The Use of Silica Microparticles to Improve the Efficiency of Optical Hyperthermia (OH).

Although optical hyperthermia could be a promising anticancer therapy, the need for high concentrations of light-absorbing metal nanoparticles and high-intensity lasers, or large exposure times, could discourage its use due to the toxicity that they could imply. In this article, we explore a possible role of silica microparticles that have high biocompatibility and that scatter light, when used in combination with conventional nanoparticles, to reduce those high concentrations of particles and/or those intense laser beams, in order to improve the biocompatibility of the overall procedure. Our underlying hypothesis is that the scattering of light caused by the microparticles would increase the optical density of the irradiated volume due to the production of multiple reflections of the incident light: the nanoparticles present in the same volume would absorb more energy from the laser than without the presence of silica particles, resulting either in higher heat production or in the need for less laser power or absorbing particles for the same required temperature rise. Testing this new optical hyperthermia procedure, based on the use of a mixture of silica and metallic particles, we have measured cell mortality in vitro experiments with murine glioma (CT-2A) and mouse osteoblastic (MC3T3-E1) cell lines. We have used gold nanorods (GNRs) that absorb light with a wavelength of 808 nm, which are conventional in optical hyperthermia, and silica microparticles spheres (hereinafter referred to as SMSs) with a diameter size to scatter the light of this wavelength. The obtained results confirm our initial hypothesis, because a high mortality rate is achieved with reduced concentrations of GNR. We found a difference in mortality between CT2A cancer cells and cells considered non-cancer MC3T3, maintaining the same conditions, which gives indications that this technique possibly improves the efficiency in the cell survival. This might be related with differences in the proliferation rate. Since the experiments were carried out in the 2D dimensions of the Petri dishes, due to sedimentation of the silica particles at the bottom, whilst light scattering is a 3D phenomenon, a large amount of the energy provided by the laser escapes outside the medium. Therefore, better results might be expected when applying this methodology in tissues, which are 3D structures, where the multiple reflections of light we believe will produce higher optical density in comparison to the conventional case of no using scattering particles. Accordingly, further studies deserve to be carried out in this line of work in order to improve the optical hyperthermia technique.

Breast milk excretion Kinetic of b-HCH, pp'DDE and pp'DDT.

Breast milk is considered the most important route in the elimination of deposited organochlorine pesticides in a mother's body. The equilibrium of organochlorine pesticides in the human body considers the elements of internal transport processes, the equilibrium pattern between pesticides and tissue fat contents, and the mobilization of lipids and lipoproteins among body parts. The aim of this study was to determine organochlorine pesticide levels in breast milk samples from the 4th to the 30th day of lactation and the trend in their concentration time so as to forecast the time tendency of residue levels and the pesticide excretion pattern. Milk samples were taken from forty participants and analyzed by GLC-ECD. The organochlorine pesticide residues determined in the breast milk samples during lactation decreased: ß-HCH from 0.095 to 0.066 mg/kg, pp'DDE from 1.807 to 1.423 mg/kg and pp'DDT from 0.528 to 0.405 mg/kg, at the characteristic rate for each compound. The obtained results compared with the calculated fits of forecasts were parallel and did not exhibit significant differences. The newborn baby exposed during lactation had organochlorine pesticide residues whose levels decreased permanently. The levels depended not only on the breast milk nutrition, but also on the total environmental exposures which included air pollution as a significant contamination source.

[Low birth weight is a risk factor for type 1 diabetes]. / El bajo peso al nacer es un factor de riesgo de diabetes mellitus tipo 1.

INTRODUCTION AND AIM: Over recent years, the increasing incidence of type 1 diabetes mellitus (T1DM) has been associated with different factors, particularly increased obesity in childhood. The aim of this study was to find out if there was any relationship between birth weight, body mass index (BMI) increase during the first two 3 years of life, and BMI at diabetes onset with age at diagnosis, in a cohort of children diagnosed with T1DM. MATERIAL AND METHOD: Data from 100 Caucasian children with T1DM of both sexes (57 boys, 43 girls) between 10 months and 16 years of age, mean age 84.45 months (SD; 52.4), were studied. We analysed the following variables: age at diagnosis, gestational age, weight and height at birth, at two years of age and at diabetes diagnosis, expressed as SD scores (SDS). RESULTS: All children were between 38-40 weeks of gestational age. Diabetic patients have lower birth weight (-2.88 ((-0.51)-(-0.066)) and lower BMI at birth compared with healthy children -0.5 ((-0.77)-(-0.23)). Diabetic children have a significant increase in BMI during the first two years of life (4.58 versus 2.17; P<0.001). Children with the lowest BMI at birth (12.77 versus 13.06; P<0.006) are the youngest at onset of the disease. BMI at diagnosis was not related to any of the variables studied. There were no gender differences either. CONCLUSIONS: The low BMI at birth and the later increase in the following years of life seem to be related to intrauterine environment as a risk factor for T1DM.

