Feasibility of Using a Novel 2.45 GHz Double Short Distance Slot Coaxial Antenna for Minimally Invasive Cancer Breast Microwave Ablation Therapy: Computational Model, Phantom, and In Vivo Swine Experimentation.

Microwave ablation (MWA) by using coaxial antennas is a promising alternative for breast cancer treatment. A double short distance slot coaxial antenna as a newly optimized applicator for minimally invasive treatment of breast cancer is proposed. To validate and to analyze the feasibility of using this method in clinical treatment, a computational model, phantom, and breast swine in vivo experimentation were carried out, by using four microwave powers (50 W, 30 W, 20 W, and 10 W). The finite element method (FEM) was used to develop the computational model. Phantom experimentation was carried out in breast phantom. The in vivo experimentation was carried out in a 90 kg swine sow. Tissue damage was estimated by comparing control and treated micrographs of the porcine mammary gland samples. The coaxial slot antenna was inserted in swine breast glands by using image-guided ultrasound. In all cases, modeling, in vivo and phantom experimentation, and ablation temperatures (above 60°C) were reached. The in vivo experiments suggest that this new MWA applicator could be successfully used to eliminate precise and small areas of tissue (around 20-30 mm2). By modulating the power and time applied, it may be possible to increase/decrease the ablation area.

Tracheal and bronchial polymeric immunoglobulin secretory immune system (PISIS) development in a porcine model.

Polymeric immunoglobulins (pIgs) mucosal secretion is mediated by the pIg secretory immune system (PISIS), which is composed of J-chain (JC) and antibody (IgM/IgA) producing cells (JC-AbPC), pIg receptor (pIgR) epithelial cell expression and the efficient release of secretory Igs (SIgs) to the mucosal lumen. A poor development or disturbances in this system may cause higher infection susceptibility, as observed in young and elderly people. In spite of this system's importance, few detailed studies regarding its development have been described in the lower respiratory tract of humans. Because the porcine model has been reported as an option for translational medicine to humans, we studied the tracheal and bronchial PISIS development in healthy, non-vaccinated, SPF, miniature Vietnamese pigs from birth to adulthood using immunohistochemistry and ELISAs. Our results demonstrated that pIgR was present at birth, and its expression increased with age. In contrast, JC-AbPC were low in neonatal pigs; however, colostrum was a source of IgM, SIgA, total IgA and IgG in respiratory secretions (trachea and bronchoalveolar lavages, nasal secretion and saliva) in piglets. JC-AbPC steadily increased in post-weaned, young and adult pigs, correlating with considerable increases in secretory and total Igs in the trachea and bronchi. These data suggest a compensatory role of maternal Igs at the respiratory mucosa in the absence of a structured PISIS before weaning. Furthermore, monomeric Igs (IgG and IgA) may also play an important role in respiratory protection and deserves a more thorough study.

Partial protection and abomasal cytokine expression in sheep experimentally infected with Haemonchus contortus and pre-treated with Taenia hydatigena vesicular concentrate.

The abomasal expression of IL-2, IL-4, IL-6, IL-10 and IFNγ in lambs experimentally infected with Haemonchus contortus and its relationship to protection induced by a Taenia hydatigena larvae vesicular concentrate (ThLVC) were evaluated. The lambs that were only infected with H. contortus larvae showed a worm burden greater (p<0.05) than the lambs that received ThLVC prior to infection. Moreover, the lambs that received ThLVC showed a greater (p<0.05) number of blood eosinophils than the lambs that did not receive the ThLVC. In general, the lambs that received ThLVC prior to infection had a greater amount of eosinophils and mast cells and higher in situ expression of IFNγ, IL-2, IL-4, IL-6 and IL-10 in the abomasal wall than the lambs that were infected with H. contortus only or that received ThLVC (p<0.05) only. A higher expression of IL-2 and IFNγ in the submucosa compared to the abomasal mucosa and a higher expression of IL-4 in the abomasal mucosa compared to the submucosa was observed (p<0.05). These results suggest that there is a Th1 type response in the abomasal submucosa and a Th2 type response in in the abomasal mucosa. The amount of eosinophils and mast cells and the in situ expression of IFNγ, IL-2, IL-4 and IL-6 in the abomasal walls were negatively correlated with the worm burden (p<0.05). These results suggest that ThLVC is a non-specific immune stimulator for the abomasal immune response, and it is likely that the protection observed is the result of this effect.

