NKG2C gene deletion in the Mexican population and lack of association to respiratory viral infections.

Expansion of a natural killer (NK) cell population that expresses NKG2C has been associated with cytomegalovirus and other viral infections. It has been suggested that this cell population may play a role in infection control. Deletion of the NKG2C gene (homozygous or heterozygous) has been reported with high prevalence in European and Asian populations. However, the effect of NKG2C genotype on NK cell responses to infection remains poorly defined. We determined the prevalence of the NKG2C deletion in a Mexican population (n = 300) and in a group of patients (n = 131) to assess whether NKG2C genotype affects the incidence of symptomatic viral infections caused by influenza or respiratory syncytial virus. The frequency of the NKG2C deletion haplotype in Mexican mestizos was significantly lower (10.3%) than that reported in other populations (17.5-21.9%). No difference in the prevalence of NKG2C deletion was observed in subjects with viral infections compared with the reference population. In addition, no differences in clinical characteristics and infection outcome were observed between patients with and without the NKG2C gene deletion. Our results indicate that copy number variation in the NKG2C gene has no impact on the severity of respiratory viral infections.

Lipid droplet analysis using in vitro bovine oocytes and embryos.

The aim of this study was to quantify the content of lipid droplets in bovine oocytes and embryos from Bos indicus (Bi), Bos taurus (Bt) and Bos indicus × Bos taurus (Bi × Bt). Oocytes were aspirated post-mortem and subjected to in vitro maturation, in vitro fertilization and in vitro development; the medium employed at each stage (TCM-199, TALP, SOF) was supplemented with (i) serum replacement (SR), (ii) foetal calf serum (FCS) or (iii) oestrous cow serum (ECS). The structure and distribution of the lipid droplets were established using electron microscopy, but were quantified using an optical microscope on semi-fine toluidine blue-stained sections. The highest percentage of embryos corresponded to those produced with FCS and ECS, which differed from embryos generated with SR (p < 0.05). The highest percentage of morulae and the lowest percentage of blastocysts were obtained with the SR supplement (p < 0.05). The oocytes cultured in FCS demonstrated a higher number of lipid droplets compared to those cultured in SR and ECS (p < 0.05). Less accumulation of lipids was observed in embryos supplemented with SR. The lowest and highest numbers of lipid droplets in oocytes corresponded to the Bi and Bt strain, respectively. The lowest amount of lipid droplets in embryos was observed in Bi (p < 0.05). In conclusion, supplementation of the in vitro development culture medium (synthetic oviduct fluid) with a synthetic substitute serum produced similar results in terms of embryo development compared to those obtained with FCS, but a decreased degree of lipid droplet accumulation was observed in the in vitro-cultured embryos.

Ejaculate and type of freezing extender affect rates of fertilization of horse oocytes in vitro.

In vitro fertilization (IVF) was performed on in vitro-matured equine oocytes in three experiments. Frozen-thawed sperm were prepared using swim-up separation and heparin treatment. In Experiment 1, fertilization was achieved with sperm from only one frozen ejaculate of four obtained from the same stallion. Within this ejaculate, fertilization rates were higher with fresh media, as compared to media held for 6-8 days before use (39.6% versus 7.3%, respectively; P<0.001). The type of bovine serum albumin used affected fertilization rates (4% versus 39.6%; P<0.001). To determine if IVF rates were influenced by factors associated with the freezing process (Experiment 2), a single ejaculate from a second stallion was frozen using eight variations in timing of steps in the freezing protocol. There were no differences among treatments in fertilization rates (range, 0-3%). In Experiment 3, fertilization rates of semen frozen in an extender containing 21.5% egg yolk were lower than fertilization rates of semen from the same ejaculate but frozen with a 3% egg-yolk extender (0% versus 15%, respectively; P<0.01). We inferred that rates of equine IVF with frozen-thawed sperm were influenced by ejaculate, the composition and age of the media used, and freezing extender. To our knowledge, this is the first report of ejaculate or extender differences affecting in vitro fertilization in this species. These factors may help to explain the great variability in fertilization rates reported with equine IVF, both among and within laboratories.

