Characterization of the iron oxide phases formed during the synthesis of core-shell FexOy@C nanoparticles modified with Ag.

Core-shell FexOy@C nanoparticles (NPs) modified with Ag were studied with x-ray diffraction, transmission electron microscopy, energy dispersive elemental mapping, Mössbauer spectroscopy, static magnetic measurements, and optical magnetic circular dichroism (MCD). FexOy@C NPs synthesized by the pyrolysis process of the mixture of Fe(NO3)3 · 9H2O with oleylamine and oleic acid were added to a heated mixture of oleylamine and AgNO3 in different concentrations. The final product was a mixture of iron oxide crystalline NPs in an amorphous carbon shell and Ag crystalline NPs. The iron oxide NPs were presented by two magnetic phases with extremely close crystal structures: Fe3O4 and γ-Fe2O3. Ag is shown to form crystalline NPs located very close to the iron oxide NPs. An assumption is made about the formation of hybrid FexOy@C-Ag NPs. Correlations were obtained between the Ag concentration in the fabricated samples, their magnetic properties and the MCD spectrum shape. Introducing Ag led to a approximately linear decrease of the NPs saturation magnetization depending upon the Ag concentration, it also resulted into the MCD spectrum shift to the lower light wave energies. MCD was also studied for the Fe3O4@C NPs synthesized earlier with the same one-step process using different heat treatment temperatures, and MCD spectra were compared for two series of NPs. A possible contribution of the surface plasmon excitation in Ag NPs to the MCD spectrum of the FexOy@C-Ag NPs is discussed.

Rapid identification of Salmonella using Hektoen enteric agar and 16s ribosomal DNA probe-gold nanoparticle immunochromatography assay in clinical faecal specimens.

UNLABELLED: A rapid identification of Salmonella, one of the most common foodborne pathogens worldwide, in clinical patients can enable better rational managements and prevent further outbreaks. The traditional immunochromatography using antibody-gold nanoparticles (Ab-AuNPs), such as the home pregnancy test, has been used for the Salmonella detection. In this study, we developed a new and rapid method using DNA probe-AuNPs for the detection of 16s ribosomal DNA of Salmonella. To evaluate the proposed method in clinical specimens, we performed a clinical test by identifying 159 stool samples on Hektoen agar containing black or crystalloid colonies using the method and the VITEK 2 system for confirmation. Eighty of the isolates were correctly identified as Salmonella to achieve 100% sensitivity. Seventy-five samples were correctly identified as non-Salmonella spp., but four were incorrectly identified as Salmonella. The specificity was 94·93%. The assay time is about 30 min after the DNA purification. The time-consuming and labour-intense biochemical tests can be replaced. We demonstrated that this assay is a rapid, convenient and cost-effective tool for Salmonella identification of clinical faecal samples, which is worth for further promotion and clinical use. This is the first application of using 16s ribosomal DNA probe-Au-NPs and immunochromatography on clinical samples. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first application of using 16s ribosomal DNA probe-gold nanoparticles and immunochromatography method on clinical samples with sensitivity 100% and specificity 94·93%. The assay time is about 30 min after the DNA purification. We find this assay a rapid, convenient, sensitive and inexpensive tool for Salmonella identification of clinical faecal samples, which is worth further promotion and clinical use and can replace the traditional time-consuming and labour-intense biochemical tests. The potential benefit of this approach is to develop a rapid point-of-care test that provides results while the patient is still at the doctors' office.

Pulmonary tumour with high carcinoembryonic antigen titre caused by chronic propolis aspiration.

Carcinoembryonic antigen (CEA) titre elevation is sometimes found in benign diseases, such as gastro-intestinal tract inflammatory disease and chronic obstructive pulmonary disease; however, very high CEA titre is rarely encountered in benign pulmonary disease. A 36-yr-old female, who had suffered from body weight loss, was found to have high serum CEA titre (60.8 ng.mL(-1)). Image studies revealed one pulmonary tumour at the left lower lobe, satellite nodules and mediastinal lymphadenopathy. Left lower lobectomy and lymph node dissection were performed for suspicious pulmonary malignancy. The pathological examination revealed that the tumourous lesion was composed of small and fragmented foreign bodies, fibrinopurulent exudate and heavy eosinophils. The bronchial epithelium was characterised by goblet cell hyperplasia and CEA overexpression. The remaining lung parenchyma possessed similar foreign body reaction. The patient's medical history was reviewed and it was found that she had spread propolis topically on nasal mucosa as an adjuvant therapy to asthma for 6 months prior to this medical event. The CEA titre decreased after the operation to 14.2 and 7.88 ng.mL(-1) after 2 weeks and 6 months, respectively. Propolis is used widely in folk medicine but it also has strong sensitising potential. One rare case of propolis aspiration is reported with presentation mimicking lung cancer.

