Study of metalation of thioredoxin by gold(I) therapeutic compounds using combined liquid chromatography/capillary electrophoresis with inductively coupled plasma/electrospray MS/MS detection

The reactivity of thioredoxin (Trx1) with the Au(I) drug auranofin (AF) and two therapeutic N-heterocyclic carbene (NHC)2-Au(I) complexes (bis [1-methyl-3-acridineimidazolin-2-ylidene]gold(I) tetrafluoroborate (Au3BC) and [1,3-diethyl-4,5-bis(4methoxyphenyl)imidazol-2-ylidene]gold(I) (Au4BC)) was investigated. Direct infusion (DI) electrospray ionization (ESI) mass spectrometry (MS) allowed information on the structure, stoichiometry, and kinetics of formation of Trx-Au adducts. The fragmentation of the formed adducts in the gas phase gave insights into the exact Au binding site within the protein, demonstrating the preference for Trx1 Cys32 or Cys35 of AF or the (NHC)2-Au(I) complex Au3BC, respectively. Reversed-phase HPLC suffered from the difficulty of elution of gold compounds, did not preserve the formed metal-protein adducts, and favored the loss of ligands (phosphine or NHC) from Au(I). These limitations were eliminated by capillary electrophoresis (CE) which enabled the separation of the gold compounds, Trx1, and the formed adducts. The ICP-MS/MS detection allowed the simultaneous quantitative monitoring of the gold and sulfur isotopes and the determination of the metallation extent of the protein. The hyphenation of the mentioned techniques was used for the analysis of Trx1-Au adducts for the first time.

Fe3O4SPIONs in cancer theranostics-structure versus interactions with proteins and methods of their investigation

As the second leading cause of death worldwide, neoplastic diseases are one of the biggest challenges for public health care. Contemporary medicine seeks potential tools for fighting cancer within nanomedicine, as various nanomaterials can be used for both diagnostics and therapies. Among those of particular interest are superparamagnetic iron oxide nanoparticles (SPIONs), due to their unique magnetic properties,. However, while the number of new SPIONs, suitably modified and functionalized, designed for medical purposes, has been gradually increasing, it has not yet been translated into the number of approved clinical solutions. The presented review covers various issues related to SPIONs of potential theranostic applications. It refers to structural considerations (the nanoparticle core, most often used modifications and functionalizations) and the ways of characterizing newly designed nanoparticles. The discussion about the phenomenon of protein corona formation leads to the conclusion that the scarcity of proper tools to investigate the interactions between SPIONs and human serum proteins is the reason for difficulties in introducing them into clinical applications. The review emphasizes the importance of understanding the mechanism behind the protein corona formation, as it has a crucial impact on the effectiveness of designed SPIONs in the physiological environment.

MR-guided HDR prostate brachytherapy with teleoperated steerable needles

Conformity of tumour volumes and dose plans in prostate brachytherapy (BT) can be constrained by unwanted needle deflections, needle access restrictions and visualisation limitations. This work validates the feasibility of teleoperated robotic control of an active steerable needle using magnetic resonance (MR) for guidance. With this system, perturbations can be counteracted and critical structures can be circumvented to access currently inaccessible areas. The system comprises of (1) a novel steerable needle, (2) the minimally invasive robotics in an MR environment (MIRIAM) system, and (3) the daVinci Research Kit (dVRK). MR scans provide visual feedback to the operator controlling the dVRK. Needle steering is performed along curved trajectories to avoid the urethra towards targets (representing tumour tissue) in a prostate phantom with a targeting error of 1.2 ± 1.0 mm. This work shows the potential clinical applicability of active needle steering for prostate BT with a teleoperated robotic system in an MR environment.

Enhanced edible plant production using nano-manganese and nano-iron fertilizers: Current status, detection methods and risk assessment

BACKGROUND

Nanotechnology offers many benefits in the globally important field of food production and human nutrition, particularly by implementing agricultural nanoproducts. Of these, edible plant fertilizers enriched with nanosized forms of essential metals, Mn and Fe, are growing in importance with the advantages of enhanced action on plant roots.