Evaluation of the enhanced oral effect of omapatrilat-monolein nanoparticles prepared by the emulsification-diffusion method.

In the present study, the emulsification-diffusion method was optimized in order to obtain omapatrilat/monolein-nanoparticles (omapatrilat/MO-nanoparticles). The antihypertensive effect of omapatrilat/MO-nanoparticles in spontaneously hypertensive rats (SHR) after oral administration was evaluated. The results indicated that the variables involved in the process did not have an influence on particle size, and that the former is directly determined by the amphiphilic properties of MO. When SHR were orally treated with omapatrilat/MO-nanoparticles, blood pressure was significantly reduced and completely normalized after three days. This effect was markedly higher than that observed with omapatrilat suspensions. The effect of omapatrilat/MO-nanoparticles can be attributed to: (i) The molecular dispersion of the drug into the lipophilic domain of monolein's bicontinuous phase; (ii) the adhesive properties of the nanodispersion on the gastrointestinal mucosa; (iii) the high surface area of the dispersion; (iv) the intraluminal interaction between MO, the mixed micelles arising from the digestive process, and omapatrilat; and (v) the well-known absorption-promoting properties of lipids, and in particular, of MO. MO-nanoparticles can be an interesting system to increase the oral bioavailability of drugs.

Pronuclear formation by ICSI using chemically activated ovine oocytes and zona pellucida bound sperm.

BACKGROUND: In order to improve ICSI, appropiate sperm selection and oocyte activation is necessary. The objective of the present study was to determine the efficiency of fertilization using ICSI with chemically activated ovine oocytes and sperm selected by swim up (SU) or swim up + zona pellucida (SU + ZP) binding. RESULTS: Experiment 1, 4-20 replicates with total 821 in vitro matured oocytes were chemically activated with ethanol, calcium ionophore or ionomycin, to determine oocyte activation (precense of one PN). Treatments showed similar results (54, 47, 42 %, respectively) but statistically differents (P < 0.05) than mechanical activated oocytes in sham, ICSI and sham injection (13, 25, 32 %, respectively) (10-17 replicates; n = 429). Experiment 2: Twelve ejaculates and 28 straws of semen were used (11-19 replicates). Sperm were selected by SU in BSA-TCM 199-H medium. A total of 2,294 fresh sperm and 2,760 from frozen-thawed semen were analyzed after SU or SU + ZP binding. Fresh sperm selected by SU showed acrosome reaction (AR) of 59 %, the sperm selected by SU + ZP binding increased AR to 91 %. In comparison, the AR of frozen-thawed sperm using SU or SU + ZP binding was 77 and 86 %, respectively (P < 0.05). Experiment 3: fertilization in 200 mechanical activativated oocytes (17 replicates) was 4 %, but fertilization increased in ethanol activated oocytes after ICSI (12-28 %) (5-6 replicates). When fresh sperm only selected by SU were injected to 123 oocytes, a fertilization rate (28 %) was achieved; in sperm selected by SU + ZP was 25 % (73 oocytes). In comparison, in frozen-thawed sperm selected by SU, fertilization was 13 % (70 oocytes), whereas sperm from SU + ZP binding displayed 12 % (51 oocytes) (P > 0.05). CONCLUSIONS: Chemical activation induces higher ovine oocyte activation than mechanical activation. Ethanol slightly displays higher oocyte activation than calcium ionophore and ionomicine. Sperm selection with SU + ZP increased AR/A and AR/D rates in comparison with SU in fresh and frozen-thawed sperm. According to this, in terms of fertilization rates, chemical activation after ICSI increased oocyte PN formation compared to mechanical activation. Also, fresh sperm treated with SU and SU + ZP were significantly different than frozen-thawed sperm, but between sperm treatments no significant differences were obtained.

No Evidence of Dengue Virus Infections in Several Species of Bats Captured in Central and Southern Mexico.