Modified Nuss operation for pectus excavatum: design for decreasing cardiopulmonary complications.

BACKGROUND: Thoracoscopic Nuss operation of funnel chest is increasingly performed. However, it has a high rate of complications. This study developed some modifications to facilitate Nuss operations with the intention of reducing several major complications. METHODS: Patients who presented for surgical repair of pectus excavatum from July 2003 through June 2004 had a preoperative computed tomography (CT) scan, pulmonary function tests, and cardiac echo before and two months after the modified Nuss operation. The following modifications of the standard Nuss procedure were implemented: (1) One small subxyphoid incision was made to guide the plate implantation and to decrease cardiopulmonary complications. (2) Thoracic muscles were dissected off the ribs to provide muscle pockets. (3) Shorter thick stainless-steel AO bars were selected to avoid thoracic outlet syndrome and restriction. (4) The bars were fixed to adjacent ribs by 4-0 stainless steel wires into the submuscular pockets. (5) No thoracoscope routinely used. (6) No chest tubes were placed to decrease chest pain or for cosmetic purposes. RESULTS: 15 patients aged between 4 and 32 years (mean, 18.6 +/- 7.8) underwent evaluation. Preoperative CT index was 4.14 +/- 0.86. The average operating time was 95.7 +/- 27.0 min. There was no bar dislocation, prolonged pain, or neuralgia. Echocardiography showed no pericarditis and no pneumothorax occurred after placement of the intrathoracic bar. CONCLUSION: A small subxiphoid incision makes bar implantation easier and has reduced the incidence of major complications in this early experience with 15 patients.

A study of PVRL1 mutations for non-syndromic cleft lip and/or palate among Taiwanese patients.

Mutations of codons 185 and 323, especially the W185X mutation, of the PVRL1 gene among non-syndromic cleft lip and/or palate (CL/P) patients and normal controls in Taiwan were studied in order to determine whether there are mutations that play a part in the formation of non-syndromic CL/P. A total of 76 patients were enrolled; 66 sporadic non-syndromic CL/P patients and 10 normal controls. The mutation survey for codons 185 and 323 was conducted using a polymerase chain reaction and DNA sequencing. Neither mutations of codons 185 and 323 were noted for any of the 76 patients (152 alleles), nor were found any other mutations in either exon 3 or 5 of the PVRL1 gene. These results suggest that mutations of the PVRL1 gene at codons 185 and 323, especially the W185X mutation, do not participate in the formation of CL/P within the Taiwanese population examined.

Liganded and unliganded steroid receptor modulation of beta 1 adrenergic receptor gene transcription.

The classical model of gene regulation by hormones involves a hormone-bound receptor interacting with a DNA response element to increase or decrease gene transcription. Steroid hormone regulation more commonly involves atypical cis-elements, co-receptors, accessory proteins, and unique modes of interaction on different genes. The thyroid hormone and retinoic acid receptors belong to the super family of steroid nuclear receptors and may modify gene expression even in the absence of ligand binding. In these studies, we characterized thyroid receptor- and retinoic acid receptor-mediated regulation of beta1 adrenergic receptor (beta1AR) gene expression. Using cloned fragments of the ovine beta1AR in a luciferase reporter vector, we examined the effects of thyroid receptor and retinoic acid receptor, alone and in combination with T3 or retinoic acid on beta1AR expression. We examined expression in SK-N-SH neuroblastoma cells, CV-1 fibroblasts, and, in neonatal rat, primary cardiomyocytes. We demonstrated that even in the absence of ligand binding, thyroid receptor and retinoic acid receptor can significantly increase beta1AR transcription activity. This effect is important in the developmental transition in beta1AR expression during fetal and postnatal life.

Beta-adrenergic receptors (betaAR) regulate cardiomyocyte proliferation during early postnatal life.

