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Biomedical subjects

C Castillo

Publications and source records attributed to C Castillo.

At least 55 records · Page 3Linked to original sources
PubMed2000

Smad7 is a TGF-beta-inducible attenuator of Smad2/3-mediated inhibition of embryonic lung morphogenesis.

Smad7 was recently shown to antagonize TGF-beta-induced activation of signal-transducing Smad2 and Smad3 proteins. However, the biological function of Smad7 in the process of lung organogenesis is not known. Since Smad2/3-mediated TGF-beta signaling is known to inhibit embryonic lung branching morphogenesis, we tested the hypothesis that Smad7 regulates early lung development by modulating TGF-beta signal transduction. An antisense oligodeoxynucleotide (ODN) was designed to specifically block endogenous Smad7 gene expression at both transcriptional and translational levels in embryonic mouse lungs in culture. TGF-beta-mediated inhibition of lung branching morphogenesis was significantly potentiated in cultured embryonic lungs in the absence of Smad7 gene expression: abrogation of Smad7 potentiated TGF-beta-mediated inhibition of lung branching morphogenesis from 76 to 52% of the basal level in lungs cultured in the presence of 5 ng/ml TGF-beta1 ligand. Likewise, TGF-beta1 EC(50) (concentration of TGF-beta1 that induced half maximal branching inhibition) was reduced from 5 to 1 ng/ml when Smad7 gene expression was abrogated in lung culture, indicating an enhanced level of TGF-beta signaling in lung tissue with abolished Smad7 gene expression. By immunocytochemistry, Smad7 protein was co-localized with both Smad2 and Smad3 in distal bronchial epithelial cells, supporting the concept that Smad7 inhibits TGF-beta signaling by competing locally with Smad2 and Smad3 for TGF-beta receptor complex binding during lung morphogenesis. Furthermore, antisense Smad7 ODN increased the negative effect of TGF-beta1 on epithelial cell growth in developing lungs in culture. We also demonstrated that Smad7 mRNA levels were rapidly and potently induced upon TGF-beta1 stimulation of lungs in culture, suggesting that Smad7 regulates TGF-beta responses in a negative feedback loop. These studies define a novel function for Smad7 as an intracellular antagonist of TGF-beta-induced, Smad2/3-mediated inhibition of murine embryonic lung growth and branching morphogenesis in culture. The optimization of TGF-beta signaling during early lung development therefore requires a finely-regulated competitive balance between both permissive and inhibitory members of the Smad family.

Animals↗
PubMed2000

The effect of pig farming on copper and zinc accumulation in cattle in Galicia (north-western Spain).

Copper and zinc are frequently added at high concentrations to pig diets as growth promoters. Livestock grazing pasture contaminated with pig slurry may, therefore, be at risk from excessive intake of these elements. High liver copper concentrations have been detected in cattle from the agricultural region of Galicia (NW Spain), especially where there is intensive pig farming. The aim of this study was to evaluate whether pig farming does affect accumulation of copper and zinc in cattle in Galicia. Hepatic copper and zinc concentrations in calves were elevated in areas with naturally high levels of these elements in the soil. The densities of young pigs (piglets and growing-finishing pigs), but not reproductive sows, also influenced copper accumulation in calves. Liver copper levels in calves were significantly and positively related to the density of young pigs in the region. In areas with the highest pig densities, more than 20% of the cattle analysed had hepatic copper concentrations that exceeded the potentially toxic concentration of 150 mg/kg fresh weight. There was no evidence that zinc accumulation in calves was affected by pig density.

Animals↗
PubMed2000

Toxic and trace elements in liver, kidney and meat from cattle slaughtered in Galicia (NW Spain).

