Adherence of Candida albicans to oral epithelial cells differentiated by Papanicolaou staining

OBJECTIVE

To examine the relative adherence of Candida albicans to oral epithelial cells differentiated by Papanicolaou staining.

METHODS

Oral epithelial cells were collected from 10 healthy adults (five male, five female) and counted. Equal volumes of oral epithelial cells and candida were mixed and incubated. The epithelial cells from this mix were collected by filtration through 10 microns polycarbonate membrane filters. Cells retained on the membrane filters were stained with crystal violet followed by Papanicolaou stain. The number of yeast attached to each of 100 red, orange, and green staining oral epithelial cells was determined by direct microscopic examination.

RESULTS

C albicans had a higher level of adherence (p < 0.001) to red staining oral epithelial cells (mean (SD) number of candida attached to 100 oral epithelial cells 562 (159)) than to cells staining either orange (105 (47)) or green (161 (66)).

CONCLUSIONS

Oral epithelial cell variability for candidal adherence is confirmed. The technique provides an opportunity to examine the relation between oral epithelial cell type and oral candidosis in specific groups, such as tobacco smokers, where increased epithelial cell keratinisation and candidal colonisation has been reported.

Effect of environmental haemin upon the physiology and biochemistry of Prevotella intermedia R78

The effect of environmental haemin on the physiology and biochemistry of Prevotella intermedia R78 grown in batch culture was assessed. Extent and rate of growth increased as the environmental haemin concentration was raised. In addition, cell morphology was predominantly cocco-bacillary when cultured in high haemin environments, while bacillary forms were prevalent in low haemin conditions (< 2.5 mumol l-1). Cells harvested from low haemin environments produced greater numbers of extracellular vesicles and greater amounts of peptidolytic activity, haemagglutinating potential and haemin binding activity when compared with cells harvested from high haemin conditions. The results of the present study indicate that aspects of the biochemistry and physiology of P. intermedia are influenced by changes in environmental haemin levels.

The differential risk of oral contraceptives: the impact of full exposure history

Previous discussions have indicated that the small increases of risk of venous thromboembolism (VTE) associated with newer combined oral contraceptives (third generation, containing desogestrel and gestodene) may be attributed to bias due to cohort effects. In a case-control analysis, this may produce an overestimate of risk of newer preparations. In 10 centres in Germany and the UK, the Transnational Study analysed data from 502 women aged 16-44 years with VTE, and from 1864 controls matched for 5-year age group and region. Information on lifetime exposure history from all subjects was added to the dataset used in previous analyses and entered into a Cox regression model with time-dependent covariates. Based on 17 622 continuous exposure episodes comprising 47 914 person-years of observation, the adjusted hazard ratio (equivalent to odds ratio, OR) of VTE for the comparison of current users of third-generation versus current users of second-generation (primarily levonorgestrel compounds) combined oral contraceptives was 0.8 (0.5 to 1.3). The OR obtained in standard case-control analysis had been 1.5 (1.1 to 2.1). Adjustment for past exposures includes more information and appears more valid than the standard cross-sectional analysis. Using this approach, the Transnational Study data show no evidence for an increased risk of VTE with third- compared with second-generation combined oral contraceptives.

Social control in personal relationships: impact on health behaviors and psychological distress

This study examines associations among social control, health behavior change, and psychological distress. Social control refers to interactions between social network members that entail regulation, influence, and constraint. Social control is predicted to have dual effects leading to better health practices while also arousing psychological distress. A random sample of 242 individuals answered questions about health practices, overall exposure to social control in their networks, and social control attempts made by a specific network member. Analyses yielded mixed support for the hypotheses, but analyses of responses to the social control attempts of a specific network member did reveal that social control predicted less health-compromising behavior and more health-enhancing behavior as well as more distress. The results suggest that social control warrants greater attention in efforts to understand how personal relationships influence health.