SCOPE AND APPROACH

This review focuses on the importance of tracking the bioaccumulation and biodistribution of these pertinent nanofertilizers. An emphasis is given to the critical analysis of the state-of-the-art analytical strategies to examine the Mn and Fe nanoparticles in edible plant systems as well as to shedding light on the vast gap in the methodologies dedicated to the speciation, in vitro simulation, and safety testing of these promising nanomaterials. Also provided are guidances for the food chemists and technologists on the lights and shadows of particular analytical approaches as a matter of authors' expertise as analytical chemists.

KEY FINDINGS AND CONCLUSIONS

While the use of nanotechnology in agriculture seems to be growing increasingly, there is still a lack of analytical methodologies capable of investigating novel Mn- and Fe-based nanomaterials as potential fertilizers. Only the advent of reliable analytical tools in the field could bridge the gaps in our knowledge about processes in which those materials participate in the plant systems and their effects on crop production and quality of the produced food.

Red Flags and Adversities on the Way to the Robust CE-ICP-MS/MS Quantitative Monitoring of Self-Synthesized Magnetic Iron Oxide(II, III)-Based Nanoparticle Interactions with Human Serum Proteins

The growing interest in superparamagnetic iron oxide nanoparticles (SPIONs) as potential theranostic agents is related to their unique properties and the broad range of possibilities for their surface functionalization. However, despite the rapidly expanding list of novel SPIONs with potential biomedical applications, there is still a lack of methodologies that would allow in-depth investigation of the interactions of those nanoparticles with biological compounds in human serum. Herein, we present attempts to employ capillary electrophoresis-inductively coupled plasma tandem mass spectrometry (CE-ICP-MS/MS) for this purpose and various obstacles and limitations noticed during the research. The CE and ICP-MS/MS parameters were optimized, and the developed method was used to study the interactions of two different proteins (albumin and transferrin) with various synthesized SPIONs. While the satisfactory resolution between proteins was obtained and the method was applied to examine individual reagents, it was revealed that the conjugates formed during the incubation of the proteins with SPIONs were not stable under the conditions of electrophoretic separation.

Protein-Mediated Transformations of Superparamagnetic Nanoparticles Evidenced by Single-Particle Inductively Coupled Plasma Tandem Mass Spectrometry: A Disaggregation Phenomenon

Progress toward translating superparamagnetic iron oxide nanoparticles (SPIONs) with specific diagnostic and therapeutic properties for clinical applications depends on developing and implementing appropriate methodologies that would allow in-depth characterizations of their behavior in a real biological environment. Herein, we report a versatile approach for studying interactions between SPIONs and proteins using single-particle inductively coupled plasma tandem mass spectrometry. By monitoring the changes in the size distribution upon exposure to human serum, the formation of stable protein corona is revealed, accompanied by particle disaggregation.

Simple Ultraviolet-Visible Spectroscopy-Based Assay for Fast Evaluation of Magnetic Nanoparticle Selectivity Changes After Doping

Simple ultraviolet-visible spectroscopy-based methodology was proposed and utilized for the initial characterization of potential changes in selectivity of doped magnetic nanoparticles. Doped and undoped iron(II,III) (Fe₃O₄) magnetic nanoparticles were synthesized by the coprecipitation method. The doping processes of nanoparticles were confirmed using optical emission spectrometry, while the sizes of undoped and Cu-doped nanoparticles were investigated using a high-resolution field emission scanning electron microscope. The average diameters of nanoparticles were 8.34±1.78 nm and 9.12±1.93 nm, for doped and undoped materials, respectively. The influence of the nanoparticle's doping on their selectivity towards chosen analyte was monitored by the spectral techniques such as ultraviolet-visible and optical emission spectrometry. The interaction between Cu-doped Fe₃O₄ nanoparticles and cuprizone (a compound forming the characteristic colorful complex with copper) was confirmed. The elaborated studies proved the potential of ultraviolet-visible spectroscopy for the fast qualification of magnetic nanoparticles in terms of their ability to separate the selected analyte from the sample matrix.