Effects of Vitamin D Supplementation during the Induction and Progression of Osteoarthritis in a Rat Model.

Epidemiological studies correlate low levels of vitamin D with the osteoarthritis (OA) progression. Cytokines and metalloproteases play a major role in OA promoting the inflammation and degradation of the cartilage and can be induced through the Toll-like receptor (TLR) pathway. The aim of this study was to evaluate the protective effect of vitamin D supplementation on the development of osteoarthritis (OA) through examining the genetic regulation of TLRs, cytokines, and metalloproteases in chondrocytes as well as the wideness of cartilage in rats with OA. Our results demonstrate that the signaling through TLR-4 is a proinflammatory mechanism in osteoarthritis that drives the upregulation of MMP-3, IL-1ß, and TNF-α gene expression, leading to cartilage degradation and inflammation. Vitamin D supplementation had a protective effect during the onset but not during the chronic stage of OA in the rat model.

Cell death of chondrocytes is a combination between apoptosis and autophagy during the pathogenesis of Osteoarthritis within an experimental model.

The death of chondrocytes and the loss of extracellular matrix are the central features in cartilage degeneration during Osteoarthritis (OA) pathogenesis. The mechanism by which chondrocytes are removed in OA cartilage are still not totally defined, although previous reports support the presence of apoptotic as well as non apoptotic signals. In addition, in 2004 Roach and co-workers suggested the term "Chondroptosis" to design the type of cell death present in articular cartilage, which include the presence of some apoptotic and autophagic processes. To identify the mechanisms, as well as the chronology by which chondrocytes are eliminated during OA pathogenesis, we decided to evaluate apoptosis (by active caspase 3 and TUNEL signal) and autophagy (by LC3II molecule and cytoplasmic vacuolization) using Immunohistochemistry and Western blot techniques in an animal OA model. During OA pathogenesis, chondrocytes exhibit modifications in their death process in each zone of the cartilage. At early stages of OA, the death of chondrocytes starts with apoptosis in the superficial and part of the middle zones of the cartilage, probably as a consequence of a constant mechanical damage in the joint. As the degenerative process progresses, high incidence of active caspase 3 as well as LC3II expression are observed in the same cell, which indicate a combination of both death processes. In contrast, in the deep zone, due the abnormal subchondral bone ossification during the OA pathogenesis, apoptosis is the only mechanism observed.

Intranasal immunization using biphasic lipid vesicles as delivery systems for OmlA bacterial protein antigen and CpG oligonucleotides adjuvant in a mouse model.

The nasal mucosa is an important arm of the mucosal system since it is often the first point of contact for inhaled antigens. The ineffectiveness of the simple delivery of soluble antigens to mucosal membranes for immunization has stimulated extensive studies in appropriate delivery systems and adjuvants. We have evaluated biphasic lipid vesicles as a novel intranasal (i.n.) delivery system (designated as vaccine targeting adjuvant, VTA) containing bacterial antigens and CpG oligodeoxynucleotides (ODNs). Results show that administration of antigen and CpG ODNs in biphasic lipid vesicles resulted in greater induction of IgA levels in serum (P< 0.05) and mucosal antibody responses such as IgA in nasal secretions and lung (P< 0.01) after immunization with a combined subcutaneous (s.c.)/i.n. as compared to s.c./s.c. approach. Based on antibody responses, VTA formulations were found to be suitable as delivery systems for antigens and CpG ODNs by the intranasal route, resulting in a Th2-type of immune response, characterized by IgG1 and IL-4 production at the systemic level.

Development of intraepithelial cells in the porcine small intestine.