Bats are reservoirs for viruses with zoonotic potential in the Americas, and scattered evidence exists suggesting that bats may act as reservoirs for dengue virus (DENV). To explore further the role of bats as part of DENV sylvatic cycles, 240 bats of 18 species were captured in 2 states of Mexico with contrasting ecological characteristics but concurrent DENV activity in humans. RT-PCR analysis of RNA extracted from liver or spleen tissue from de bats failed to show evidence for the presence of DENV nucleic acids in these organs. In addition, plasma assayed by plaque reduction neutralization test showed no evidence of neutralizing anti-DENV antibodies. These results suggest that American bats may not be reservoirs or amplification host for DENV infection.

Quantitative evaluation of intracellular degradation in Entamoeba invadens.

A quantitative study on digestion of erythrocytes by Entamoeba invadens was attempted. Trophozoites of the IP-1 strain were fed red blood cells for 30 min, and subsequently phagocytosis was stopped by means of osmotic shock; post-phagocytosis incubations for up to 15 h were made in order to evaluate intracellular digestion, after staining the red blood cells with benzidine. Eighty-two per cent of trophozoites were capable of phagocytosing erythrocytes, containing an average of 5.5 erythrocytes per amoeba. Erythrocyte digestion within amoebae was shown by loss of benzidine-stainable material and proceeded with a first-order kinetics, with a t1/2 approximately 7 h. Within 15 h there were no amoebae containing erythrocytes. The procedure described may be useful for the evaluation of intracellular digestion in other Entamoeba species.

Pathogenic action of Entamoeba invadens: intestinal epithelium invasion by trophozoites in vitro.

Interactions between live Entamoeba invadens trophozoites and guinea-pig caecal explants were studied. A high percentage of amoebae adhering to the apical surface of epithelial cells was observed 10-20 min after infection, but no histopathological changes were observed. After 30 min, mild oedema at the base of the interglandular epithelium and death of some epithelial cells were evident. The epithelial barrier was invaded by amoebae at desquamating zones and phagocytosis of epithelial cells or cellular debris was occasionally observed. Invasion of the mucosa and tissue necrosis became more severe with increased time of incubation. The continuity of epithelial lining was severely compromised after 2 h of infection and erosive lesions were prominent in the mucosa. These results demonstrate that E. invadens is able to invade the intestinal epithelium although it reportedly lacks the powerful cytotoxic and cytolytic elements described for E. histolytica.

[Main sociocultural aspects related to breast feeding in Malinalco, Mexico]. / Principales aspectos socioculturales relacionados con la lactancia en Malinalco, Edo. de Mexico.

The present paper discusses data related to some sociocultural aspects on breast-feeding behavior among a group of women from a rural community in Mexico called Malinalco. A sample of 225 mothers with children aged less than 60 months, was selected. Several home visits were done in order to fill up a questionnaire, as well as to follow direct interviews according to some selected variables to the deepened, such as: schooling, occupation, place of children deliveries, breast-feeding behavior beliefs on breast-feeding abandonment, weaning practices, etc. The results showed that there is no relation between breast-feeding practices, income and school years; nevertheless, there is a certain tendency on early abandonment of breast-feeding in women with higher level of schooling. Some local beliefs about breast-milk production were detected, as well as some remedies to stimulate milk production and to cure certain breast-feeding problems. Data on weaning age and the commonest weaning food products are presented. The importance that cultural dimension has on breast-feeding studies is discussed, as well as the relevance of recognizing "the changes of concepts" within the process of cultural development itself, in order to understand them better and to propose solutions to the generated problems.

[Lactation behavior and delivery care in a group of women from a Mexican rural community]. / Conducta de lactancia y atención del parto en un grupo de mujeres de una comunidad rural Mexicana.

