Quantifying manganese in lymphocytes to assess manganese nutritional status

To clarify whether manganese nutritional status is better reflected by the manganese concentration in lymphocytes or in whole blood, we injected manganese solutions intravenously into manganese-deficient rats and determined manganese concentrations in lymphocytes, whole blood, and various tissues. The manganese concentrations in lymphocytes and tissues, but not in whole blood, were significantly less in manganese-deficient rats than in normal rats. These low values could be prevented by intravenous injection of manganese in a dose-dependent manner. These results suggest that, for assessment of manganese nutritional status, measurement of manganese in lymphocytes is better than that in whole blood.     

An introduction to blood gas analysis

Blood gas analysis is a procedure that is associated with high dependency, intensive care and respiratory units, but equipment used to carry out blood gas analysis is now commonplace on hospital wards and in some community services. It is, therefore, important for nurses in primary and secondary care to understand the significance of blood gas analysis.     

Pulse wave analysis to assess systemic blood flow during mechanical biventricular support

Measurement of systemic blood flow is of crucial importance in patients on mechanical circulatory support (MCS). We reported the case of a 65-year-old female patient in severe cardiogenic shock undergoing left (Jarvik 2000 axial flow pump) and right (Levitronix-Centrimag centrifugal pump) ventricular assist device implant. Evaluation of blood flow was obtained by ultrasonic flowmetry, continuous thermodilution technique, and pressure recording analytical method (PRAM). This pulse contour system allows beat-by-beat systemic blood flow assessment from the analysis of radial artery pressure waveform. At a Jarvik pump speed < or = 10000 rotations per minutes (rpm), thermodilution and PRAM showed similar blood flow values. At a Jarvik pump speed > or = 11000 rpm, the aortic valve did not open and PRAM did not provide blood flow values due to nonpulsatile blood flow. The present paper describes the first experience with PRAM in a single patient on MCS. Further studies are required to assess the validity of PRAM as an additional monitoring system in the setting of ventricular assist device support.     

How to assess the risk of HIV exposure

The physician must screen patients for risk of exposure to the human immunodeficiency virus (HIV). This requires direct and specific questioning about blood product exposure, sexual practices and use of intravenous drugs. If risk factors are uncovered, patients must then be counseled on how to minimize their risk. The screening process is potentially uncomfortable for both the physician and the patient. However, intensive educational efforts, including behavioral changes, are necessary to reduce the number of HIV-infected individuals.     

Rapid radiometric assay used to assess lactoferrin in granulocytes

We describe a rapid, precise, and sensitive radiometric assay for human lactoferrin. In this typical "sandwich"-type assay, anti-human lactoferrin is adsorbed onto a polystyrene sphere and bound lactoferrin is detected by the subsequent binding of 125I-labeled anti-human lactoferrin. The assay is accurate for lactoferrin concentrations of 5 to 1500 micrograms/L and takes about 2.5 h to complete. The within-assay and interassay variations (CV) are 5% and 13%, respectively. Neither lysozyme nor heparin, substances that form complexes with lactoferrin, interfered with lactoferrin measurement by this method. The assay has been applied to the measurement of lactoferrin in polymorphonuclear leukocytes of both healthy adults and neonates. We found significantly (p less than 0.001) less lactoferrin in the latter, an abnormality that may be related to known functional deficits of polymorphonuclear leukocytes during the newborn period.     

Micronuclei in cord blood lymphocytes as a biomarker of transplacental exposure to environmental pollutants