The number, phenotype, localisation and development of intraepithelial lymphocytes (IEL) from duodenum (Du) and ileum (Il) were studied by immunohistochemistry (IHC) and light and electron microscopy in unweaned (0-7 weeks old) and six months-old pigs. Developmental changes at birth showed that 38% of the total lymphocytes in the villi were IEL, mainly of the CD2+CD4-CD8- double negative (DN) phenotype. That proportion rose to over 50% at week 5 after birth, resembling adult proportion, although still with fewer cells than in adult pigs. CD4+ cells appeared relatively early in life although they were confined to the lamina propria (LP) and CD8+ cells were found only in low numbers. In the villi of adult animals, almost half of the total number of lymphocytes were IEL (49% Du, 52% Il). Over half of these IEL (52% Du, 53% Il) showed the CD2+CD4-CD8+ phenotype and were localized at the epithelium's basement membrane. Numerous (43% Du, 42% Il) DN IEL were found grouped at the enterocyte nucleus level and relatively few (5% in Du and Il) granular IEL were found apically in the epithelium. These proportions were homogeneously maintained along the villi's tip, middle and bottom, suggesting that the IEL may have their origin in the LP. Therefore, the IEL compartment in the porcine intestine develops slowly with age and is actually composed by a heterogeneous population of cells (null, DN and CD8+). These results may explain the increased susceptibility of young animals to disease during the lactation period and should be taken into account when functional studies are carried out with IEL. The quantitative results of this paper established a model for studies on the effect of age, diet, normal flora, infection and oral immunization on the IEL of the gut.

Caesarean sections in Mexico: are there too many?

This paper seeks to quantify the magnitude of caesarean sections in Mexican public health-care institutions in recent years, to characterize the evolution of caesarean section rates (CSR) during the last decade, and to estimate the possible economic cost caused by the excess of caesareans performed in these institutions. The study is based on data obtained from the health sector, both for Mexico in the 5-year period 1993-97 and for the Mexican State of Jalisco between 1983 and 1998. Linear regression analysis was used to evaluate time series, and "excess of caesareans" was considered the number of caesarean deliveries performed above the admissible 15% CSR. The results reflect that on the national level, more than one-quarter of the deliveries handled by public institutions ended in caesarean section for each analyzed year, and if the deliveries performed in private institutions are included, the national rate is around 30%. A marked increase in CSR can be observed in Jalisco between 1983 and 1998 (almost 50%); and the cost for the nation of this CSR excess in financial terms is highly significant: several millions of dollars--obtained from public funds--are spent annually and unnecessarily by health services. The findings suggest that the increase in CSR is a public health problem that has not been satisfactorily faced by the health sector authorities. Many unnecessary caesareans would undoubtedly be avoided if the policies of these public health-care institutions were to consider, as a priority, both the known higher risk implicit in a caesarean for the health of the mother and child, and the economic impact on the country and its health institutions of the excessive number of caesareans performed yearly.

Regulation of mucosal immune responses in effector sites.

In human disease and rodent models, immune responses in the intestinal mucosa can be damaging. Damage is characterised by villus atrophy, crypt hyperplasia and reduced ability to digest and absorb nutrients. In normal individuals active responses to harmless environmental antigens associated with food and commensal bacteria are controlled by the development of immunological tolerance. Similar pathological changes occur in piglets weaned early from their mothers. Active immune responses to food antigens are observed in these piglets, and we and others have hypothesised that the changes occur as a result of transient allergic immune responses to novel food or bacteria antigens. The normal mechanism for producing tolerance to food antigens may operate at induction (Peyer's patches and mesenteric lymph nodes) or at the effector stage (intestinal lamina propria). In our piglet studies immunological tolerance occurs despite the initial active response. Together with evidence from rodents, this observation suggests that active responses are likely to be controlled at the effector stage, within the intestinal lamina propria. Support for this mechanism comes from the observation that human and pig intestinal T-cells are susceptible to apoptosis, and that this process is accelerated by antigen. We suggest that the role of the normal mature intestinal lamina propria is a balance between immunological effector and regulatory function. In neonatal animals this balance develops slowly and is dependant on contact with antigen. Immunological insults such as weaning may tip the balance of the developing mucosal immune system into excessive effector or regulatory function resulting in transient or chronic allergy or disease susceptibility.

[Effects of an educational intervention on plasma levels of LDL cholesterol in type 2 diabetics]. / Efectos de una intervención educativa sobre los niveles plasmáticos de LDL-colesterol en diabéticos tipo 2.