Seizures following renal transplantation in childhood

Few studies have investigated the incidence of seizures following renal transplantation in childhood. The aim of this study was to determine this incidence and to identify risk factors. Retrospective casenote analysis was carried out on 119 transplants performed in 109 children over 10 years. Twenty-one transplants (in 20 children) were complicated by seizures, the majority of which occurred in the first 55 days after transplantation. Seizures were more common in the 5- to 10-year-old age group (P=0.03), but were no more common in those with a prior history of seizure (P=0.69). Their aetiology was predominantly multifactorial; hypertension (n=15), fever/infection (n=4) and acute allograft rejection (n=6) were commonly identified risk factors; 2 were secondary to intracerebral pathology. Most seizures were short lived, required minimal therapy and had a good long-term neurological outcome. In conclusion, seizures are relatively common following paediatric renal transplantation. Parents are now routinely counselled of this risk.

Circulating vascular endothelial growth factor is not increased during relapses of steroid-sensitive nephrotic syndrome

BACKGROUND

An uncharacterized circulating factor that increases vascular permeability has previously been described in childhood steroid-sensitive nephrotic syndrome (SSNS). The aim of this study was to determine whether this factor is vascular endothelial growth factor (VEGF), the recently described endothelial cell mitogen and enhancer of vascular permeability.

METHODS

Plasma and urine VEGF levels were measured in children with SSNS in both relapse and remission and in normal age- and sex-matched controls. Semiquantitative reverse transcriptase-polymerase chain reaction studies investigating VEGF mRNA expression were performed on peripheral blood mononuclear cells isolated from children with SSNS in relapse and controls. In two experimental models (one-hour and three-day follow-up postinfusion), Sprague-Dawley rats were intravenously administered 50 microg rVEGF to determine whether this induced either proteinuria or glomerular histologic change.

RESULTS

Plasma VEGF levels and urine VEGF/creatinine ratios were not elevated in SSNS relapse compared with remission and control samples. Peripheral blood mononuclear cell VEGF mRNA expression was no different in SSNS patients compared with controls. The administration of VEGF to rats induced an acute reversible fall in systemic blood pressure but did not result in the development of either proteinuria or glomerular histologic change.

CONCLUSION

Increased circulating VEGF levels are not responsible for the proteinuria observed during relapses of SSNS. Further studies are warranted to investigate intrarenal VEGF expression.

Mannitol and frusemide in the treatment of diuretic resistant oedema in nephrotic syndrome

Three children (two girls aged 7 and 9 years, and one boy aged 4 years) with diuretic resistant oedema in steroid resistant nephrotic syndrome were treated with a combination of intravenous mannitol and frusemide. All three responded with loss of oedema of 10% to 30% of body weight over one week. There were no complications of hypertension or hypovolaemia. Mannitol-frusemide combination is a safe, inexpensive, and effective treatment for diuretic resistant oedema. Its use in other conditions and in developing countries (where the availability and purity of 20% albumin is limited) needs to be explored.

Social control in personal relationships: impact on health behaviors and psychological distress

This study examines associations among social control, health behavior change, and psychological distress. Social control refers to interactions between social network members that entail regulation, influence, and constraint. Social control is predicted to have dual effects leading to better health practices while also arousing psychological distress. A random sample of 242 individuals answered questions about health practices, overall exposure to social control in their networks, and social control attempts made by a specific network member. Analyses yielded mixed support for the hypotheses, but analyses of responses to the social control attempts of a specific network member did reveal that social control predicted less health-compromising behavior and more health-enhancing behavior as well as more distress. The results suggest that social control warrants greater attention in efforts to understand how personal relationships influence health.