A CE-ICP-MS/MS method for the determination of superparamagnetic iron oxide nanoparticles under simulated physiological conditions

Over the past few years, superparamagnetic iron oxide nanoparticles (SPIONs) have attracted much attention due to their medicinally attractive properties and their possible application in cancer diagnosis and therapy. However, there is still a lack of appropriate methods to enable quantitative monitoring of the particle changes in a physiological environment, which could be beneficial for evaluating their in vitro and in vivo behavior. For this reason, the main goal of this study was the development of a novel capillary electrophoresis-inductively coupled plasma mass spectrometry (CE-ICP-MS/MS) method for the determination of SPIONs suitable for the future examination of their changes upon incubation with proteins under simulated physiological conditions. The type and flow rate of the collision/reaction gas were chosen with the aim of simultaneous monitoring of Fe and S. The type and concentration of the background electrolyte, applied voltage, and sample loading were optimized to obtain SPION signals of the highest intensity and minimum half-width of the peak. Analytical parameters were at a satisfactory level: reproducibility (intra- and inter-day) of migration times and peak areas (presented as RSD) in the range of 0.23-4.98%, recovery: 96.7% and 93.3%, the limit of detection (for monitoring 56Fe16O+ by mass-shift approach) 54 ng mL-1 Fe (0.97 μM) and 101 ng mL-1 Fe (1.82 μM) for SPIONs with carboxyl and amino terminal groups, respectively. To the best of our knowledge, this is the first reported use of CE-ICP-MS/MS for the quantification of SPIONs and monitoring of interactions with proteins.

Comment on: "A novel approach to peatlands as archives of total cumulative spatial pollution loads from atmospheric deposition of airborne elements complementary to EMEP data: Priority pollutants (Pb, Cd, Hg)" by Ewa Miszczak, Sebastian Stefaniak, Adam Michczyński, Eiliv Steinnes and Irena Twardowska

A recent paper by Miszczak et al. (2020) examines metal contamination of mires in Poland and Norway. The authors conclude that lead (Pb) records in ombrotrophic peatlands cannot be used to reconstruct the chronological history of anthropogenic activities due to post-depositional mobility of the metal. We contest this general conclusion which stands in contrast with a significant body of literature demonstrating that Pb is largely immobile in the vast majority of ombrotrophic peatlands. Our aim is to reaffirm the crucial contribution that peat records have made to our knowledge of atmospheric Pb contamination. In addition, we reiterate the necessity of following established protocols to produce reliable records of anthropogenic Pb contamination in environmental archives.

Support for breastfeeding mothers

BACKGROUND

Both observational and recent experimental evidence support the promotion of breastfeeding as the optimal form of infant nutrition. There is, however, uncertainty as to the most effective way of providing support to women who choose to breastfeed their children. A systematic review was performed to describe studies undertaken in this area and to assess the effectiveness of supplementary support.

OBJECTIVES

The objective of this review was to assess the effects of breastfeeding support.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group trials register, the Cochrane Controlled Trials Register, MEDLINE and EMBASE. These were last searched in March 2001. Secondary references were searched and researchers in the field were contacted.

SELECTION CRITERIA

Controlled trials of acceptable quality comparing extra support for breastfeeding mothers with usual maternity care.

DATA COLLECTION AND ANALYSIS

Data were extracted by one reviewer and checked by a second reviewer.

