Ultrasensitive microarray bioassays using cyanine5 dye-doped silica nanoparticles.

Herein we report the use of high brightness Cyanine5-doped silica nanoparticles (NPs) for the detection of antibodies or DNA in microarray bioassays. NP labels showed negligible non-specific binding, greater sensitivity and lower limits of detection when compared to free dye-labelled biomolecules. Moreover, the spotted microarrays used in this study required low NP and antibody concentrations to generate large data sets with improved statistical accuracy. These NPs have significant potential for use in biosensing for disease detection.

Multivalent linkers for improved covalent binding of oligonucleotides to dye-doped silica nanoparticles.

This paper describes the fabrication of oligonucleotide-coated Cy5-doped silica nanoparticles using a combination of multivalent linkers and their use in surface-based DNA sandwich hybridization assays. Dipodal silane is introduced as a means to fabricate amine-coated silica nanoparticles and its advantages compared to monopodal silanes are discussed. The use of dipodal silane in conjunction with three different polymer linkers (oxidized dextran, linear and 8-arm polyethylene glycol (PEG)) to immobilize single-stranded DNA to Cy5-doped nanoparticles is investigated and dynamic light scattering measurements and Fourier transform infrared spectroscopy are used to follow the progression of the functionalization of the nanoparticles. We observe a significant improvement in the binding stability of the single-stranded DNA when the dipodal silane and 8-arm PEG are used in combination, when compared to alternative conjugation strategies. Both 8mer and 22mer oligonucleotides are securely conjugated to the high-brightness nanoparticles and their availability to hybridize with a complementary strand is confirmed using solution-based DNA hybridization experiments. In addition, a full surface-based sandwich assay demonstrates the potential these nanoparticles have in the detection of less than 500 femtomolar of a DNA analogue of micro RNA, miR-451.

Controlling wettability of PECVD-deposited dual organosilicon/carboxylic acid films to influence DNA hybridisation assay efficiency.

Herein, plasma polymerisation of a dual-layer tetraethyl orthosilicate (TEOS) and acrylic acid (AA) film under a specific recipe is performed. Newly deposited films are found to retain a weakly-bound soft layer of partially polymerised acrylic acid (wbAA), which can be ultimately removed by washing. However, when on the surface, this soft layer is shown to be influential in manipulating the properties of a robust covalently-bound AA (cbAA) underlayer when treated appropriately. Specifically, treatment of the as-deposited dual-layer TEOS/AA films via timed incubation in a humidity-controlled environment results in changes in the water contact angle (WCA) of the cbAA, and ultimately the surface of the TEOS/AA, enabling tuning of the wettability of the acrylic acid layer. Through the use of a controlled incubation environment of the TEOS/AA, followed by washing, we have demonstrated that carboxylic-acid containing surfaces with a WCA between 85° and 10° can be routinely generated, using basic apparatus and simple methodology. Moreover, these surfaces not only retain their AA functionality, demonstrated by covalent-linking of amine-terminated single-stranded DNA, but also strongly inhibit non-specific binding of the DNA strands. The efficiency of these surfaces to be used in DNA direct-binding hybridisation assays has been demonstrated, with limits of detection of 1.11 and 1.66 nM being measured.

Reality shock: a case study in the socialization of new residents.

For the graduating medical student, the transition from medical school to residency can be stressful. Although much has been written about resident stress, little attention has been directed to the socialization process of medical students entering a residency program. This case report describes a difficult experience with the socialization of a class of new family practice residents. A model of professional socialization called "reality shock" is presented. Strategies and educational interventions aimed at helping overcome reality shock are described.

Type A behavior in married couples in a family practice population.

Type A behavior is characterized by status insecurity, hyperaggressiveness, free-floating hostility, time urgency, and self-destructive tendencies. In this cross-sectional study, a sample of 72 married couples from a family practice residency patient population completed self-administered questionnaires assessing the relationship between behavior type and perceived stress, social support, health perceptions, psychosomatic symptoms, health habits, marital discord, and family function. Type A men slept less, had more headaches, and reported more job stress than type B men. Type A women tended to report more frequent abdominal pains and backaches and perceived more job stress than type B women. The behavior types of marital partners did not affect various measures of family function. Assessments of family function by individual spouses were remarkably similar.

Peer coaching in clinical teaching: a case report.

Peer coaching is a method for improving teaching skills that was developed for use in general educational classroom settings. Key elements of peer coaching include the identification of specific goals for improving teaching skills, focused observation of teaching by colleagues, and the provision of feedback, analysis, and support. As part of a faculty development project, we adapted peer-coaching methodology to the clinical teaching setting. This report describes the experiences of two family physicians who have served as peer coaches for each other over the past 2 years. The participating physicians report enthusiastically about their experiences with peer coaching as a method for personalized faculty development. They report more self-awareness of their clinical teaching behaviors, the ability to improve specific teaching skills, and the rewards of a collaborative relationship between colleagues.

Continuity of care during pregnancy: the effect of provider continuity on outcome.

Continuity of care during pregnancy was examined in a family practice residency setting. The effect of provider continuity on the rate of pregnancy complications and patient satisfaction was studied prospectively in a sample of 61 patients. Patients in this study placed relatively low value on continuity of care. Pregnancy complications were predicted by traditional prenatal risk factors. Perceived waiting time in the office had the greatest effect on patient satisfaction. Provider continuity had no significant effect on either outcome.

Integrating the family into routine patient care: a qualitative study.