Effect of medium-chain fatty acid positional distribution in dietary triacylglycerol on lymphatic lipid transport and chylomicron composition in rats.

The present study was carried out to examine if the positional distribution of medium-chain fatty acid (MCF) in dietary synthetic fat influences lymphatic transport of dietary fat and the chemical composition of chylomicrons in rats with permanent cannulation of thoracic duct. Four types of synthetic triacylglycerol were prepared: (i) sn-1 (3) MCF-sn 2 linoleic acid, (ii) interesterified sn-1(3) MCF-sn 2 linoleic acid, (iii) sn-2 MCF-sn-1(3) linoleic acid, and (iv) interesterified sn-2 MCF-sn-1(3) linoleic acid. A purified diet composed of equal amounts of the synthetic fat and cocoa butter was given to rats with permanent lymph duct cannulation. The positional distribution of MCF in the dietary fat had no significant effect on the lymph flow, triacylglycerol output, phospholipid output, lipid composition of chylomicrons, or the particle size. The positional distribution of MCF in the synthetic triacylglycerol was maintained in the chylomicron triacylglycerol. These results showed that MCF in the dietary triacylglycerol is transported into lymphatics and the positional distribution is well preserved in chylomicron triacylglycerol.

Xanthomonas albilineans Haplotype B Responsible for a Recent Sugarcane Leaf Scald Disease Outbreak in Cuba.

Over the past 3 years, the incidence of sugarcane leaf scald disease (LSD) caused by Xanthomonas albilineans has increased at alarming rates in some Caribbean countries. LSD was in latent phase since 1978, when the disease was reported in Cuba, until February 1998 when typical symptoms were observed in germ plasm collections and in some commercial plantings. More than 150 bacterial isolates from different sugarcane varieties and from different localities were isolated on Wilbrink agar medium and characterized. All isolates had shown similar cultural and biochemical patterns. However, serological differences between isolates from the recent outbreak and the ones obtained prior to 1998 were detected by indirect ELISA testing. Differences between Cuban isolates obtained prior to 1998 and those from the recent outbreak were confirmed by analysis of repetitive DNA sequences dispersed throughout the genome. According to the pattern obtained, the newer isolates were similar to reference strains classified as haplotype B by pulsed field gel electrophoresis (1). It is concluded that the recent outbreak of LSD was caused by a strain different than the ones previously detected in Cuba. Reference: (1) M. J. Davis et al. Phytopathology 87:316, 1997.

Toll-like receptors in secondary obstructive cholangiopathy.

Secondary obstructive cholangiopathy is characterized by intra- or extrahepatic bile tract obstruction. Liver inflammation and structural alterations develop due to progressive bile stagnation. Most frequent etiologies are biliary atresia in children, and hepatolithiasis, postcholecystectomy bile duct injury, and biliary primary cirrhosis in adults, which causes chronic biliary cholangitis. Bile ectasia predisposes to multiple pathogens: viral infections in biliary atresia; Gram-positive and/or Gram-negative bacteria cholangitis found in hepatolithiasis and postcholecystectomy bile duct injury. Transmembrane toll-like receptors (TLRs) are activated by virus, bacteria, fungi, and parasite stimuli. Even though TLR-2 and TLR-4 are the most studied receptors related to liver infectious diseases, other TLRs play an important role in response to microorganism damage. Acquired immune response is not vertically transmitted and reflects the infectious diseases history of individuals; in contrast, innate immunity is based on antigen recognition by specific receptors designated as pattern recognition receptors and is transmitted vertically through the germ cells. Understanding the mechanisms for bile duct inflammation is essential for the future development of therapeutic alternatives in order to avoid immune-mediated destruction on secondary obstructive cholangiopathy. The role of TLRs in biliary atresia, hepatolithiasis, bile duct injury, and primary biliary cirrhosis is described in this paper.

DDT and HCH isomer levels in soils, carrot root and carrot leaf samples.

Agricultural cultivation assists organochlorine pesticide migration from contaminated soils to growing plants. This phenomenon is caused by retention processes that modify volatile pesticide exchange between soil, air and plants. The aim of the study was to monitor organochlorine pesticide (HCB, alpha- and gamma-HCH, pp'DDE, op'DDT, pp'DDT) levels and compare these concentrations in soil, carrot roots and carrot leaves. Fifty soil samples, 50 carrot root and 50 carrot leaf samples were taken from the same fields and analyzed by GLC-ECD. The results reveal organochlorine pesticide diffusion from agricultural soils to growing carrot plants and their vapors adsorption by leaves. Within the carrot plant, organochlorine pesticides accumulate especially in carrot root peel, 3-7 times more than in root flesh.