MAIN RESULTS

Twenty eligible randomised or quasi-randomised controlled trials from 10 countries were identified involving 23,712 mother-infant pairs. There was a beneficial effect on the duration of any breastfeeding in the meta-analysis of all forms of extra support (relative risk (RR) for stopping any breastfeeding before six months 0.88 [95% confidence interval (CI) 0.81,0.95]; 15 trials, 21,910 women). The effect was greater for exclusive breastfeeding (RR 0.78 [95% CI 0.69,0.89]; 11 trials, 20,788 women). Extra professional support appeared beneficial for any breastfeeding (RR 0.89 [95% CI 0.81,0.97]; 10 trials, 19,696 women) and for exclusive breastfeeding (RR 0.90 [95% confidence interval 0.81,1.01]; six trials, 18,258 women) although the latter effect did not achieve full statistical significance. Lay support was effective in reducing the cessation of exclusive breastfeeding (RR 0.66 [95% CI 0.49,0.89]; five trials, 2530 women) but its effect on any breastfeeding did not reach statistical significance (RR 0.84 [95% CI 0.69,1.02]; five trials, 2224 women). Professional support in the largest trial to assess health outcomes produced a significant reduction in the risk of gastro-intestinal infections and atopic eczema. In two trials with children suffering from diarrhoeal illness extra support was highly effective in increasing short term exclusive breastfeeding rates and reducing recurrence of diarrhoea.

REVIEWER'S CONCLUSIONS

Consideration should be given to providing supplementary breastfeeding support as part of routine health service provision. There is clear evidence for the effectiveness of professional support on the duration of any breastfeeding although the strength of its effect on the rate of exclusive breastfeeding is uncertain. Lay support is effective in promoting exclusive breastfeeding while the strength of its effect on the duration of any breastfeeding is also uncertain. Evidence supports the promotion of exclusive breastfeeding as central to the management of diarrhoeal illness in partially breastfed infants. Further trials are required to assess the effectiveness (including cost-effectiveness) of both lay and professional support in different settings - in particular in those communities with low rates of breastfeeding initiation. Research is also required into the most appropriate training for those, whether lay or professional, who support breastfeeding mothers.

Pseudomonas kilonensis sp. nov., a bacterium isolated from agricultural soil

A total of 131 bacterial isolates related to Pseudomonas corrugata were obtained from an agricultural soil from northern Germany. Based on 16S rRNA gene sequences, PCR-based genome fingerprinting and multilocus enzyme electrophoresis, they formed two groups, A (119 strains) and B (12 strains). As members of each group were highly similar, a single strain of each group was subsequently characterized by a polyphasic taxonomic approach. The selected member of group A was identified as a strain of Pseudomonas brassicacearum, whereas the selected member of group B was distinct from other species of the genus Pseudomonas. Although DNA-DNA hybridization suggested a close affiliation of the group B strain with P. brassicacearum and Pseudomonas thivervalensis and ribotyping suggested a close affiliation with P. brassicacearum, RAPD data, 16S rRNA gene sequencing and phenotypic characterization indicated the presence of a distinct taxonomic entity. This strain differed from the type strains of P. thivervalensis and P. brassicacearum in 10 and 12 metabolic properties, respectively, whereas the two organisms differ from one another by only two properties. Strains of group B are therefore considered to be members of a new species, for which the name Pseudomonas kilonensis sp. nov. is proposed. The type strain is strain 520-20T (= DSM 13647T = CFBP 5372T).

Prevalence of breastfeeding at four months in general practices in south London

BACKGROUND

Successive quinquennial National Infant Feeding Surveys have provided a valuable picture of national and regional variations in infant feeding practices within the United Kingdom. Social variation in breastfeeding has been recognised to be an important source of health inequalities in childhood by the Independent Inquiry into Inequalities in Health Report.

AIM

To determine the prevalence of breastfeeding at birth and at four months in a sample of women from urban general practices, its variation between practices, and relation to practice population deprivation scores. To report the timing of introduction of solid feeds.

DESIGN OF STUDY

Cross-sectional questionnaire survey based on a random cluster sample.

SETTING

Women with infants aged four months in general practices in South London.

METHOD

Mode of infant feeding at birth and four months, and time of introduction of solids. Jarman score as a measure of practice population deprivation. Housing tenure, maternal ethnic group, and maternal age at leaving full-time education.