The aims of this study were to determine the levels of some toxic and trace metals in cattle meat in Spain and to compare them with concentrations in cattle elsewhere and to maximum acceptable levels. Arsenic, cadmium, lead, copper and zinc concentrations in the liver, kidney and muscle (meat) from 438 calves (6-10 months old) and 56 cows (2-16 years old) slaughtered in Galicia (NW Spain) in 1996 were quantified. The arithmetic mean fresh weight concentrations in calf liver, kidney and muscle respectively were 0.043, 0.055, 0.004 mg/kg for arsenic, 0.032, 0.070, 0.001 mg/kg for cadmium, 0.053, 0.052, 0.009 mg/kg for lead, 64.6, 4.91, 0.677 mg/kg for copper and 47.7, 14.4, 47.8 mg/kg for zinc. In cows, these concentrations were 0.046, 0.068, 0.005 mg/kg (arsenic), 0.097, 0.458, 0.001 mg/kg (cadmium), 0.057, 0.066, 0.017 mg/kg (lead), 60.3, 3.67, 1.26 mg/kg (copper) and 59.8, 20.0, 52.7 mg/kg (zinc). Except for copper levels in the liver which were high, metal concentrations in cattle were generally low in Galicia and broadly similar to those in the rest of Europe, Australia and Canada. Arsenic, cadmium and lead concentrations in Galician cattle rarely exceeded acceptable maximum concentrations that have been adopted by many countries. Copper and zinc concentrations in Galician cattle did exceed acceptable maximum concentrations but the frequency with which this occurred depended upon which acceptable maximum concentration was used; regulatory values differ markedly between countries.

Animals↗
PubMed2000

Nortriptyline versus fluoxetine in the treatment of depression and in short-term recovery after stroke: a placebo-controlled, double-blind study.

OBJECTIVE: This study compared nortriptyline and fluoxetine with placebo in the treatment of depression and in recovery from physical and cognitive impairments after stroke. METHOD: A total of 104 patients with acute stroke enrolled between 1991 and 1997 entered a double-blind randomized study comparing nortriptyline, fluoxetine, and placebo over 12 weeks of treatment. The majority of patients were recruited from a rehabilitation hospital in Des Moines, Iowa, but other enrollment sites were also used. Both depressed and nondepressed patients were enrolled to determine whether improved recovery could be mediated by mechanisms unrelated to depression. Nortriptyline in doses of 25 mg/day gradually increased to 100 mg/day or fluoxetine in doses of 10 mg/day gradually increased to 40 mg/day or identical placebo were given over 12 weeks. Response to treatment of depression for individual patients was defined as a greater-than-50% reduction in scores on the Hamilton Rating Scale for Depression and no longer fulfilling diagnostic criteria for major or minor depression. Improved recovery for a treatment group was defined as a significantly higher mean score from baseline to end of the treatment trial, compared with patients treated with placebo, on measures of impairment in activities of daily living and levels of cognitive and social functioning. RESULTS: Nortriptyline produced a significantly higher response rate than fluoxetine or placebo in treating poststroke depression, in improving anxiety symptoms, and in improving recovery of activities of daily living as measured by the Functional Independence Measure. There was no effect of nortriptyline or fluoxetine on recovery of cognitive or social functioning among depressed or nondepressed patients. Fluoxetine in increasing doses of 10-40 mg/day led to an average weight loss of 15. 1 pounds (8% of initial body weight) over 12 weeks of treatment that was not seen with nortriptyline or placebo. CONCLUSIONS: Given the doses of medication used in this study, nortriptyline was superior to fluoxetine in the treatment of poststroke depression. Demonstrating a benefit of antidepressant treatment in recovery from stroke may require the identification of specific subgroups of patients, alternative measurement scales, or the optimal time of treatment.

Activities of Daily Living↗
PubMed2000

Effect of sex on arsenic, cadmium, lead, copper and zinc accumulation in calves.

This study evaluated the effect of sex on the accumulation of arsenic, cadmium, lead, copper and zinc in calves. Samples of liver, kidney, muscle and blood of 312 animals (127 females and 185 males) were analysed after acid digestion using atomic absorption spectrophotometry (AAS). Arsenic was determined by AAS interfaced with continuous flow hydride generation, cadmium and lead by graphite furnace, and copper and zinc by flame. Females accumulated more cadmium, copper and zinc in kidneys than did males. The zinc blood levels in females were higher than in males, whereas copper in liver was higher in males than in females. In the case of arsenic and lead, no significant statistical differences between males and females were found.

Animals↗
PubMed2000

[Risk factors for home deaths due to pneumonia among low socioeconomic level Chilean children, Santiago de Chile (1994)].