Assessment of risk reduction strategies for the management of agricultural nonpoint source pesticide runoff in estuarine ecosystems

Agricultural nonpoint source (NPS) runoff may result in significant discharges of pesticides, suspended sediments, and fertilizers into estuarine habitats adjacent to agricultural areas or downstream from agricultural watersheds. Exposure of estuarine fin fish and shellfish to toxic levels of pesticides may occur, resulting in significant declines in field populations. Integrated pest management (IPM), best management practices (BMP), and retention ponds (RP) are risk management tools that have been proposed to reduce the contaminant risk from agricultural NPS runoff into estuarine ecosystems. Field studies were conducted at three sites within coastal estuarine ecosystems of South Carolina (SC) from 1985 to 1990 that varied in terms of the amount and degree of risk reduction strategies employed. An intensively managed (IPM, BMP, and RP) agricultural treatment site (TRT) was studied for pesticide runoff impacts. From 1985 to 1987, there were minimal (some IPM and BMP) management activities at TRT, but from 1988 to 1990, TRT was managed using an intensive risk reduction strategy. A second unmanaged agricultural growing area, Kiawah (KWA), was also studied and compared with TRT in terms of pesticide runoff and the resulting impacts on grass shrimp (Palaemonetes pugio) and mummichogs (Fundulus heteroclitus). A third, non-agricultural, reference site (CTL) was used for comparing results from the managed and unmanaged agricultural sites. In situ toxicity tests and field samples of the grass shrimp populations were conducted at each site and compared in terms of survival and the effectiveness of current risk reduction strategies. Significant runoff of insecticides (azinphosmethyl, endosulfan, and fenvalerate) along with several fish kills were observed at TRT prior to the implementation of rigorous risk reduction methods. A significant reduction of in stream pesticide concentrations (up to 90%) was observed at TRT following the implementation of strict NPS runoff controls, which greatly reduced impacts on estuarine fish and shellfish. At the unmanaged KWA, continued impacts due to the runoff of these insecticides were observed, along with several fish kills. Additional monitoring indicated that gravid female grass shrimp populations from KWA had elevated levels of P-glycoprotein (P-gp), a multidrug resistance protein, which may transport various pesticides across cellular membranes. Comparison of field results with laboratory toxicity tests established that pesticide exposure was the primary cause of observed field impacts at each site. These findings clearly indicate the value of an integrated risk reduction strategy (BMP, IPM, and RP) for minimizing impacts from NPS agricultural pesticide runoff.

Differences between child and parent reports of symptoms among Latino children with asthma

OBJECTIVES

To determine, in a population of predominantly Latino children with asthma 6 to 18 years old, whether parent and child reports of asthma symptoms with exercise differ and to evaluate the validity of child and parent reports of symptoms.

DESIGN

Data obtained from child and parent interviews; pulmonary function tests (forced vital capacity, forced expiratory volume in 1 second, forced expiratory flow25-75, peak expiratory flow), and observation of symptoms after exercise.

SETTING

Three summer camps for minority children with asthma in Los Angeles County.

PARTICIPANTS

A total of 97 children with asthma (78% Latino, 12% non-Latino White, 9% Other; 6 to 18 years of age) and their parents.

INTERVENTION(S)

None.

PRIMARY OUTCOME MEASURES

Child and parent reports of cough and wheezing with exercise and pulmonary function tests before and after exercise. While at camp, children underwent spirometry after completing the self-administered survey. The pulmonary function tests were conducted and interpreted according to the pediatric specifications for spirometry, and results >80% of predicted, adjusted for gender, age, height, and race, were considered normal. Six peak expiratory flow rates (PEFR) by peak flow meter also were recorded by trained research assistants immediately before spirometry, and values >80% of predicted based on height were considered normal. To observe child symptoms with exercise, children participated in a relay running race of 200 feet followed by a swimming race of 300 feet. Research assistants measured heart rate and 6 PEFRs using ASSESS portable peak flow meters immediately before and after each exercise. A positive exercise challenge was defined as a 15% reduction in mean PEFR and/or observed asthma symptoms (cough, wheezing, chest pain, asthma attack).