RESULTS

Twenty-five general practices were sampled. Median practice Jarman score was 15.0 (interquartile range [IQR] = 12.6-21.9). Responses were received from 1053 out of 1532 mothers approached (69%). Of these, 87% (897) had breastfed at birth, while 59% (609) were still breastfeeding their babies at four months. Mothers in rented accommodation were less likely to breastfeed than owner-occupiers (odds ratio [95% CI] = 0.52 [0.37-0.74]), as were women of white, compared with those of black, ethnic origin (odds ratio [95% CI] = 0.55 [0.36-0.82]). Those who completed up to two years and more than two years education after the age of 16 were 2.94 (95% CI = 1.85-4.66) and 9.25 (95% CI = 6.02-14.21) more likely to breastfeed at four months, respectively, than mothers whose formal education was completed at or before 16 years. Practice-specific rates of breastfeeding ranged from 71% to 100% at birth (median 87%; IQR = 79-93%) and 22% to 83% at four months (median 61%; interquartile range = 47-66%). The intra-practice correlation coefficient for breastfeeding at four months was 0.052 (within-cluster variance = 0.23, between-cluster variance = 0.013). There was no association between breastfeeding at four months and practice-specific Jarman score. Median age of starting solids was 16 weeks (IQR = 15-17 weeks).

CONCLUSIONS

Housing tenure, maternal education, and ethnic group are significantly associated with breastfeeding prevalence at four months. Between-practice variation in breastfeeding prevalence is not associated with measures of practice population deprivation, as assessed by Jarman scores. Consideration should be given to including information on maternal ethnic group and housing tenure in future National Infant Feeding Surveys. Current weaning practices fall short of the recommendation of the World Health Assembly.

The structure of a local population of phytopathogenic Pseudomonas brassicacearum from agricultural soil indicates development under purifying selection pressure

Among the isolates of a bacterial community from a soil sample taken from an agricultural plot in northern Germany, a population consisting of 119 strains was obtained that was identified by 16S rDNA sequencing and genomic fingerprinting as belonging to the recently described species Pseudomonas brassicacearum. Analysis of the population structure by allozyme electrophoresis (11 loci) and random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR; four primers) showed higher resolution with the latter method. Both methods indicated the presence of three lineages, one of which dominated strongly. Stochastic tests derived from the neutral theory of evolution (including Slatkin's exact test, Watterson's homozygosity test and the Tajima test) indicated that the population had developed under strong purifying selection pressure. The presence of strains clearly divergent from the majority of the population can be explained by in situ evolution or by influx of strains as a result of migration or both. Phytopathogenicity of a P. brassicacearum strain determined with tomato plants reached the level obtained with the type strain of the known pathogen Pseudomonas corrugata. The results show that a selective sweep was identified in a local population. Previously, a local selective sweep had not been seen in several populations of different bacterial species from a variety of environmental habitats.

An economic evaluation comparing two schedules of antenatal visits

OBJECTIVES

To conduct an economic evaluation comparing a traditional antenatal visiting schedule (traditional care) with a reduced schedule of visits (new style care) for women at low risk of complications.

METHODS

Economic evaluation using the results of a randomised controlled trial, the Antenatal Care Project. This took place between 1993 and 1994 in antenatal clinics in South East London and involved 2794 women at low risk of complications.

RESULTS

The estimated baseline costs to the UK National Health Service (NHS) for the traditional schedule were 544 Pounds per woman, of which 251 Pounds occurred antenatally, with a range of 327-1203 Pounds per woman. The estimated baseline costs to the NHS for the reduced visit schedule was 563 Pounds per woman, of which 225 Pounds occurred antenatally, with a range of 274-1741 Pounds per woman. Savings from new style care that arose antenatally were offset by the greater numbers of babies in this group who required special or intensive care. Sensitivity analyses based on possible variations in unit costs and resource use and modelled postnatal stay showed considerable variation and substantial overlap in costs.

CONCLUSIONS

Patterns of antenatal care involving fewer routine visits for women at low risk of complications are unlikely to result in savings to the Health Service. In addition, women who had the reduced schedule of care reported greater dissatisfaction with their care and poorer psychosocial outcomes which argues against reducing numbers of antenatal visits.