BACKGROUND: Pneumonia is the main cause of late infant mortality in Chile. Over 60% of these deaths occur at home. The lack of hospital beds and the inadequate outpatient management are contributing factors. AIM: To assess risk factors for home deaths due to pneumonia in Chilean children. PATIENTS AND METHODS: The clinical and environmental histories of 53 (39 male) children that died due to pneumonia in their homes were analyzed. The cause of death was confirmed by necropsy with histopathological studies in all cases. These cases were compared with 88 control children of similar age, gender, socioeconomic status and living in the same geographical area of Metropolitan Santiago. RESULTS: Fifty four percent of deceased children were of less than 3 months of age and only 3 cases and their controls were above 1 year old. Identified risk factors for death were malnutrition with an odds ratio of 30.6 (CI 3.9-64.8, p < 0.001), low birth weight with an odds ratio of 5 (CI 1.8-14.1, p < 0.001), previous admissions to hospitals with an odds ratio of 5.79 (CI 2-17.1, p < 0.001), congenital malformations (mainly cardiac) with an odds ratio of 8.4 (CI 2-39.9, p = 0.001) and a history of bronchial obstruction with an odds ratio of 5.68 (p < 0.001). Identified maternal risk factors were smoking with an odds ratio of 4.13 (CI 1.6-10.7 p < 0.001) and being a teenager with an odds ratio of 4.3 (CI 1.7-11, p < 0.001). Malnutrition, low birth weight, history of previous hospital admissions and having a teenager or smoker mother were considered as independent risk factors using a stepwise analysis. CONCLUSIONS: Chilean low income children have identifiable risk factors for death at their homes due to pneumonia, that can be preventively managed.

Adolescent↗
PubMed2000

[Prevalence of anti-hantavirus antibodies in health care personnel in direct contact with patients with hantavirus pulmonary syndrome in Temuco, Chile 1997 to 1999].

BACKGROUND: An outbreak of Hantavirus Cardiopulmonary Syndrome (HVCS) caused by the Andes virus, affected Chile since 1995. Antibodies to Hantavirus in health care workers who had cared patients with HVCS in Coybaique, Argentinean reports and familial clustering of bantaviral illness, raised the possibility of person to person transmission. Familial clustering could occur secondary to a similar exposure to a common infected environment of more than one member of the family. Moreover, the prevalence of antibodies in health care workers in Coyhaique does not differ from the prevalence in general population in that region. AIM: To study the prevalence of antibodies to Hantavirus in health care workers exposed to body fluids of 20 patients. MATERIAL AND METHODS: Among health care workers exposed to patients with HVCS, we registered information about the exposure to patients and to the environment outside the hospital in which they could have been infected. IgG antibodies against Hantavirus were measured by ELISA using two dilutions. RESULTS: Sixty seven workers were studied. Of these, 73% were exposed to respiratory secretions and blood, 21% to blood and 6% to respiratory secretions. Only 6% protected themselves properly, 49% used facial masks and gloves, 25% only facial masks, 7% only gloves and 12% used no protection measures. In none of these workers, Hantavirus antibodies were detected. CONCLUSIONS: These results are supporting evidence against person to person transmission of the Andes virus.

Adult↗
PubMed1999

Giardia lamblia: incorporation of free and conjugated fatty acids into glycerol-based phospholipids.

Giardia lamblia trophozoites are flagellated protozoa that inhabit the human small intestine, where they are exposed to various dietary lipids and fatty acids. It is believed that G. lamblia, which colonizes a lipid-rich environment of the human small intestine, is unable to synthesize phospholipids, long-chain fatty acids, and sterols de novo. Therefore, it is possible that this protozoan has developed a special process for acquiring lipids from its host. We have previously shown that G. lamblia can take up saturated fatty acids and incorporate them into phosphatidylglycerol (PG) and other glycerol-based phospholipids (Stevens et al., Experimental Parasitology, 86, 133-143, 1997). In the present study, an attempt has been made to investigate the underlying mechanisms of transesterification and interesterification reactions of giardial phospholipids by free and conjugated fatty acids. Results show that exogenously supplied, unsaturated, fatty acids were taken up by Giardia and incorporated into various phosphoglycerides, including PG. To test whether this intestinal pathogen can utilize conjugated fatty acids, live trophozoites were exposed to either [3]H;cbphosphatidylcholine (PC), where the fatty acid was 3H-labeled at its sn2 position, or to [14C]lyso-PC (fatty acid was 14C-labeled at the sn1 position) for 90 min, followed by phospholipid analysis using thin-layer chromatography. The results suggest that conjugated fatty acids, like free fatty acids, were incorporated into PG. It was also observed that aristolochic acid, an inhibitor of Ca2+-ionophore-stimulated phospholipase A2, decreased the transfer of fatty acids from [3H]PC to PG, indicating that giardial phospholipases were involved in these esterification reactions. Additional experiments, which include culturing trophozoites in serum-supplemented and serum-deprived medium, along with numerous biochemical analyses suggest that (i) PG is a major transesterified and interesterified product, (ii) it is likely that giardial phospholipases are involved in esterification reactions, (iii) in G. lamblia, PG is localized in perinuclear membranes, as well as intracellularly, but not in the plasma membrane, and (iv) various synthetic analogs of PG inhibit the growth of the parasite in vitro. These studies suggest that PG is an important phospholipid of Giardia and a potential target for lipid-based chemotherapy against giardiasis.