OBJECTIVE: To prove the benefit of an educational intervention for controlling LDL cholesterol levels in LDL cholesterol. MATERIAL AND METHODS: A quasi-experimental study was conducted; diabetic patients were randomly allocated to an experimental and a control group. The experimental group consisted of 25 patients and the control group of 24 patients. The educational intervention was organized through a reflection-action process. LDL cholesterol levels were measured at baseline and monthly during the nine months of the study. The groups were controlled for age and sex. Statistical analysis included Wilcoxon's test for ordinal variables. RESULTS: The intervention group had a mean value of LDL cholesterol of 148.4 +/- 21.3, compared to 185 +/- 24.1 in the control group (p < or = 0.05). CONCLUSIONS: The participative educational intervention contributed to improving the levels of LDL cholesterol, by promoting a lifestyle change in type-2 diabetic patients.

[Experience with montelukast, a leukotriene receptor antagonist, in pediatric patients with asthma]. / Experiencia con montelukast, un antagonista de los receptores de leucotrienos, en pacientes pediátricos con asma.

BACKGROUND: Montelukast is a specific antagonist of leukotrienes' receptors and constitutes a therapeutic option in controlling asthma. OBJECTIVES: To evaluate efficacy of montelukast in patients with persistent light asthma, persistent moderate asthma and exercise-induced asthma; to try to reduce or to eliminate doses of inhaled steroid; to reduce the use of short-action beta agonists and to assess its tolerability in pediatric patients. MATERIAL AND METHOD: 40 patients were studied, 17 female, with an age range from 4 to 11 years and a mean of 7 years. Stratification was made by GINA-established parameters. RESULTS: Steroid dose could be reduced in 88%, with definitive suspension in 66% of patients. Moreover, an improvement in reducing asthma stratification and the use of rescue drugs were registered. 62% of patients with exercise-induced asthma improved and there was a good tolerance with the same side effects.

Cloning and analysis of a Trichinella britovi gene encoding a cytoplasmic heat shock protein of 72 kDa.

A gene encoding a protein of 646 amino acid residues with a molecular mass of 71.3 kDa showing homology to the cytoplasmic form of the 70 kDa heat shock protein was cloned and sequenced from the nematode parasite Trichinella britovi (Tb). The gene was expressed in vitro as a protein of 71 kDa that was immunoprecipitated by a Trichinella-infected rabbit serum. Monospecific polyclonal antibodies raised against the recombinant Tb Hsp70 expressed in Escherichia coli, recognized a protein of 70 kDa by Western blot analysis of Tb soluble antigen (muscular stage). Tb Hsp70 was located in the nuclei of the muscle larvae as determined by the indirect immunofluorescent pattern on cross-sections of the worm. The expression of this protein was not detected in adult worm nuclei suggesting a differential expression of Hsp70 between the 2 stages of Trichinella.

Using logistic regression to describe the length of breastfeeding: a study in Guadalajara, Mexico.

This study seeks, through a logistic regression model, to describe the pattern of breastfeeding duration in Guadalajara, Mexico, during 1993. A multistage random sample of children under 1 year of age (n = 1036) was studied; observational data regarding breastfeeding duration, obtained through a "status quo" procedure, were compared with prevalence rates obtained from the logistic regression model. Modeling the duration of breastfeeding during the first year of life rather than only analyzing observational data helps researchers to understand this process in a dynamic and quantitative way. For example, uncommon indicators of breastfeeding were derived from the model. These indicators are impossible to obtain from observational data. The prevalence curve estimated through the logistic model was adequately fitted to observed data: there were no significant differences between the number or distribution of breastfed infants observed and those predicted by the model. Moreover, the model revealed that less than 40% of the children were breastfed in the fourth month of life; the median age for weaning was 39.3 days; 55% of the potential breastfeeding in the first 4 months did not occur; and the greatest abandonment of breastfeeding in the first 4 months was observed in the first 60 days. Thus, logistic regression seems a suitable option to construct a population-based model that describes breastfeeding duration during the first year of life. The indicators derived from the model offer health care providers valuable information for developing programs that promote breastfeeding.