This article presents a brief discussion on the role that "medical practice" plays, related to the type of infant lactation after delivery, and breast-feeding practice during the first months of life. Data on hospital routines and how these predispose artificial feeding practices are seen from a critical angle. The information presented in this paper corresponds to a project carried out in a rural community of the state of México, called Malinalco, where the lactation behavior of 65 women after birth of the child, was followed as of their last period of pregnancy. The main objectives of the study were to determine the relationship between the place of delivery (hospital or home delivery) and the type of lactation practiced by the mothers, as well as to determine the infants nutritional status during their first year of life. Results showed that the greater part of women from the sample were young others (less than 30 years old) with one or two children. As to the place where delivery took place, 72% of the sample were attended by midwives at their own homes, and at last 65% practiced breast feeding exclusively during the first three months. No significant correlation between these two indicators (place of delivery and type of lactation) was found, although a tendency to a more prolonged breast-feeding practice was observed in those women who delivered at home. Problems related to weaning practices were detected, since they start this only with bean broth after five months of life. Finally, information on nutritional status during the first 12 months of life, shows serious nutritional problem after the child's third month of life, since the normality percentage starts decreasing while there occurs a significant increase of 1st an 2nd degree malnutrition.

Cryopreservation of in vitro produced bovine embryos: effects of lipid segregation and post-thaw laser assisted hatching.

The objective was to determine if lipid segregation, with or without post-thaw laser assisted hatching (LAH) of in vitro produced (IVP) bovine embryos, would enhance in vitro survivability and development 24 h post-thaw. On Day 6 of culture (Day 0 = IVF), in vitro produced bovine embryos were divided into three developmental stages: 32-cell (n = 78), compact morula (CM n = 223), and blastocyst (n =56). Embryos within each stage were allocated to the following treatments prior to cryopreservation in 1.5M ethylene glycol: no treatment (Control), 7.5 µg/mL Cytochalasin B for 20 min (CB), or CB with centrifugation (16,000 × g) for 20 min (CBCF). All CB treatments were extended to include embryo freezing. Immediately post-thaw, one-half of the CBCF and Control groups were subjected to zona pellucida drilling (LAH), using the XY Clone® system, creating groups CBCFLAH and LAH, respectively. All thawed embryos were cultured for 24 h and evaluated. No treatment differences were observed for either post-thaw survival or 24 h development. Within the CM stage, CBCFLAH and LAH exhibited a greater number of both total and live cells than Control (total: 69.4, 69.3, 53.0, live: 56.4, 54.7, 39.3 respectively; P < 0.05). In conclusion, LAH post-thaw alone or in combination with CBCF improved embryo viability following cryopreservation.

Population dynamic of algae and bacteria in an oxidation channel.

A study on algae and bacteria population changes, as a function of time, was carried out in a pilot scale oxidation channel bioreactor using a carrousel system. Total Coliforms, Pseudomonas aeruginosa, and Streptococcus faecalis, the most common bacteria found in sewage, Scenedesmus obliquus and Chlorella vulgaris were the microalgae considered in this work. Physicochemical parameters such as COD, BOD, Chlorophyll a, nitrogen, and phosphorous compounds were studied and determined during the experiments. It was demonstrated that the level of wastewater contamination could be predicted based on the bacterial and algae composition. The relationships between the algae and bacteria population, and the variation of these microorganism populations as a measurement of the level of purification were established. The oxidation channel was able to remove a considerable amount of organic matter and pathogenic microorganisms in a relatively short time. The nitrification process could not be measured. The increase in the relative concentration of microalgae contributed toward improving the global efficiency of the system as well as reducing the pathogenic bacteria population.

Ultrasound and endocrine evaluation of the ovarian cycle and early pregnancy in the Sumatran rhinoceros, Dicerorhinus sumatrensis.