Animals↗
PubMed1999

Morphology and amplitude values of the P and T waves in the electrocardiograms of Spanish-bred horses of different ages.

This investigation was undertaken to determine values of electrocardiographic parameters in Spanish-bred horses at different stages of growth. The study was carried out on 179 healthy Spanish-bred (Andalusian) horses (98 females and 81 males), which were aged between 1 month and 17 years. The ECGs showed P waves of different configurations. The bifid shape deflection of the P wave was generally more frequent than the simple one in animals from 6 months of age. The first component of bifid P waves (P1) did not vary in a statistically significant way with increasing age, showing a mean value of 0.105 mV. The amplitudes of the P2 (the second component of the bifid P waves) and simple P waves showed statistically significant differences between the age groups. The highest values were found in animals up to 3 months and over 2 years of age. Several configurations of the T wave were observed in the different age groups: a negative shape was generally present for the youngest animals (foals up to 2 years old); the biphasic (/+) pattern became more frequent in animals 3 and 4 years old. In adult horses the positive configuration was the most frequent. No statistically significant differences according to age were found for the amplitude values of the different T-wave configurations.

Aging↗
PubMed1999

Thiopental inhibits nitric oxide production in rat aorta.

We studied whether thiopental affects endothelial nitric oxide dependent vasodilator responses and nitrite production (an indicator of nitric oxide production) elicited by acetylcholine, histamine, and A23187 in rat aorta (artery in which nitric oxide is the main endothelial relaxant factor). In addition, we evaluated the barbiturate effect on nitric oxide synthase (NOS) activity in both rat aorta and kidney homogenates. Thiopental (10-100 microg/mL) reversibly inhibited the endothelium-dependent relaxation elicited by acetylcholine, histamine, and A23187. On the contrary, this anesthetic did not modify the endothelium-independent but cGMP-dependent relaxation elicited by sodium nitroprusside (1 nM - 1 microM) and nitroglycerin (1 nM - 1 microM), thus excluding an effect of thiopental on guanylate cyclase of vascular smooth muscle. Thiopental (100 microg/mL) inhibited both basal (87.8+/-14.3%) and acetylcholine- or A23187-stimulated (78.6+/-3.9 and 39.7+/-5.6%, respectively) production of nitrites in aortic rings. In addition the barbiturate inhibited (100 microg/mL) the NOS (45+/-4 and 42.8+/-9%) in aortic and kidney homogenates, respectively (measured as 14C-labeled citrulline production). In conclusion, thiopental inhibition of endothelium-dependent relaxation and nitrite production in aortic rings strongly suggests an inhibitory effect on NOS. Thiopental inhibition of the NOS provides further support to this contention.

Acetylcholine↗
PubMed1999

[Maternal height and growth of Chilean premature infants].

The aim of this study was to analyze the association between maternal age and growth of infants born preterm through the first 4 mo. of age. We prospectively studied 80 infant born at the hospital Herminda Martin in Chilean between January and September 1995 with birthweight < 2500 g and gestational age < or = 36 weeks; those born small for date, with congenital malformations or developing chronic diseases were excluded. The modified Graffar was applied to study socioeconomic status and growth, morbidity and type of feeding was monthly registered at Primary Care Centers where they were controlled. The maternal height was categorized as small (< -1 SD, n = 14), normal (> -1 SD and < +1 SD, 147.6-161.8 cm, n = 52) or tall (> +1 SD, n = 14). Sons from tall mothers presented better W/A z score at 4 mo than those from normal or small mothers (0.85 +/- 0.8 vs 0.31 +/- 0.6, p < 0.03 and 0.85 +/- 0.8 vs 0.15 +/- 0.8, p < 0.04). Length gain through the 4 mo was also better of infants with tall mothers (15.3 +/- 1.4 vs 13.7 +/- 2.3 and 13.6 +/- 2.2 cm, ANOVA p < 0.04), reaching better z-scores (0.2 +/- 0.3 vs -0.7 +/- 0.6 and -0.9 +/- 0.9, ANOVA p < 0.0001). The maternal schooling > 8 y was also associated to infant growth: those with tall mothers presented better L/A z-score at 4 mo than those with normal or small mothers (0.27 +/- 0.3 vs -0.89 +/- 0.7 and -0.85 +/- 0.5 p < 0.001). Exclusive breast milk was present in 7% of tall, 25% of normal and 0% of small mothers. No differences in morbidity were observed between groups. We conclude that Chilean infants born preterm from mothers > 1.61 m present a better growth that those with smaller mothers since the first 4 months of age.