RESULTS

Of the children, 18% reported never having a cough when they exercised, 46% reported having it occasionally when they exercised, and 36% reported having it quite often or always when they exercised. For wheezing, 20% of children reported never having wheezing when they exercised, 35% having it occasionally when they exercised, and 45% having it quite often or always when they exercised. Parents reported fewer symptoms than did their children. Of the parents, 34% reported that their children did not have cough with exercise, 37% reported few to some days, and 29% reported most days or every day. Forty-seven percent of parents reported that their child did not wheeze with exercise in the last 2 months, 35% reported wheezing on a few days to some days, and 17% reported wheezing most days to every day. Parent and child reports of cough or wheezing after exercise correlated mildly with each other (parent/child cough r = 0. 23; kappa = 0.03; parent/child wheezing r = 0.21; kappa = 0.14). Children were more likely to report cough: 59 of 71 (83%) of children versus 44 of 71 (62%) of parents. The 22 children who reported cough when their parents did not account for most of the disagreement between parents and children. Children were more likely than were their parents to report wheezing; 55 of 69 (80%) children versus 36 of 69 (52%) parents reported that the child wheezed. The 24 children who reported wheezing when their parents did not account for most of the disagreement between parents and children. Forty-seven percent of the children had a value <80% of predicted for at least one of the four spirometry tests; 29% of mean baseline PEFRs were <80% of predicted. Overall, 86% of the children met one or more of the following: any percent of predicted pulmonary function tests <80% or any symptom or PEFR reduction of 15% after exercise, or other occurrence of nonexercise symptoms during camp. Almost all child reports of cough and wheezing correlated significantly with the criterion validity criteria. For example, child reports of wheezing were, as expected, correlated negatively with the percent of predicted FEV1 (r = -0.28) and correlated positive

Immunocytochemical detection of Candida albicans in formalin fixed, paraffin embedded material

AIM

To assess the ability of the commercially available monoclonal antibody 1B12 (BioGenex, San Ramon, USA) to identify C albicans in formalin fixed, paraffin wax embedded material (FFPE).

METHODS

Broth cultures of 20 strains of seven Candida species were resuspended in 4% agarose blocks, fixed in formalin for 24 hours, and embedded in paraffin wax. In addition, 16 blocks of FFPE tissue known to contain periodic acid-Schiff positive fungal hyphae were examined. Antigen retrieval involved microwave treatment of specimens in citrate buffer (0.01 M; pH 6.5) before addition of 1B12 antibody for 24 hours. Bound antibody was subsequently detected using a biotinylated link antibody and a peroxidase conjugated streptavidin.

RESULTS

Only C albicans strains were 1B12 positive in the agarose blocks. All FFPE tissue blocks were found to contain 1B12 positive hyphal structures, indicating the presence of C albicans.

CONCLUSIONS

The ability to identify candida organisms penetrating the lesional tissue in cases of chronic hyperplastic candidosis will help to clarify the role of individual Candida spp in this important form of oral candidosis.

SPECT electronic collimation resolution enhancement using chi-square minimization

An electronic collimation technique is developed which utilizes the chi-square goodness-of-fit measure to filter scattered gammas incident upon a medical imaging detector. In this data mining technique, Compton kinematic expressions are used as the chi-square fitting templates for measured energy-deposition data involving multiple-interaction scatter sequences. Fit optimization is conducted using the Davidon variable metric minimization algorithm to simultaneously determine the best-fit gamma scatter angles and their associated uncertainties, with the uncertainty associated with the first scatter angle corresponding to the angular resolution precision for the source. The methodology requires no knowledge of materials and geometry. This pattern recognition application enhances the ability to select those gammas that will provide the best resolution for input to reconstruction software. Illustrative computational results are presented for a conceptual truncated-ellipsoid polystyrene position-sensitive fibre head-detector Monte Carlo model using a triple Compton scatter gamma sequence assessment for a 99mTc point source. A filtration rate of 94.3% is obtained, resulting in an estimated sensitivity approximately three orders of magnitude greater than a high-resolution mechanically collimated device. The technique improves the nominal single-scatter angular resolution by up to approximately 24 per cent as compared with the conventional analytic electronic collimation measure.