PIP: This study describes the pattern of breast-feeding duration in Guadalajara, Mexico, in 1993, using a logistic regression model. A multistage random sample of children under 1 year of age (n = 1036) was studied; observational data regarding breast-feeding duration, obtained through a "status quo" procedure, were compared with prevalence rates obtained from the logistic regression model. Modeling the duration of breast-feeding during the first year of life rather than only analyzing observational data helps researchers to understand this process in a dynamic and quantitative way. For example, uncommon indicators of breast-feeding were derived from the model. These indicators are impossible to obtain from observational data. The prevalence curve estimated through the logistic model was adequately fitted to observe data: there were no significant differences between the number or distribution of breast-fed infants observed and those predicted by the model. Moreover, the model revealed that less than 40% of the children were breast-fed in the fourth month of life. The median age for weaning was 39.3 days and about 55% of potential breast-feeding in the first 4 months did not occur. Lastly, the highest abandonment of breast-feeding in the first 4 months was observed in the first 60 days. Thus, logistic regression seems a suitable option to construct a population-based model that describes breast-feeding duration during the first year of life.

Intragastric immunization of rats with Entamoeba histolytica trophozoites induces cecal mucosal IgE, eosinophilic infiltration, and type I hypersensitivity.

We have investigated the role of IgE in the local immunity of intestinal amebiasis, a parasitic infection known to induce specific antibody-forming cells (AFC) and IgA antibodies in rodents and humans. We found that intragastric immunization of rats with glutaraldehyde-fixed Entamoeba histolytica trophozoites significantly increased antiameba AFC in the Peyer's patches and spleen and that the lamina propria of the cecum from immunized animals was infiltrated by eosinophils armed with IgE antibodies. Morphometric analysis showed that IgE-containing cells and eosinophils were nearly three times more abundant in the cecum of immunized rats. Antigenic challenge with amebal lysates provoked an increase in the short-circuit current and in the transepithelial potential difference in Ussing-chambered cecum preparations from immunized rats. Although eosinophilia and the increase of IgE are common consequences of infection by parasitic worms, our results indicate that local immunity in intestinal amebiasis also involves IgE deposition, eosinophil infiltration, and type I hypersensitivity, which may explain some symptoms of amebic dysentery such as colic, abdominal tension, tenesmus, and bloody stools.

[The study of the smoking-related mortality in Jalisco, Mexico]. / Estudio de la mortalidad atribuible al tabaquismo en Jalisco, México.

BACKGROUND: In recent years, tobacco consumption its associated health problems have increased in Mexico. This study aims to describe the effects of tobacco use on mortality in the State of Jalisco, Mexico, in 1990. METHODS: 22 smoking-related diseases, for which there are estimates of relative risks of death were selected; smoking-attributable mortality fractions for each disease per sex, were calculated. This made it possible to estimate smoking-attributable mortality rates, years of potential life lost (YPLL), due to tobacco uses and life expectancy at birth (LEB), excluding mortality due to smoking. RESULTS: Smoking-attributable deaths represent 8.7% of all registered deaths in 1990. Ab high proportion of theses deaths belonged to ancient people. The smoking-attributable rate was 4.91 per 10,000 inhabitans (6.33 for males and 3.58 for females); YPLL rates, due to tobacco use was 2.98 per 1,000 inhabitans younger than 65 years (3.99 for men and 2.02 for women). CONCLUSIONS: Smoking-attributable mortality PYLL rates were higher than those rates observed for infectious and parasitical diseases, and for endocrinal and digestive system disorders. Due to tobacco use, men die more frequently and at a younger age than women. In the absence of tobacco use, the LEB increase would be notorious.

[Risk factors for unfavorable birth weight in areas surrounding Guadalajara, Mexico]. / Factores de riesgo del peso al nacer desfavorable en áreas periféricas de Guadalajara, México.