Effect of n-3 polyunsaturated fatty acids on the lipidic profile of healthy Mexican volunteers.

OBJECTIVE: The effect of n-3 polyunsaturated fatty acids on the serum lipid profile in a Mexican population was evaluated. MATERIAL AND METHODS: Three g of salmon oil was the daily intake during four weeks. Total cholesterol, triglycerides, low density lipoproteins, high density lipoproteins and erythrocyte fatty acid composition were analyzed. RESULTS: The hypertriglyceridemic group showed a statistically significant (p < 0.05) reduction of triglycerides and significant (p < 0.01) elevation of high density lipoproteins. The hypercholesterolemic group reduced significantly the levels of cholesterol and triglycerides; high density lipoproteins were augmented by 11.6%. CONCLUSIONS: The hypolipidemic effect of n-3 polyunsaturated fatty acids was manifest in the Mexican volunteers under the conditions here evaluated.

[Pyelonephritis and bacterial tubulointerstitial nephritis]. / Pielonefritis y nefritis tubulointersticial bacteriana

With the purpose of establishing the clinicopathologic correlation in pyelonephritis and to discard other interstitial nephrites, with present day morphologic criteria we analysed 63 casos that had been diagnosed as pyelonephritis, following Weiss and Parker's histologic criterion. The clinicopathologic diagnosis of pyelonephritis was confirmed in 12 cases; all of them showed obstructive uropathy and in most of them, there was chronic renal failure. Interstitial nephritis was established in 27 cases, all of them showing septicemia and almost half of the cases showed acute renal failure. Other 20 cases showed tubulointerstitial nephritis secondary to different types of glomerulopathies, fetal glomerulosclerosis, dysplasias, nephrophthisis, radiation nephritis and renal infarct. In 4 cases, the study of sections finer than the original, showed absence of histopathologic lesions. The results of the present study point out the main causes of confusion with the pathological diagnosis of pyelonephritis, the necessity to investigate predisposing uropathy in patients with urinary infection and stresses the importance to establish correlation with clinical and laboratory findings in cases with tubulointerstitial lesions.

Persistent organochlorine pesticide levels in bovine fat from Mexico.

Organochlorine pesticides have been used in Mexico in agriculture as a seed dresser, in sanitation, in malaria control programmes and in livestock to combat ectoparasites. The pesticides applied drift to areas where cattle graze and plants grow. Because of their chemical stability, they accumulate in the lipid-rich tissues of the body. In the body, they circulate throughout all compartments and accumulate in adipose fat. The aim was to monitor the organochlorine pesticide levels in bovine muscle fat and kidney fat from cows living in an endemic malaria zone, where the environmental contamination can be suspected as being higher. Two hundred samples (100 muscle fat, 100 kidney fat) were analysed by gas chromatography. From the pesticides, only hexachlorobenzene (HCB), beta-hexachlorocyclohexane (HCH), gamma-HCH, pp'-1.1.1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT), op'-DDT and pp'-DDE, were detected frequently and at levels above the detection limits. The HCB mean level was low at 0.009 mg kg(-1) on a fat basis. From the HCH isomers, beta-HCH mean concentration was 0.039 mg kg(-1) and gamma-HCH was 0.025 mg kg(-1) on a fat basis. Among DDTs, pp'-DDT was the major constituent (0.032 mg kg(-1) on a fat basis) followed by pp'-DDE (0.025 mg kg(-1) on a fat basis) and op'-DDT (0.023 mg kg(-1) on a fat basis). The DDT total (sigma DDT) level was 0.067 mg kg(-1) on a fat basis. Comparing the previous study (1994) and the present one (2002-03), organochlorine pesticide levels were decreased. HCB decreased 3.7 times from 0.033 to 0.009 mg kg(-1) on a fat basis; beta-HCH decreased 3.8 times from 0.149 to 0.039 mg kg(-1) on a fat basis; pp'-DDE did not reveal a significant difference at 0.026 versus 0.025 mg kg(-1) on a fat basis. However, pp'-DDT decreased substantially, 6.7 times from 0.215 to 0.032 mg kg(-1) on a fat basis. The DDT total decreased 3.5 times from 0.236 to 0.067 mg kg(-1) on a fat basis. The tendency for reduced concentrations in organochlorine pesticide levels in Mexican cows is caused by their substitution with pyrethroids used in agriculture and by the Mexican Ministry of Health in sanitary programmes.