Analysis of Variance↗
PubMed1998

Plasma methadone concentrations as an indicator of opioid withdrawal symptoms and heroin use in a methadone maintenance program.

Plasma methadone concentrations and its main metabolite D,L-2-ethylidiene-1,5-dimethyl-3,5-diphenylpyrrolidine (EDDP) were determined in 93 patients under methadone maintenance treatment to assess their relationship with heroin use and opioid withdrawal symptoms. Neither plasma concentrations of methadone nor EDDP were significantly different when patients that used heroin in last 3 months were compared with those testing negative for this drug (methadone, 355 +/- 217 versus 369 +/- 216 ng/ml, t = 0.29, P = NS; EDDP, 49 +/- 28 versus 54 +/- 40 ng/ml, t = 0.51, P = NS). No correlation between opioid withdrawal scale scores and plasma concentrations of methadone (r = 0.02, P = NS) and EDDP (r = -0.14, P = NS) was found. Therapeutic drug monitoring during methadone maintenance seems to be useful for assessing compliance with treatment but not for predicting heroin use and subjective withdrawal symptoms.

Adult↗
PubMed1998

Microanatomical considerations for the fenestration of the septum pellucidum.

The anatomical foundations for the endoscopic fenestration of the septum pellucidum have not been presented previously in an isolated fashion. Using a surgical microscope, the microsurgical anatomy of the septum pellucidum, lateral ventricles, and surrounding structures was examined in ten adult brains injected with silicone rubber. The mean anteroposterior length of the septum pellucidum was 41 mm (range 40-42). Its mean height was 13.11 mm (range 12-15) at the level of the foramen of Monro; 10 mm (range 9-11) at the frontal horns, and 8 mm (range 7-10) at the ventricular atrium. One to three septal veins delimited 2 or 3 avascular areas in the septum pellucidum. We found an anterior area which was consistently avascular and large enough to be fenestrated safety. More posterior areas, while avascular, were inconsistent in their size and shape.

Adult↗
PubMed1998

Microsurgical anatomy of the suboccipital segment of the vertebral artery.

The craniocervical regions of seven cadavers (14 sides) injected with silicone rubber were dissected under a Zeiss OPMI surgical microscope. The present study provides a detailed description of the suboccipital segment of the vertebral artery, with particular attention to its loops, branches, supporting osteofibrous structures, adjacent nerves, and surrounding venous structures. Several ligaments fixating the vertebral artery to surrounding structures, which have not been described in previous anatomical studies, were found. The authors propose an anatomically based subdivision of the suboccipital segment of the vertebral artery into five subsegments: infraforaminal, foraminal, supraforaminal, horizontal, and intramembranous. Measurements of surgically and clinically important features were obtained. Surgical approaches to this region are suggested based on a more informed understanding of the local anatomy.

Cadaver↗
PubMed1998

Modifications of the form and amplitude of the electrocardiographic QRS complex during growth in the Spanish-bred Horse.

Configuration and amplitude values of the QRS complex of the electrocardiogram were studied with standard Einthoven leads in 173 healthy Spanish-bred (Andalusian) horses, aged between 1 month and 17 years. Animals which were 1 month old had a predominantly negative QRS complex, whereas a predominantly positive complex direction was found in the rest of the animals. Statistically significant variations were found for the Q-wave and QRS main vector between the different age groups, with highest values for the Q-wave and most negative values for the direction of the QRS main vector in animals up to 2 months of age. The effect of age on the form and amplitude values of the QRS complex could be related to the changes in size and position of the heart in the thorax during growth. This study provides standard electrocardiographic values for the Andalusian horse at different ages.

Aging↗