Analysis of genotypic diversity and relationships among Pseudomonas stutzeri strains by PCR-based genomic fingerprinting and multilocus enzyme electrophoresis

Molecular fingerprinting procedures including random amplified polymorphic DNA-PCR (RAPD), repetitive extragenic palindromic PCR (rep-PCR) with REP, ERIC, and BOX primers and multilocus enzyme electrophoresis (MLEE) were used for genotypic characterization of 16 P. stutzeri strains originally isolated from marine, waste water, clinical and soil samples. A distinct genotype of each strain and overall great genotypic diversity were found within P. stutzeri. Cluster analysis (UPGMA) of the electrophoretic patterns of all PCR-based methods used resulted in concordant grouping of 8 strains. With the other strains conflicting clustering was noticed. The variability of clustering in PCR-based analyses suggested the occurrence of chromosomal rearrangements. When RAPD-, rep-PCR and MLEE fingerprints were used in a cluster analysis of combined electrophoretic patterns, the P. stutzeri strains could be differentiated into seven distinct genotypic groups. These results supported the subdivision of the species in several genomovars and reproduced, with higher resolution, the strain grouping after 16S rRNA phylogenetic reconstruction. The combined use of several fingerprint-based genotypic analyses results in higher resolutive strain clustering by UPGMA than each of the single ones analyzed separately. Additionally, this combination of individual typings proved to be reliable of the determination of the great genotypic diversity and relationships among the P. stutzeri strains.

Does reducing the frequency of routine antenatal visits have long term effects? Follow up of participants in a randomised controlled trial

1117 low risk women, who had been randomly allocated to either the traditional schedule of 13 antenatal visits or a reduced schedule of six to seven visits, were followed up 2.7 years after their delivery. Follow up was by means of a postal questionnaire (assessing the mother-child relationship, maternal psychological wellbeing, health service use, health-related behaviour and health beliefs), and patient record data on the frequency of contacts in general practice. There was no evidence of differences between the two groups for any of the outcomes examined. Offering a reduced schedule of routine antenatal visits to low risk women does not appear to have any long term effects.

Women's satisfaction with traditional and reduced antenatal visit schedules

OBJECTIVE

to ascertain: (i) which demographic, obstetric, maternity care, practical and attitudinal variables, and which variables relating to social support and life problems predict satisfaction with traditional antenatal visit schedules; and (ii) which of these variables predict satisfaction with reduced antenatal visit schedules.

DESIGN

a secondary analysis of data from the Antenatal Care Project (a randomised controlled trial comparing two schedules of routine antenatal visits).

SETTING

three hospitals and their community sites in south-east London.

PARTICIPANTS

1882 pregnant women, that is all those who took part in the Antenatal Care Project, on whom maternity record data were available, and who returned their antenatal questionnaire.

INTERVENTION

participants were randomly allocated to follow either the traditional schedule of 13 routine antenatal visits, or a reduced schedule of seven visits for nulliparous women and six visits for multiparous women.

MEASUREMENTS

a questionnaire developed specifically for the Antenatal Care Project. Also some data extracted from women's maternity records.

FINDINGS

women satisfied with reduced schedules were more likely to live in rented accommodation, and to have a caregiver who both listened and encourage them to ask questions than women not satisfied with reduced schedules. Women satisfied with the reduced schedules were less likely to be depressed in pregnancy than those not satisfied with reduced schedules. Women satisfied with the traditional schedule were more likely to have their general practitioner involved in their antenatal care, and to receive social support from relatives than those not satisfied with the traditional schedule. Initial preferences and expectations were also associated with satisfaction.

KEY CONCLUSIONS AND IMPLICATIONS FOR PRACTICE

(i) groups most likely to be satisfied with traditional or reduced antenatal visit schedules cannot be easily identified. It is therefore necessary to talk to women individually, and tailor care to their particular preferences; (ii) social support for depressed women needs to be safeguarded if reduced schedules are to be introduced; (iii) improving the psychosocial quality of antenatal care may be a good strategy for making reduced visit schedules more acceptable to pregnant women.