Exposure to environmental pollutants can result in chromosomal instability, which can produce a wide variety of effects on human health. In the spring of 1999, extensive environmental pollution happened in Kragujevac (the city in the central Serbia) with damages of soil, water and air, caused by the air strikes on "Zastava" complex. Because we found significant increase of micronuclei in newborns born 12 months after this environmental pollution (in the beginning of 2000), the purpose of the present study was to follow the frequency of micronuclei in lymphocytes of newborns born seven years after pollution (in 2006). The frequencies of micronuclei were estimated in cord blood lymphocytes of 41 newborns (20 males and 21 females) by application of cytokinesis-block (CB) micronucleus test. The obtained results showed that the mean value of micronuclei was significantly decreased in newborns born in 2006 in comparison to the mean value of micronuclei in newborns born 12 months after contamination (4.73 +/- 3.38 micronuclei/1,000 CB cells vs 9.36 +/- 5.60 micronuclei/1,000 CB cells), with probability p < 0.001. Newborn's gender, mother's age (19-40 years) and maternal cigarette smoking (< 20 cigarettes per day) did not show any noticeable effects on micronuclei frequencies in the analyzed newborns. There was relationship between the micronuclei frequencies and the level of environmental pollution (F = 6.95, p = 0.000). Our results suggest that the environment profoundly influences genetic constitution of newborns, and that micronucleus assay in cord blood lymphocytes is an important method for evaluation of transplacental mutagens.     

A pharmacokinetic simulation study to assess the performance of a sparse blood sampling approach to quantify early drug exposure

Estimating early exposure of drugs used for the treatment of emergent conditions is challenging because blood sampling to measure concentrations is difficult. The objective of this work was to evaluate predictive performance of two early concentrations and prior pharmacokinetic (PK) information for estimating early exposure. The performance of a modeling approach was compared with a noncompartmental analysis (NCA). A simulation study was performed using literature‐based models for phenytoin (PHT), levetiracetam (LEV), and valproic acid (VPA). These models were used to simulate rich concentration‐time profiles from 0 to 2 h. Profiles without residual unexplained variability (RUV) were used to obtain the true partial area under the curve (pAUC) until 2 h after the start of drug infusion. From the profiles with the RUV, two concentrations per patient were randomly selected. These concentrations were analyzed under a population model to obtain individual population PK (PopPK) pAUCs. The NCA pAUCs were calculated using a linear trapezoidal rule. Percent prediction errors (PPEs) for the PopPK pAUCs and NCA pAUCs were calculated. A PPE within ±20% of the true value was considered a success and the number of successes was obtained for 100 simulated datasets. For PHT, LEV, and VPA, respectively, the median value of the success statistics obtained using the PopPK approach of 81%, 92%, and 88% were significantly higher than the 72%, 80%, and 67% using the NCA approach (p < 0.05; Mann–Whitney U test). This study provides a means by which early exposure can be estimated with good precision from two concentrations and a PopPK approach. It can be applied to other settings in which early exposures are of interest.

Study Highlights

• WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC?

Conducting pharmacokinetic (PK) studies with intensive sampling in emergent conditions like status epilepticus is challenging. Hence, getting a reliable estimate of early drug exposure to correlate with treatment response in order to develop exposure‐response relationships is difficult.

• WHAT QUESTION DID THIS STUDY ADDRESS?

The results obtained in this simulation study support the notion that a two‐sample approach can be used to estimate early drug exposure. The population PK (PopPK) approach was found to be superior in estimating early exposure as compared with the standard noncompartmental analysis (NCA) approach.

• WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE?

This PK simulation study shows that using prior information based on the PopPKs of the drug and just two plasma concentration measures per patient in the first 2 h post drug administration, it is possible to adequately estimate early drug exposure. The study not only provides an alternative method to estimate early exposure but also demonstrates that it is superior to the standard NCA approach.

• HOW MIGHT THIS CHANGE CLINICAL PHARMACOLOGY OR TRANSLATIONAL SCIENCE?

This study provides a means by which early exposure can be estimated with good precision using limited sampling. This approach can be applied to any setting in which early exposures are of interest and these exposures can be related to outcomes of interest in clinical and translational pharmacology.     