This study seeks to identify the incidence of unfavorable birth weight (UBW) -< 3000 grams, the factors associated with this condition, and the probability that a child has an UBW in the presence or absence of identified risk factors, in Tlaquepaque and Tonal , outlying areas of Greater Metropolitan Guadalajara, Mexico. A sample of live-born infants in 1991, children of mothers covered by the Mexican Institute of Social Security were selected from the study area; through multistage probabilistic sampling, random selection was made of Family Medical Units within the study areas, and of physicians' offices within those selected units; finally, all the liveborn infants in 1991 from these selected physicians' offices were studied: a total of 141 newborns were studied Mothers of the newborns chosen were interviewed; a questionnaire with different biomedical, socioeconomic, and demographic items was applied by social workers specially trained for the purpose. Logistic regression models were used lo estimate odds ratios (OR), with 95% confidence intervals (CI). The probability that a child would have UBW in the presence or absence of identified risk factors were also calculated. The results show that 22% of the infants studied were born weighing less than 3000 grams; four risk factors were statistically associated with UBW: mother's age of 35 or older (OR=18.47, CL 1.86-83.54); mother worked outside the home (OR= 3.14, C1:1.15-8.59); mother's pre-pregnancy low weight (OR= 5.04, CL1.04-24.47); and late detection of pregnancy (OR=2.64, CI: 1.02-6.84). In the presence of all the risk factors identified, there is a very high probability (0.97) that a child be born with birthweight less than 3000 g, and in the absence of these factors the probability is reduced substantially (0.04). The findings indicate the magnitude of the problem studied, but also the possibility of health services acting in a timely fashion, since the identified risk factors make it possible lo predict, with relative certainty, the birth of a child weighing less than 3000 g.

Effect of early weaning on the development of immune cells in the pig small intestine.

The controlled effects of age and weaning on the numbers of CD2+ T cells, subsets (CD4+, CD8+), accessory cells (macrophage/granulocyte) and cells expressing MHC class II (DQw) and IL-2R in the piglet intestine was investigated. At birth low numbers of CD2+CD4-CD8- cells were the only demonstrable T cells in the intestine. Monocyte/granulocyte and MHC class II+ cells were also detected in low numbers and IL-2R+ cells were proportionally quite numerous. All those cell populations, except the IL-2R+ cells, increased thereafter and peaked at Week 7 when the numbers of cells were comparable with those of adult animals. CD4+ cells increased dramatically after Week 1. In contrast, CD8+ remained scarce until after 5-7 weeks of age in unweaned animals. Four days after weaning at 3 weeks old, there were increases in CD2+ (P < 0.001) and macrophage/granulocyte (P < 0.01) cells in proximal small intestinal villi and in CD2+ cells only (P < 0.01) in crypts. No significant changes in cell numbers were demonstrated in the distal small intestine.

[Maternal factors associated with the duration of breast-feeding in peripheral areas of Guadalajara, Mexico]. / Factores maternos asociados a la duración de la lactancia en áreas periféricas de Guadalajara, México.

The aim of the present study is to determine the duration of breast-feeding by mothers covered by the Mexican Social Security Institute and living in Tlaquepaque and Tonalá, outlying areas of the city of Guadalajara, Mexico; to identify possible maternal factors associated with early weaning; and to consider the social importance of this phenomenon. A sample of live-born infants and their mothers were selected from the study area. The children had reached at least one month of age between May 1990 and April 1991. Through multistage probabilistic sampling, random selection was made of primary health care units within the study areas, of family physicians' offices within those units, and finally, of all children meeting the study criteria in each of those offices. After visits to 166 dwellings, 141 mothers were interviewed, or 91% of the projected sample size (155). A 33-item questionnaire was prepared for the interviews. The interviewers were social workers trained to do this work, which they carried out between June and July 1991. Logistic regression models were used to estimate the relative risk (RR) associated with each variable and the probability that the infant was weaned early because of the presence or absence of certain variables. To ensure valid results, several regression models were developed with a view to selecting the one that best fit the data. The population attributable risk (PAR) was also calculated. The findings indicate that few mothers breast-feed their children in these areas, since 34.8% of the children were breast-fed for less than one month. Three maternal risk factors were statistically associated with early weaning (p < 0.05): maternal age under 20 years (RR = 3.75; CI 95%: 1.53-9.19); single marital status (RR = 2.88; CI 95%: 1.08-7.69); and social class, i.e., the mother's belonging to a "non-worker" social group (RR = 2.72; CI 95%: 1.17-6.28). The probability of an infant being breast-fed for less than one month was 0.84 when the three maternal risk factors were present, and 0.15 when they were absent. The high estimated PAR reflects the high proportion of mothers who were under the age of 20 or did not belong to the working class. The results underscore the importance of reducing the effect of these risk factors so that breast-feeding can become more widely practiced in the population studied.