Cardiomyocyte development switches from hyperplasmic to hypertrophic growth between postnatal days 3 and 4 in rats. The mechanisms responsible for this transition have been controversial. beta-Adrenergic receptor (betaAR) activation of mitogenic responses in vitro has been reported. We hypothesized that tonic activation of the betaAR signaling regulates cell division in neonatal cardiomyocytes via effects on signaling kinases known to be important in cell cycle regulation. The purpose of the current study was to elucidate the roles of betaAR in rat cardiomyocyte growth in vivo. We demonstrated that betaAR blockade induced a significant reduction in cardiomyocyte proliferation as measured by the BrdU labeling index. Blockade of betaAR did not affect p38 or p44/42 MAPK activities. We further demonstrated that betaAR blockade induced a prompt deactivation of the p70 ribosomal protein S6 kinase (p70 S6K). To confirm these results, we measured p70 S6K activity directly. Basal activity of p70 S6K in neonatal cardiomyocytes was fourfold higher than that of insulin-treated adult rat liver. The activity of p70 S6K was reduced by 60% within 1 min after betaAR blockade. We conclude that the betaAR are involved in regulation of neonatal cardiomyocyte proliferation and that this mitogenic control may be mediated via the p70 S6K pathway.

A novel glucocorticoid regulatory unit mediates the hormone responsiveness of the beta1-adrenergic receptor gene.

The effects of glucocorticoids on expression of the beta1-adrenergic receptor (beta1AR) gene have been varied. To study the mechanism underling hormonal regulation of the beta1AR, transient transfection of progressively deleted ovine beta1AR promoter fragments was used to identify a 43-bp region (-1274 to -1232 from the translation start site) that contains a novel glucocorticoid regulatory unit (GRU) and confers glucocorticoid responsiveness. Using DNase I footprinting and electrophoretic mobility shift assays (EMSA), we demonstrated the GRU was composed of a palindrome, 5'-TAATTA-3', which is a core binding motif for the homeodomain proteins, an E-box (5'-CACGTG-3'), binding site for the Myc/Max family proteins, and an overlapping glucocorticoid response element (GRE) half-site (5'-TGTTCT-3'). EMSA demonstrated that the GRE half-site is critical for GRU-protein interactions, which also require binding of proteins to the E-box and the homeodomain region. Co-transfection of a plasmid expressing a c-myc antisense construct significantly reduced glucocorticoid responsiveness of the ovine beta1AR promoter. Furthermore, expression of proteins binding to the GRU was shown to be developmentally regulated, being high in embryonic, reduced in newborn and not detectable in adult heart. We conclude that the ovine beta1AR promoter contains a novel, functional GRU and that glucocorticoid receptor (GR) and the Myc/Max family proteins are involved in the cell-specific nuclear factor binding and transactivation via this element. The results suggest an alternative pathway through which glucocorticoids may exert their effects on genes lacking a full consensus GRE.

Esophageal reconstruction for hypopharyngoesophageal strictures after corrosive injury.

OBJECTIVE: To evaluate the surgical outcome of patients with caustic stricture of the hypopharyngoesophagus. MATERIALS AND METHODS: During a 25-year period, we performed esophageal reconstruction in 152 patients with diffuse or multiple caustic esophageal stricture. Of them, esophageal substitute was pulled up and anastomosed to the hypopharynx in 50 (33%) patients, and anastomosed to the cervical esophagus in the other 102 (67%) patients. Patients whose esophageal substitute anastomosed to the hypopharynx were enrolled to the present study. Among these 50 study patients, 13 underwent ablation of damaged organs and feeding jejunostomy in acute stage of corrosive injury, and the remaining 37 patients were initially organ preserved with or without feeding gastrostomy or jejunostomy. Six patients had respiratory distress caused by laryngotracheal stricture. The ileocolon (28/50) was commonly used as an esophageal substitute in reconstruction and most substitutes (43/50) went through the substernal route. RESULTS: There was one operative death. Eight (16%) patients had major early postoperative complications. Six patients underwent revision for late stenosis of hypopharyngeal anastomosis, and one redoing reconstruction using the jejunum because of failure of the transplanted ileocolon. Postoperatively, swallow function and maintaining body weight were considered good in 42 patients (84%) after an average of 8 months follow-up. Five of six patients who underwent concomitant tracheostomy or laryngosurgery for laryngotracheal stricture got unsatisfactory result. The surgical outcome of the study patients was worse than that in patients with esophageal substitute anastomosed to a healthy cervical esophagus. In the later group of patients, 95/102 (93%) had good swallow function and only 7/102 (6.8%) had major early complications. CONCLUSION: Caustic stricture of the hypopharyngoesophagus is a challenging reconstructive problem. A successful reconstruction requires a correct hypopharyngeal opening and anastomosis, a good esophageal substitute, and a patent esophageal route and airway.

Cloning and sequence analysis of the rat norepinephrine transporter promoter.

We isolated a 2.5-kb fragment of the promoter for the rat norepinephrine transporter (NET) gene. The transcription start site was identified approximately 200 base pairs upstream from the translation start site. Several potential regulatory elements were identified by sequence analysis. The structure of the rat NET promoter was compared to mouse and human. Expression studies in placental and neuroblastoma cells suggested the presence of a 'repressor' element more than 500 base pairs upstream from the transcription start site. These studies provide the basis for examination of transcriptional regulation of this gene and for understanding its temporal and tissue-specific modes of regulation.