Pathways for continence care: an audit to assess how they are used

This is a follow-up article to three articles that were published between 2000 and 2001 in the British Journal of Nursing about the development of template pathways for continence care (Bayliss et al, 2000a,b, 2001). It reports on what has happened since the development of these templates. One hundred and forty-four healthcare professionals working in the field of continence care were asked to complete a questionnaire about whether the pathways are being used and what changes have been made to them. The audit found nearly half of the respondents are currently using the pathways and find them an effective method of assessing incontinence and providing equitable quality of care for patients. Many respondents have made changes to the pathways, making them easier to use and adapting them to local practice and the availability of local resources. This was what was anticipated, although the authors noted that variance tracking, which should be the driver for change, had not significantly influenced local pathways. Of those healthcare professionals not using pathways, all said they were still interested in using them, which is particularly encouraging as pathways are promoted in 'Guidelines for Continence Care' (Department of Health, 2000). To provide support to these individuals and encourage the efforts of those already using the pathways, a support group is to be established following a further conference on pathways for continence care later this year. It will be the role of this group to facilitate information sharing on pathway development. As a first step in the dissemination of information, a pack is being produced comprising consolidated versions of the changes to the pathways used in practice all over the country.     

A critique of the methods used to assess leucocyte behaviour

Methods for assessing the adhesive and locomotory properties of leucocytes are reviewed critically and a suggestion made as to the best strategy for testing an unknown compound on leucocyte behaviour. In particular the distinction is made between reductionist assays, where a single property is being investigated, and realistic assays where an attempt is made to mimic the situation in vivo. The realistic assays are often difficult (or impossible) to interpret in behavioural terms, because more than one cell activity is involved, but such assays (e.g. simple Boyden chambers), used with caution, may be preferable for initial screening, If effects are obvious in an assay of this type then more complex reductionist assays, to determine the cause of the altered behaviour, can be tried. In discussing adhesion, data from a flow-chamber system is presented to show the very rapid changes in adhesiveness when cells encounter an immune complex-coated surface. A fully automated tracking system for obtaining speed and persistence parameters for neutrophils is described, and some of the problems involved in estimating these parameters are illustrated. Movement of neutrophils in collagen gels provides a more realistic model of the environment in which they must operate in vivo, and the effects of incorporating immune complexes into such gels are reported.     

Measuring infant exposure to environmental tobacco smoke

Methods to measure infant exposure to environmental tobacco smoke (ETS) are needed to identify infants at highest risk for ETS-related health problems. The purpose of this study was to validate measures sensitive to changes in levels of infant exposure to ETS and to develop a predictive model of infant exposure to ETS. Fifteen infants of smoking mothers were followed from birth to 6 weeks of age. Exposure to ETS was measured by using a smoking habits questionnaire, cigarette "butt" collection, infant urine nicotine and cotinine levels, and ambient nicotine (personal air monitors). The 24-hour cigarette butt collection was the best predictor of acute (adjusted r2 = .83) and chronic exposure (adjusted r2 = .47) measured by infant urinary nicotine and cotinine levels when the infants were 2 weeks of age. Including scores on the smoking habits questionnaire and ambient nicotine levels increased the adjusted r2 to .88 and .61, respectively.     

Effect of specimen storage conditions on newborn dried blood spots used to assess Toxoplasma gondii immunoglobulin M (IgM)

BackgroundNewborn screening programs store—under varying conditions—residual dried blood spots (DBS). Residual DBS were used to investigate the contribution of congenital infection with Toxoplasma gondii to the etiology of hydrocephalus and as a key step, we assessed the effect of storage conditions on the stability of newborn screening biomarkers.MethodsInfants with hydrocephalus (410 cases) were identified using population-based birth defects surveillance systems in California, North Carolina, and Texas. Infants without birth defects (448 controls) were randomly selected from the same geographic areas and time periods. California stores DBS with controlled temperature, while North Carolina and Texas store DBS under ambient conditions. After removal of personal identifiers, DBS were tested for Toxo-specific immunoglobulin-M (Toxo-IgM). Because of poor elution of DBS stored in ambient conditions, additional biomarkers were tested on a specimen subset.ResultsAmong 858 DBS tested, Toxo-IgM was found in 3 cases and no controls from California (N = 515) and in no specimens from North Carolina or Texas (N = 343). Among the 98 specimens tested for selected biomarkers, statistically significant differences were found for California vs. combined North Carolina and Texas DBS (thyroid stimulating hormone, phenylalanine, methionine, leucine and citrulline p < 0.0001; tyrosine and valine p < 0.001).ConclusionsStorage conditions for residual DBS had an effect on the ability to extract, recover, and accurately measure Toxo-IgM and other biomarkers from the filter paper matrix.     