Structured triacylglycerol containing medium-chain fatty acids in sn-1(3) facilitates the absorption of dietary long-chain fatty acids in rats.

A study was carried out to examine if the positional distribution of medium chain fatty acids (MCF) in triacylglycerol influences dietary fat absorption in rats. Two types of structure-specific fats, one predominantly composed of MCF in sn-1(3) and iinoleic acid in sn-2 [sn1(3)MCF-structured] and the others of MCF in sn-2 and linoleic acid in sn-1(3) [sn-2MCF-structured], were initially prepared, and the two structure-specific fats were interesterified and designated as sn-1(3)MCF-interesterified and sn-2MCF-interesterified. Synthetic fat was mixed with an equal amount of cocoa butter (103 g/kg of diet) and was supplemented to the AIN93G-based diet. Rats were fed on the diets for 4 wk. Long-chain saturated fatty acids were the predominant fatty acids excreted into the feces, and the positional distribution of MCF resulted in an altered fat absorption rate (%) of 81.8, 82.5, 84.2 and 86.3 for the rats fed on the diets containing sn-2MCF-structured, sn-1(3)MCF-interesterified, sn-2MCF-interesterified and sn-1(3)MCF-structured fats, respectively. The proportion of MCF in the serum, liver and adipose tissue triacylglycerols was not affected by the MCF distribution of the dietary fats. These results indicate that the distribution of MCF in dietary triacylglycerol is a determinant of intestinal fat absorption.

El bajo peso al nacer es un factor de riesgo de diabetes mellitus tipo 1 / Low birth weight is a risk factor for type 1 diabetes

Introducción y objetivo: En los últimos años el aumento de la incidencia de diabetes mellitus tipo 1 (DM1) se ha relacionado con un incremento de la obesidad en la población infantil, entre otros factores. El objetivo del presente trabajo ha sido determinar de forma retrospectiva en la población española, en pacientes diagnosticados de DM1 de la Comunidad Autónoma de Madrid, la posible relación entre el peso del recién nacido, el incremento del índice de la masa corporal (IMC) en los 2 primeros años de vida y el IMC al comienzo de la enfermedad con la edad de presentación de la diabetes. Material y método: Participaron 100 niños diagnosticados de DM1 de ambos sexos (57 niños y 43 niñas), de raza caucásica, con una edad media de 84,45 meses (desviación estándar [DE] de 52,4). Se recogieron las siguientes variables: edad al comienzo de la enfermedad, edad gestacional, peso y talla de recién nacido, a los 2 años de vida y al comienzo de la enfermedad. Resultados: Los niños diagnosticados de DM1 tienen menor peso al nacer −0,288 (−0,51 a −0,066) y menor IMC (puntuación de DE) al nacer que la población sana −0,5 (−0,77 a −0,23). Además de un incremento mayor del IMC hasta los 2 años (4,58% frente a 2,17%; p<0,001). Los niños con menor IMC al nacer (12,77% frente a 13,06%; p<0,006) comienzan antes con la enfermedad. No se ha encontrado correlación entre el IMC al comienzo y el resto de las variables estudiadas. Conclusiones: El menor IMC al nacer de los pacientes con diabetes mellitus estudiados y el incremento de peso que se produce en los 2 primeros años de vida en esta población podría implicar a algunos factores durante la vida fetal como factor de riesgo de DM1 (AU)

Introduction and aim: Over recent years, the increasing incidence of type 1 diabetes mellitus (T1DM) has been associated with different factors, particularly increased obesity in childhood. The aim of this study was to find out if there was any relationship between birth weight, body mass index (BMI) increase during the first two 3 years of life, and BMI at diabetes onset with age at diagnosis, in a cohort of children diagnosed with T1DM. Material and method: Data from 100 Caucasian children with T1DM of both sexes (57 boys, 43 girls) between 10 months and 16 years of age, mean age 84.45 months (SD; 52.4), were studied. We analysed the following variables: age at diagnosis, gestational age, weight and height at birth, at two years of age and at diabetes diagnosis, expressed as SD scores (SDS). Results: All children were between 38–40 weeks of gestational age. Diabetic patients have lower birth weight (−2.88 ((−0.51)–(−0.066)) and lower BMI at birth compared with healthy children −0.5 ((−0.77)–(−0.23)). Diabetic children have a significant increase in BMI during the first two years of life (4.58 versus 2.17; P<0.001). Children with the lowest BMI at birth (12.77 versus 13.06; P<0.006) are the youngest at onset of the disease. BMI at diagnosis was not related to any of the variables studied. There were no gender differences either. Conclusions: The low BMI at birth and the later increase in the following years of life seem to be related to intrauterine environment as a risk factor for T1DM (AU)