Magnesium in drinking water and the risk of death from diabetes mellitus.

This report examines whether magnesium in drinking water is protective against the probability of dying from diabetes mellitus. All eligible deaths from diabetes (6781 cases) of Taiwan residents from 1990 through 1994 were compared with deaths from other causes (6781 controls), and the levels of magnesium in the drinking water of these residents was determined. Data on magnesium levels in drinking water throughout Taiwan were obtained from the Taiwan Water Supply Corporation (TWSC). Controls were pair matched to the cases by sex, year of birth, and year of death. The results of the present study show that there seems to be a significant protective effect of magnesium intake from drinking water on the risk of dying from diabetes mellitus. This is an important finding for the Taiwan water industry and human health.

Pancreatic cancer mortality and total hardness levels in Taiwan's drinking water.

The possible association between the risk of pancreatic cancer mortality and hardness levels in drinking water from municipal supplies was investigated in a matched case-control study in Taiwan. All eligible pancreatic cancer deaths (883 cases) of Taiwan residents from 1990 through 1994 were compared with deaths from other causes (883 controls), and the hardness levels of the drinking water used by these residents were determined. Data on water hardness throughout Taiwan was collected from Taiwan Water Supply Corporation (TWSC). The control group consisted of people who died from other causes and were pair matched to the cancer cases by sex, year of birth, and year of death. The results show that there is a 39 % excess risk of mortality from pancreatic cancer in relation to the use of soft water. Trend analyses showed an increasing odds ratio for pancreatic cancer with decreasing levels of hardness in drinking water. This is an important finding for the Taiwan water industry and human health.

Effects of gender and age on plasma levels of clozapine and its metabolites: analyzed by critical statistics.

BACKGROUND: Previous reports concerning the effects of gender and age on steady-state plasma concentrations of clozapine and its major metabolites, norclozapine and clozapine-N-oxide, have been controversial. Since the frequency distribution of the plasma levels is asymmetrical and skewed to the right, the statistical methods (such as analysis of variance and regression analysis) used earlier are actually inappropriate for analyzing the effects of the variables on the concentrations and might contribute to the inconsistent results. The goal of the present study, with befitting statistics, is to measure the potential effect of dose, gender, age, and body weight on plasma levels of clozapine and its 2 major metabolites. METHOD: We retrospectively analyzed data from a therapeutic drug monitoring study for steady-state plasma clozapine, norclozapine, and clozapine-N-oxide levels that was conducted in a large group of Chinese schizophrenic inpatients (male:female ratio = 83:79; age range, 33.8 +/- 9.3 years). The daily doses of clozapine had ranged from 100 to 900 mg, with a mean +/- SD value of 379.5 +/- 142.2 mg. Plasma concentrations had been measured using high-performance liquid chromatography with ultraviolet detection. Multiple linear regression was adopted to quantify the effects of various factors on the plasma levels. The natural logarithm of the plasma level was used as the dependent variable to overcome the skewness problem. RESULTS: After adjusting the effects of gender, age, and body weight by multiple linear regression, each 1-mg increment in the daily dose could raise the clozapine level by 0.31%, norclozapine by 0.27%, and clozapine-N-oxide by 0.16%. Female patients had 34.9% higher clozapine levels and 36.3% higher norclozapine, with other variables being controlled. No sex differences were demonstrated for clozapine-N-oxide levels. Each 1-year increment in age would elevate the clozapine level by 1.1%, norclozapine by 1.0%, and clozapine-N-oxide by 1.0%. Body weight could not influence the levels of these compounds. CONCLUSION: The present results suggest that women possess higher plasma levels (about one third higher) of clozapine and norclozapine, but not the N-oxide metabolite. Each addition of 1 year in age elevated clozapine and either metabolite's levels by about 1%. Furthermore, every 1-mg increase in the daily dose raised clozapine and norclozapine concentrations by approximately 0.3%. These findings could assist clinicians in optimizing clozapine dosing strategies.

Placental biogenic amine transporters: in vivo function, regulation and pathobiological significance.