BACKGROUND: The field of family medicine has been enriched by a family-oriented approach and the inclusion of family systems concepts. Keeping the family as a central focus of care has been a fundamental commitment of family medicine. This research examines how exemplary physicians ("exemplars") integrate a family-oriented approach into the routine care of individual patients. METHODS: Four family physician exemplars were observed. A total of 16 days was spent observing the physicians; 137 physician-patient encounters were audiotaped, transcribed, and analyzed. Grounded theory was used for analysis, and a model of a family-oriented approach was developed. RESULTS: Visits were classified by the reason for visit and the intensity of family-oriented talk and actions. There was modest variation among the physicians in terms of intensity and time spent with patients. Overall, 19% of patient encounters had a high intensity of family-orientedness; 34% were of low intensity. The average time spent with patients was 13 minutes, with visits ranging from 3 to 39 minutes in length. CONCLUSIONS: Our study demonstrated that physicians integrate family systems concepts into routine individual patient care. The findings identify characteristics of the family-oriented approach and those circumstances that promote and hinder it. Family physicians can adapt specific components of the family-oriented approach into their routine individual patient care.

Dietary protein or arginine deficiency impairs constitutive and inducible nitric oxide synthesis by young rats.

Effects of dietary protein or arginine deficiency on constitutive and lipopolysaccharide (LPS)-induced nitric oxide (NO) synthesis were determined in young rats by quantifying urinary nitrate excretion. In Experiment 1, 30-d-old rats (n = 16) were divided randomly into two groups (n = 8/group) and pair-fed on the basis of body weight semipurified isocaloric diets containing 20 or 5% casein. In Experiment 2, 30-d-old rats (n = 24) were divided randomly into three groups (n = 8) and pair-fed on the basis of body weight purified isonitrogenous and isocaloric diets (composed of amino acids) containing 0.0, 0.3 or 1.0% L-arginine. In both experiments, daily collection of urine was initiated 10 d after the start of pair-feeding. On d 17 after the pair-feeding was initiated, LPS (1 mg/kg body wt) was injected intraperitoneally into rats, and urine was collected daily for an additional 7 d. In Experiments 3 and 4, activities of constitutive and inducible NO synthases were measured in macrophages and various tissues from protein- or arginine-deficient rats (n = 6). Body weight was lower in rats fed the 5% casein diet or the 0.0 and 0.3% arginine diets than in those fed 20% casein or 1% arginine, respectively. Dietary protein or arginine deficiency decreased serum concentrations of arginine and urinary nitrate excretion before and after LPS treatment, indicating impaired constitutive and inducible NO synthesis. Protein malnutrition reduced constitutive and inducible NO synthase activities in brain, heart, jejunum, lung, skeletal muscle and spleen, and inducible NO synthase activity in macrophages. Because NO is a mediator of the immune response and is the endothelium-dependent relaxing factor, impaired NO synthesis may help explain immunodeficiency and cardiovascular dysfunction in protein- or arginine-deficient subjects.

Unusual abundance of arginine and ornithine in porcine allantoic fluid.

The concentrations of free arginine, ornithine, and glutamine in porcine allantoic and amniotic fluids were determined on Days 30,35, 40, and 45 of gestation. Arginine and ornithine were the most abundant amino acids in allantoic fluid on Days 35-40 and 45 of gestation, respectively. Arginine and ornithine nitrogen accounted for 40%, 50%, and 55% of the total free alpha-amino acid nitrogen in allantoic fluid on Days 35, 40, and 45 of gestation, respectively. Glutamine was the most abundant amino acid in amniotic fluid during early gestation and was also abundant in allantoic fluid. On Day 45 of gestation, glutamine nitrogen accounted for 41% of the total free alpha-amino acid nitrogen in amniotic fluid. The unusual abundance of arginine (2.5-4.1 mM) and ornithine (1.08-2.52 mM) in allantoic fluid on Days 35-40 of gestation has not been reported for any other biological fluid. These results are novel and interesting with respect to the role of these two basic amino acids in fetal-placental nutrition and metabolism.

Maternal dietary protein deficiency decreases nitric oxide synthase and ornithine decarboxylase activities in placenta and endometrium of pigs during early gestation.

Little is known about the mechanism responsible for retarded placental and fetal growth induced by maternal dietary protein malnutrition. On the basis of the recent finding that nitric oxide (NO) and polyamines (products of L-arginine) play an important role in embryonic and placental development, the present study was designed to determine whether protein deficiency decreases placental and endometrial activities of NO synthase (NOS) and ornithine decarboxylase (ODC) (the first and key regulatory enzyme in polyamine synthesis). Primiparous gilts selected genetically for low or high plasma total cholesterol concentrations (low line and high line, respectively) were mated and then fed 1.8 kg/d of isocaloric diets containing 13% or 0.5% crude protein. At d 40 or 60 of gestation, they were hysterectomized, and placenta and endometrium were obtained for incubations, NOS and ODC assays, and measurements of free amino acids and polyamines. Maternal dietary protein restriction decreased arginine and ornithine concentrations, constitutive and inducible NOS activities and NO production, as well as ODC activity and polyamine concentrations in placenta and endometrium of both lines of gilts. Placental NO synthase activity and NO generation were lower in high line gilts than in low line gilts. ODC activities and polyamine concentrations in placenta and endometrium were decreased at d 60 compared with d 40 of gestation. These changes in placental and endometrial synthesis of NO and polyamines during early gestation may be a mechanism responsible for reduced placental and fetal growth in protein-deficient gilts and for altered conceptus development in high line gilts.