Longitudinal ultrasound and endocrine evaluations were conducted in two adult female Sumatran rhinoceroses (Dicerorhinus sumatrensis) over a period of 12-22 months to learn more about their reproductive physiology. Rectal ultrasonography was conducted to monitor ovarian activity. Blood samples were collected and analysed for progesterone and LH, and faecal samples were analysed for progestin metabolites. One female showed cyclic ovarian activity during the study period, whereas the other female showed no evidence of ovarian activity. The cyclic Sumatran rhinoceros appeared to be an induced ovulator, the first of its kind reported within the Perrisodactyla. Ultrasound examinations of the ovaries revealed the formation of anovulatory haemorrhagic follicles when the animal was not mated. These follicles appeared to undergo varied degrees of luteinization that resulted in irregular faecal progestin profiles. When allowed to mate, the female showed a 21 day reproductive cycle that was reflected in both faecal progestin and serum progesterone profiles. The concentration of serum LH was baseline before mating, increased approximately 30-fold within 1-2 h of intromission and returned to baseline within 22 h. Ovulation occurred within 46 h of copulation. The female conceived three times during the study. Pregnancy was detected using ultrasonography 14-16 days after mating, and the concentration of both serum progesterone and faecal progestins remained high. Early embryogenesis appeared to be similar to that in horses. However, each pregnancy terminated unexpectedly within the first 3 months of gestation. This study demonstrates the important role that basic research and reproductive technology can play in developing a natural breeding programme for an endangered animal in captivity.

[Breast feeding and child care: a case study of 2 rural areas of Mexico]. / Lactancia y cuidado de los hijos: estudio de casos en dos zonas rurales de México.

The present research is included in the fields of public health, social sciences and gender studies. Its objective is to provide insight into the nursing behaviour of two groups of mothers, their domestic and extra-domestic child care arrangements and their attitudes towards breast-feeding. Thirty-five mothers were selected in Malinalco, Mexico, and 35 in the Sierra de Juárez, Oaxaca. Each mother had at least two children and one of them under three years of age. The study was exploratory in its initial phase, subsequently cross-sectional, comparative and prospective. It constitutes a foundation for longitudinal case studies. A pre-coded questionnaire, including the following issues, was administered: family composition; maternal schooling; maternal employment; nursing behaviour with the last child; child care and attitudes towards breast-feeding. The main information regarding 33 mothers in Malinalco and 31 in Oaxaca revealed that in both areas mothers decided how to feed their children during the first days; during the first month, 55 per cent of mothers in Malinalco breast-fed their child, while approximately 90 per cent did so in Oaxaca. The majority of women worked outside home and resorted to extra-domestic arrangements for child care. No relation was found between the feeding method chosen with the last child and maternal employment. About 90 per cent of women in both areas were "happy" to have been born females and breast-feeding was considered a "must". Seventy five per cent of mothers would not allow other women to breast feed their child, even though they were aware that maternal milk is the best.(ABSTRACT TRUNCATED AT 250 WORDS)

[The validation of qualitative nutritional indicators: the Guttman Scale vs the customary diet]. / Validación de indicadores cualitativos de alimentación: Escala de Guttman vs dieta habitual.

The purpose of this study was to assess the validity and feasibility of using the Guttman Scale as an indicator of usual dietary intake. Validation was done by comparing the results of dietary intake of a population obtained by using the Guttman Scale with a well-known method for evaluating dietary intake: the dietary history (one week). The study was done in seven communities in the state of Puebla, Mexico. Results from this study showed a weak correlation between the Guttman Scale with socioeconomic status and nutritional status. However, the results obtained with the dietary history method had a significant relationship with socioeconomic status and nutritional status. The conclusions are that the Guttman Scale has limitations when it is used as an alternative to the dietary history method for evaluating the total caloric intake, though it can be useful to determine dietary patterns of the individual.

Neuralgía esencial del trigémino, estudio retrospectivo de 64 casos / Esential trigeminal neuralgia: restrospective study of 64 cases

The Trigeminal Neuralgia, which is a non odontogenic pain, that takes place in the cranial-maxillofacial area, is a situation that the general dentist and tha maxillofacial surgeon, in particular, has to reconize. This study analizes 64 cases treated in period of 6 year. The epidemiologic results show several coincidences with international studies. They also show some characteristics not mentioned on the universal literature revised. The unique objective of this document is to determine the epidemiologics aspects of this desease, with respect to patients that attend spontaneously and/ or are derived from the others Services