The biogenic amine transporters are part of a large family of plasma membrane transporters. These carriers mediate the re-uptake of neurotransmitters from the synaptic cleft and plasma compartments. Re-uptake process is inhibited by drugs like cocaine, fluoxetine and tricyclic antidepressants. There are specific transporters for norepinephrine, epinephrine, dopamine and serotonin. The placenta expresses the norepinephrine and serotonin transporters, which is unusual as they are otherwise expressed predominantly in neuronal tissue. Fetal catecholamine clearance rate is higher than under any other physiological conditions and is mediated in large measure by the placental transporters. The high intrauterine catecholamine secretion and clearance rates are part of the unique fetal neuroendocrine milieu. They condition the fetus to a high capacity for catecholamine secretion in the early postnatal period when elevated sympathoadrenal system activity is vital for postnatal survival. Because of the prominent catecholamine clearance rate, the fetus is vulnerable to the adverse effects of re-uptake inhibitors. Understanding the mechanisms of expression and regulation of placental biogenic amine transporters is important to the pathobiology of fetal conditions associated with elevated catecholamine levels or intrauterine exposure to uptake inhibitors like cocaine.

Expression of a pulmonary endothelial norepinephrine transporter.

To determine whether pulmonary endothelial cells express the plasma membrane norepinephrine transporter (NET), an ovine-specific riboprobe was prepared from a partial NET cDNA clone isolated by PCR from a placental cDNA library. Northern hybridization detected a predominant 5.8 kb and a weaker transcript at 3.6 kb in RNAs isolated from near-term ovine fetal pulmonary endothelial cells. These data should be useful for future studies examining the molecular mechanisms underlying pulmonary endothelial NET expression and regulation.

An inverted cAMP response element mediates the cAMP induction of the ovine beta 1-adrenergic receptor gene.

We identified an inverted, functional cAMP response element (CRE) located at--1599 bp relative to the translation start site within the ovine beta 1-adrenergic receptor (beta 1 AR) gene promoter. In transfection studies with SK-N-MC cells, a 40-bp oligonucleotide containing the potential CRE, beta 1 AR-CRE, conferred a 3- to 4-fold increase in luciferase activity mediated by cAMP. The induction was mimicked by co-transfecting the cells with a vector overexpressing the alpha-catalytic subunit of the cAMP-dependent protein kinase (PKA) without treatment, and was blocked by overexpressing a PKA inhibitor (PKI). In electrophoretic mobility shift assays, a discrete binding pattern was shown in cell nuclear extract probed with the 40 bp beta 1 AR-CRE. The binding was shown to be specific and supershifted by addition of a CRE binding protein (CREB-1) antibody. These data demonstrate that cAMP mediates the induction of beta 1 AR gene expression by interacting with an inverted CRE within the promoter region. This is the first reported functional CRE among all beta 1 AR genes.

Placental biogenic amine transporters: cloning and expression.

During intrauterine development, catecholamine turnover (production and clearance rates) is higher than under any other circumstances. This is mediated in large part by placental clearance of circulating catecholamines via a cocaine-sensitive, neuronal transporter-dependent mechanism. In order to confirm the molecular mechanisms for placental transport, we screened an ovine placental cDNA library for biogenic amine transporters. We report here the identification of two biogenic amine transporters with sequences very similar to their neuronal counterparts. One is an ovine serotonin transporter (oSERT) with > 90% homology to the human neuronal SERT. Expression studies confirm transport and competitive binding affinities consistent with a SERT transporter. We have also isolated a partial sequence for the ovine norepinephrine transporter (oNET). These results confirm the placental expression of plasma membrane biogenic amine transporters. We suggest the exaggerated fetal vulnerability to uptake inhibitors, like cocaine, may be due to blockade of placental biogenic amine transport.

Human placental norepinephrine transporter mRNA: expression and correlation with fetal condition at birth.

The purpose of this study was to determine the primary form of human placental norepinephrine transporter (hNET) mRNA expressed in the human placenta and to compare the level of expression in normal pregnancies and in pregnancies complicated by drug exposure or other forms of physiological derangement. We used the hNET cDNA to measure RNA extracted from placenta and examined placental RNA following complicated and uncomplicated pregnancies. To compare transporter expression and its relation to fetal condition at birth, umbilical arterial plasma catecholamine levels, umbilical arterial blood gases and placental transporter mRNA level were compared by linear regression analysis. Uncomplicated pregnancies had a higher level of placental norepinephrine transporter mRNA than complicated pregnancies. An inverse relationship between umbilical cord norepinephrine level and transporter expression was demonstrated. We conclude that placental transporter expression represents an important and newly described metabolic function of the placenta. Placental catecholamine clearance mediated via the placental NET may be important in the pathophysiology of disorders associated with placental dysfunction, impaired placental blood flow or intrauterine growth retardation. This may also explain the adverse effects of drugs, such as cocaine, which block catecholamine transport.