A randomised controlled trial comparing two schedules of antenatal visits: the antenatal care project

OBJECTIVE

To compare the clinical and psychological effectiveness of the traditional British antenatal visit schedule (traditional care) with a reduced schedule of visits (new style care) for low risk women, together with maternal and professional satisfaction with care.

DESIGN

Randomised controlled trial.

SETTING

Places in south east London providing antenatal care for women receiving shared care and planning to deliver in one of three hospitals or at home.

SUBJECT

2794 women at low risk fulfilling the trial's inclusion criteria between June 1993 and July 1994.

MAIN OUTCOME MEASURES

Measures of fetal and maternal morbidity, health service use, psychosocial outcomes, and maternal and professional satisfaction.

RESULTS

Pregnant women allocated to new style care had fewer day admissions (0.8 v 1.0; P=0.002) and ultrasound scans (1.6 v 1.7; P=0.003) and were less often suspected of carrying fetuses that were small for gestational age (odds ratio 0.73; 95% confidence interval 0.54 to 0.99). They also had some poorer psychosocial outcomes; for example, they were more worried about fetal wellbeing antenatally and coping with the baby postnatally, and they had more negative attitudes to their babies, both in pregnancy and postnatally. These women were also more dissatisfied with the number of visits they received (odds ratio 2.50; 2.00 to 3.11).

CONCLUSIONS

Patterns of antenatal care involving fewer routine visits for women at low risk may lead to reduced psychosocial effectiveness and dissatisfaction with frequency of visits. The number of antenatal day admissions and ultrasound scans performed may also be reduced. For the variables reported, the visit schedules studied are similar in their clinical effectiveness. Uncertainty remains as to the clinical effectiveness of reduced visit schedules for rare pregnancy problems.

A survey of health professionals' views on possible changes in the provision and organisation of antenatal care

OBJECTIVE

To ascertain the views of midwives, obstetricians and general practitioners (GPs) on possible changes in the provision of antenatal care, and to describe any differences in attitude between the three professional groups.

DESIGN

survey using postal questionnaire.

SETTING

Three hospitals in south-east London.

PARTICIPANTS

The questionnaire was sent to 251 midwives, 50 obstetricians, and 438 GPs. The overall response rate was 70%.

MEASUREMENTS

A questionnaire asking whether the health professionals would like to see, were undecided, or would not like to see, 12 possible changes in the provision of antenatal care.

FINDINGS

The changes that most health professionals wanted to see were individualised visit schedules and an increase in continuity of care-giver. There were significant differences between the three professional groups for 11 of the 12 possible changes, with midwives being the group most keen, and GPs tending to be the least keen, to see change.

KEY CONCLUSIONS

It is important to recognise and address the different views of midwives, obstetricians and general practitioners at this time when major changes in the organisation of antenatal care are being planned or implemented.

IMPLICATIONS FOR PRACTICE

Differences in attitudes between health professionals need to be addressed when planning changes in the provision of antenatal care.

The pathophysiological changes of experimental fat embolism: early pre-hypoxaemic changes

Glyceryl trioleate has been injected into greyhounds as a model of the fat embolism syndrome. Pulmonary vascular pressures, systemic arterial pressure and cardiac output were determined at regular intervals over an 8-hour period. It has been shown that glyceryl tioleate causes an increased pulmonary vascular resistance and a fall in cardiac output. These effects are mediated partly by a direct mechanical block of pulmonary vessels and partly through a thrombogenic property of the injected fat. The relevance of these findings to the clinical situation is discussed and a sequence of events for the fat embolism syndrome is proposed.

Computer-based modeling in the teaching of steady-state enzyme kinetics

Equations are derived for the steady-state treatment of enzyme reactions with one type of inhibitor, consisting of one reaction cycle or two connected cycles. Computerized stimulation programs are described which are designed to acquaint the student thoroughly with the behavior of enzyme systems. The user has freedom in the choice of parameters for the system, including up to three product-producing rate constants for the two-cycle system.