The epidemiology of oral contraceptive use: a critical review of the studies on oral contraceptives and the health of young women

Recent observational studies show a slightly increased risk of venous thromboembolism among users of newer combined oral contraceptives with odds ratios between 0.8 and 2.3 when compared with users of older oral contraceptives. The controversy regarding the newer oral contraceptives is reviewed by analyzing the recent studies with epidemiologic methods. Key studies on venous thromboembolism may be subject to bias related to prescribing criteria, diagnostics, hospital referral, cohort effects, and residual confounding, resulting in an overestimate of the risk of venous thromboembolism associated with the newer oral contraceptives. The studies on stroke showed no difference between newer and older oral contraceptives, and studies on myocardial infarction show that newer oral contraceptives carry no risk of this event. Newer-generation oral contraceptives are unlikely to constitute a significant hazard to the user population with regard to venous thromboembolism. The results for other disease entities also need to be taken into account when the results on venous thromboembolism are assessed on a population basis.

Analytic treatment of resolution precision in electronically collimated SPECT imaging involving multiple-interaction gamma rays

The widely applied single-interaction analytic expression characterizing the energy resolution component of the angular resolution precision for an electronically collimated point source is extended to include multiple-interaction Compton scatter sequences as well as sequences terminated by photoelectric absorption. The analytic formulation is developed using the statistical variance of the mean for components comprising composite, multivariate resolution precision estimators. It is demonstrated that enhanced resolution precision in the incident interaction scatter angle is attained when use is made of information from multiple interactions. An improvement in the resolution precision of up to approximately 40% is observed for triple Compton scatter. Comparison of the analytic estimates with Monte Carlo/chi-square results shows good agreement.

Myocardial infarction and stroke in young women: what is the impact of oral contraceptives?

Recent discussions have centered on the small apparent risk increase for venous thromboembolism found with newer oral contraceptives (third-generation oral contraceptives containing the progestins desogestrel and gestodene) compared with older oral contraceptives (second-generation). This article reviews the studies addressing the association between oral contraceptive use and thromboembolic conditions affecting the arterial system, ischemic stroke, and myocardial infarction. Differences are found between a US database study, which showed no risk of ischemic stroke or myocardial infarction associated with low-dose oral contraceptive use, and the European studies, which showed oral contraceptive use in general to be associated with increased risks of ischemic stroke and myocardial infarction. The European studies showed no difference between oral contraceptive generations with respect to the occurrence of ischemic stroke; however, the risk of myocardial infarction associated with oral contraceptive use was consistently lower for third- than for second-generation oral contraceptives. Although there seems to be no differential risk of ischemic stroke associated with oral contraceptive generations, third-generation oral contraceptives appear to be consistently associated with no excess risk of myocardial infarction. In all instances, however, cardiovascular risk factors other than oral contraceptive use play the predominant role in the occurrence of ischemic stroke and myocardial infarction.

Chronic stress and illness in children: the role of allostatic load

OBJECTIVE

Recent studies of stress have highlighted the contributions of chronic psychological and environmental stressors to health and well-being. Children may be especially vulnerable to the negative effects of chronic stressors. Allostasis, the body's ability to adapt and adjust to environmental demands, has been proposed as an explanatory mechanism for the stress-health link, yet empirical evidence is minimal. This study tested the proposition that allostasis may be an underlying physiological mechanism linking chronic stress to poor health outcomes in school-aged children. Specifically, we examined whether allostasis would mediate or moderate the link between chronic stress and health.

METHOD

To test the hypothesis that allostasis contributes to the relation between chronic stress and poor health, we examined household density as a chronic environmental stressor, cardiovascular reactivity (CVR) as a marker of allostatic load, and number of school absences due to illness as the health outcome in a sample of 81 boys.

RESULTS

Structural equation modeling indicated that the mediating model fit the data well, accounting for 17% of the variance in days ill.