Can the electrical potential of acupoints be used to assess the functional state of meridians and the effects of therapeutics? An exploratory data analysis

IntroductionAcupoints have bioelectrical properties distinct from common skin. Besides the higher electrical conductivity and lower resistance, acupoints show capacitor-like properties, which can be related to their endogenous electrical potential. Traditional Chinese Medicine (TCM) postulates that meridians are physiological structures connecting acupoints and working as a conduit for the flow of two essential substances known as qi and xue. Objectives: This pilot study was focused in evaluating whether the electrical potential of acupoints can be correlated objectively to the functional properties as described by ancient Chinese medical theories, such as the theories of coupled meridians of the same phase ('elements'), and the principle of coupled points. Methods: Direct needle moxibustion on LU5 and needle dispulsion of LI4 were performed in 21 subjects. The electrical potential of each acupoint was measured with a high-resolution data acquisition system taking to reference the acupoint SP6 of the Spleen conduit. Results: The results may indicate a functional relationship between the therapeutics and the electrical potential response on the selected acupoints. These effects seem to be explainable considering the specific properties of each acupoint, the relationship between TCM phases, and the dynamics between coupled conduits. Conclusion: The evaluation of the endogenous electrical potential of acupoints and the changes caused by an external stimulus might contribute to the understanding of TCM concepts, mechanisms, and the effects of associated therapeutics. The observed phenomena encourage the systematic assessment of the functional vegetative status via skin electrophysiology and using objective measurements.     

Protecting children from exposure to environmental tobacco smoke

Children exposed to environmental tobacco smoke are at greater risk of a number of childhood ailments, especially in the pre-school years. Parents have little knowledge of the health risks of passive smoking, and strategies adopted by them to reduce ETS are often ineffective. Research has found that motivational counselling is effective in helping parents make changes (Emman et al, 2001; Greenberg et al, 1994). The aim of this project was to reduce the number of children exposed to environmental tobacco smoke in the home. The project was led by a member of the Hambleton and Richmondshire Smoke-Free Alliance.     

Using finger-toe pulse oximetry to assess arterial blood flow

National guidelines (RCN, 1998; Clinical Resource Efficiency Support Team, 1998; SIGN, 1998) suggest that an assessment of ankle brachial pressure index using Doppler ultrasound is necessary to assess arterial blood flow in patients with leg ulcers or healed ulcers. Robin Cooper describes a newer, more simple test of arterial blood flow using a pulse oximeter, and discusses the advantages and disadvantages of each method.     

Radial "high-performance" thin-layer chromatography used to assess fetal lung maturity

A radial "high-performance" thin-layer chromatographic (HPTLC) method is described by which the percentages and ratios of phosphatidylinositol, sphingomyelin, lecithin, phosphatidylethanolamine, phosphatidylglycerol, and dimethyl phosphatidylethanolamine may be determined simultaneously. An additional method for radial HPTLC determination of saturated phosphatidylcholine is described. We report results of application of these methods to greater than 2000 specimens of amniotic fluid from both diabetic and nondiabetic cases.     

Drugs used to limit blood surface interactions

Since the days of the triumvirate of aspirin, heparin, and warfarin, health care practitioners have attempted to blunt the response of the coagulation system. Use of CPB has enhanced our awareness of the effects that a foreign surface has on blood in general. Success in correcting or preventing life-threatening conditions caused by thromboembolic disease depends on having the ability to correct the condition as well as the ability to limit the body's response to the intervention. Knowing how the body responds to foreign surfaces is crucial, as is awareness of current methods to limit these responses. This approach will help ensure procedural success with fewer side effects and better overall patient outcomes.     

An office laboratory panel to assess vaginal problems

In determining the cause of vaginal complaints, the routine use of four simple tests ("the vagina panel") enables the physician to identify pathogens (Candida, Gardnerella, Trichomonas), pathologic processes (inflammation, estrogen deficiency) and, in most instances, a healthy vagina. Time and money are saved. The specimens can be collected in one minute during a pelvic examination. The panel can provide the answers to eight essential questions in two minutes of observer time, with supplies costing about $2.