: lethal; hemorrhagic; myotoxic; coagulant; defibrinating; and phospholipase A(2) activities, but ineffective against edema-forming activity. On the other hand, MYN polyvalent antivenom neutralized: hemorrhagic; myotoxic; coagulant; defibrinating; and phospholipase A(2) activities, albeit with a lower potency than Instituto Clodomiro Picado antivenom. MYN antivenom failed to neutralize lethal and edema-forming activities of A. nummifer venoms.

[The penumbra area]. / El área de penumbra.

INTRODUCTION: Habitually, when one speaks about penumbra area it refers to an ischemic region with the risk of permanent affection but potentially recoverable, that extend during a period of 4 to 6 hours. Nevertheless, with the reperfusion we cannot always get a neurofunctional recovery, or hinder the extension of the infarct. In this work, the author checked the mechanisms that participate in the lesion of penumbra area, as far as extension, duration as well as their relation with the therapeutic windows. DEVELOPMENT: Penumbra is a brain tissue at risk of infarct but is potentially recoverable and receives a variable level of cerebral blood flow (diminished, normal or augmented) which presents a functional alteration principally of its metabolism that is produced by various mechanisms like phenomenon of no reflow, reperfusion injury, hemodynamics disorders, spreading depolarization, delayed neural death, deafferentation (diaschisis), postischemic exofocal neural death, slowly progressive neural damage, among other alteration different a simple lesion by energy failure, these disorders may act during several months. CONCLUSION: Three therapeutics windows could be defined: one for the reperfusion (between 6 and 8 hours), another for the survival of neurons that are within the penumbra area (between 24 hour and 17 days) and a window for the neurofunctional recovery that extends itself to at least three months after a stroke.

[The evaluation of patients with ischemic cerebral lesions by CT, SPECT and qEEG in acute, subacute and chronic phases]. / Evalución mediante TC, SPECT y qEEG de pacientes con lesiones isquémicas cerebrales durante las fases aguda, subaguda y crónica.

INTRODUCTION: SPECT, EEG AND CT scan offer information with several pathophysiologic meanings. Their results vary with time and according to the vascular affected territory. OBJECTIVE: We wanted to study how the sensibility varies and the relationship with the clinic of SPECT, qEEG and CT scan in the acute, subacute and chronic stages and according to the vascular affected territory. We also wanted to analyze the several pathophysiologic aspects of the cerebral ischemia. METHODS: Thirty-six patients with symptoms of hemispheric stroke were evaluated with CT scan, qEEG, SPECT99mTc-HMPAO during the acute (0-5 days), subacute (0-15 days) and chronic (16 days to 1 year) stages. RESULTS: The decrease of ipsilateral CBF depend on the time (p = 0.0061), being not very frequent during the two first weeks. The qEEG was the most sensitive study in the first phase, its sensibility did not depend on the vascular affected territory and was dependent on the time (p = 0.0011), diminishing in the chronic phase. The slow activity was habitually ipsilateral. The CT scan was the less sensitive study. CONCLUSION: After 24 hours and until the second week, there is habitually an increase of the ipsilateral rCBF. The luxury perfusion could explain the fogging effect in the CT scan. The slow activity of the qEEG represents the alteration of the oxygen metabolism. The interpretation of the variation of the CBF and the qEEG allow us to define oligemia of the ischemia and between reactive hyperemia and the increase of CBF due to the necrotic tissue.

Evaluación mediante TC, SPECT y qEEG de pacientes con lesiones isquémicas cerebrales durante las fases aguda, subaguda y crónica / Evaluation of patients with ischemic cerebral lesions using TC, SPECT and qEEG during acute, subacute and chronic phases

Introducci›n. La SPECT, el EEG y la TC brindan informaci›n con diferente significado fisiopatol›gico; sus resultados var­an en el tiempo y segœn el territorio vascular afectado. Objetivos. En este estudio nos propusimos estudiar c›mo var­a la sensibilidad y la relaci›n con la cl­nica de la SPECT, el qEEG y la TC en las etapas aguda, subaguda y cr›nica, segœn el territorio vascular afectado. Asimismo, analizamos diferentes aspectos fisiopatol›gicos de las ECV isqu micas. M todos. Se realiz› un estudio con TC, qEEG, SPECT 99mTc-HMPAO durante las etapas aguda (0-5 d­as), subaguda (6-15 d­as) y cr›nica (de 16 d­as a 1 a o) a 36 pacientes. Resultados. La disminuci›n ipsilaeral del FSC dependi› del tiempo (p=0,0061), siendo poco frecuente durante las dos primeras semanas. El qEEG fue el estudio mÿs sensible en la primera fase, su sensibilidad no estuvo relacionada con el territorio vascular afectado y si dependi› del tiempo (p=0,0011), disminuyendo en la fase cr›nica. La actividad lenta habitualmente fu ipsilateral. La TC de crÿneo result› ser el estudio menos sensible. Conclusiones. Despu s de las 24 horas y hasta la segunda semana, habitualmente se produce un aumento del FSCr ipsilateral. la perfusi›n de lujo podr­a explicar el efecto fogging en la TC simple de crÿneo. La actividad lenta del qEEG representa la alteraci›n del metabolismo de ox­geno. La interpretaci›n de la variaci›n del FSC y del qEEG permite delimitar entre la perfusi›n de miseria de tipo oligo mica de la isqu mica, as­ como la hiperemia reactiva del aumento del FSC debido a la necrosis tisular

[The HIV/AIDS work of Mexican nongovernmental organizations]. / El trabajo en VIH/SIDA de las organizaciones no gubernamentales mexicanas.

In Mexico, non-governmental organizations (NGO) addressing specifically HIV/AIDS issues originated in 1983, with the activities of homosexual groups from Mexico City, Guadalajara and Tijuana. The creation of the AIDS National Prevention and Control Council (CONASIDA) and the advent of Mexicans Against AIDS, Confederation of NGO, paved the way towards a solid organization of groups created in recent years. This essay addresses the obstacles, accomplishments and advancements that NGO working on AIDS have experienced in their struggle against the AIDS epidemic in Mexico. The circumstances that have prevented collaborative work of NGO are analyzed, and finally, an optimistic vision of harmonic collaborative work among Mexican NGO is presented.