CONCLUSIONS

Results provide the first evidence that CVR may mediate the relation between household density and medical illness in children. More generally, these findings support the role of allostasis as an underlying mechanism in the link between chronic stress and health.

Atrial fibrillation and anticoagulation in patients with permanent pacemakers: implications for stroke prevention

Several large prospective randomized trials have demonstrated that anticoagulation with warfarin reduces the risk of thromboembolic stroke in high risk patients with chronic AF by approximately 70%. Large numbers of patients with permanent pacemakers have AF, and anticoagulation rates in this population have not been described. In a prospective analysis of 110 consecutive patients attending the pacemaker clinic of a large university hospital we assessed the number of patients with AF and the proportion of these patients who were receiving anticoagulation to prevent thromboembolic stroke. Where necessary, temporary pacemaker reprogramming to low ventricular rates was utilized to facilitate the diagnosis of AF. Fifty-three of the 110 patients (48%) were diagnosed with AF, all of whom (100%) had accepted high risk factors for thromboembolic stroke. Only eight of the 53 (15%) had been anticoagulated with warfarin. Thirty-six of the 53 patients (68%) diagnosed with AF had no prior documented diagnosis of chronic AF, and the majority had no symptoms suggesting AF. A single lead II ECG was insufficient in 67 of the 110 patients (61%) to diagnose the underlying atrial rhythm; the remainder required 12-lead ECGs or temporary pacemaker reprogramming to low ventricular rates to diagnose the underlying atrial rhythm. AF is common in patients with permanent pacemakers. It is commonly asymptomatic, and anticoagulation is markedly underutilized in reducing stroke risk in these patients. Attention to the possibility of AF in paced patients should allow prompt diagnosis and allow both the initiation of anticoagulation in order to reduce thromboembolic stroke risk and consideration for cardioversion of AF to sinus rhythm.

Ethical challenges in treating mother and fetus when cancer complicates pregnancy

This article evaluates the complicated scenario for physicians when they must advise pregnant oncology patients and their families. Included in this discussion are a review of literature that addresses both maternal and fetal rights and an analysis of metaphysical considerations unique to this situation. Additionally, there is a presentation of philosophical ideations, including an introduction to the ethical principles of autonomy, beneficence, and authenticity, which are offered in an attempt to increase the physician's comfort level with this very difficult task.

A novel technique for assessment of adherence of Candida albicans to solid surfaces

A novel approach for the assessment of adherence of Candida albicans to translucent acrylic material is described. The method uses the inverted microscope to visualise yeast adhering to acrylic surfaces while the test material remains immersed in buffer. Adherent cells were not subjected to surface tension forces that can occur during drying processes, so that an even distribution of yeast with no aggregation occurred. The process of counting attached yeast was subsequently performed without difficulty. From the 11 C albicans isolates examined, two groups were evident with respect to acrylic adherence: one group of four isolates with an adherence level of 400 yeast/mm2 acrylic, and one group of seven isolates with adherence levels of 1000 yeast/mm2 acrylic.

An examination of the role of learning environments in the construction of nursing identity

The interplay between the development of a nurse's identity within the world of nursing, and the construction of relevant nursing concepts is by necessity a difficult and complex one. It is in part grounded in the theories of social interaction, concept formation, and relevant peripheral participation in the workplace, all of which can be related to the nursing role. These issues are considered here primarily from the sociocultural viewpoint of Vygotsky, bringing together the important role of significant participants in the nurse's learning experiences, predominantly peers, and examining briefly the effects of such a viewpoint in relation to nursing education. How best nursing knowledge may be structured to optimize the learner's educational experiences, and how best the learning environment of the student may be utilized to maximum educational benefit still remain complex questions. With moves towards more competence-based learning such interactions may be crucial to our understanding of the complexities of learning in what are essentially very practical-based environments, and at the same time allow us to acknowledge the important mechanisms involved in concept acquisition and transferability, a notion central to lifelong learning.