Birth size and arterial compliance in young adults

Impaired fetal growth may cause reduced compliance of the aorta and other large arteries, and predispose an individual to higher blood pressure in later life. We found that neither low birth size nor interaction between birth size and adult size were associated with arterial pulse-wave velocity in men and women aged 25 years.

The perceptions of rural nurses towards role change within the context of organisational change

This paper, derived from The role and function of the rural nurse in Australia study, describes the effects of organisational change upon the rural nurses participating in the study. It appears that whilst change is an inevitable and regular feature of rural health service delivery, it does not necessarily benefit rural nurses or communities for reasons unique to rural life. Nurses in the study responded positively to organisational change when it was congruent with the rural norms of community consultation and collaboration, or when it ensured the long-term viability of the health service. They responded negatively to organisational change that caused role overload, role conflict or role insecurity, particularly when they perceived they had little control over the change process. This paper emphasises the need for nurses to actively participate in the change processes affecting their livelihood and their communities.

Phylogenetic differentiation of two closely related Nitrosomonas spp. That inhabit different sediment environments in an oligotrophic freshwater lake

The population of ammonia-oxidizing bacteria in a temperate oligotrophic freshwater lake was analyzed by recovering 16S ribosomal DNA (rDNA) from lakewater and sediment samples taken throughout a seasonal cycle. Nitrosospira and Nitrosomonas 16S rRNA genes were amplified in a nested PCR, and the identity of the products was confirmed by oligonucleotide hybridization. Nitrosospira DNA was readily identified in all samples, and nitrosomonad DNA of the Nitrosomonas europaea-Nitrosomonas eutropha lineage was also directly detected, but during the summer months only. Phylogenetic delineation with partial (345 bp) 16S rRNA gene sequences of clones obtained from sediments confirmed the fidelity of the amplified nitrosomonad DNA and identified two sequence clusters closely related to either N. europaea or N. eutropha that were equated with the littoral and profundal sediment sites, respectively. Determination of 701-bp sequences for 16S rDNA clones representing each cluster confirmed this delineation. A PCR-restriction fragment length polymorphism (RFLP) system was developed that enabled identification of clones containing N. europaea and N. eutropha 16S rDNA sequences, including subclasses therein. It proved possible to analyze 16S rDNA amplified directly from sediment samples to determine the relative abundance of each species compared with that of the other. N. europaea and N. eutropha are very closely related, and direct evidence for their presence in lake systems is limited. The correlation of each species with a distinct spatial location in sediment is an unusual example of niche adaptation by two genotypically similar bacteria. Their occurrence and relative distribution can now be routinely monitored in relation to environmental variation by the application of PCR-RFLP analysis.

Virtual arthroscopy training: do the "virtual skills" developed match the real skills required?

The purpose of the study is to validate the training efficacy of the PC-based Sheffield Knee Arthroscopy Training System (SKATS, as described in MMVR6). Based on a task analysis of real arthroscopy, an evaluation module has been designed to test the core psycho-motor skills used in arthroscopy. The evaluation simulates a joint inspection and triangulation task, which is used to assess the research hypothesis that experienced arthroscopists will perform significantly better on the virtual arthroscopy simulator, than a trainee arthroscopist group and a control group. A group of experienced arthroscopic knee surgeons, a trainee surgeon group and a control group were tested on the simulator. The preliminary results indicate that experienced surgeons performed best with fewer instrument collisions and faster task-completion times. The results indicate that the core skills of arthroscopy used on the SKATS simulator are similar to those used in real arthroscopy. Further validation work is required to assess the training transfer effects. Once the simulator has been validated fully, it may prove beneficial in minimising patient risk.

Effects of size of health service on scope of rural nursing practice

This paper presents the findings of an analysis of the activities of rural nurses from a national audit of the role and function of the rural nurse (Hegney, Pearson and McCarthy 1997). The results suggest that the size of the health service (defined by the number of acute beds) influences the activities of rural nurses. Further, the study reports on the differences of the context of practice between different size rural health services and the impact this has on the scope of rural nursing practice. The paper will conclude that the size of the health service is an outcome of rurality (small population densities, distance from larger health facilities, lack of on-site medical and allied health staff). It also notes that the size of the health service is a major contextual determinant of patient acuity and staff skill-mix in small rural hospitals, and therefore the scope of rural nursing practice.

Epidemiology of Cryptosporidium parvum in symptomatic paediatric oncology patients

BACKGROUND

Although Cryptosporidium parvum is known to cause significant morbidity in immunocompromised individuals, including adults with cancer, the epidemiology of this pathogen in paediatric oncology patients is not known.

OBJECTIVE

We prospectively investigated the incidence of symptomatic C. parvum infection in children receiving treatment for malignancy.

METHODOLOGY

Over a 9 month period, all oncology inpatients with diarrhoea had stool analysis for C. parvum oocysts. The incidence of cryptosporidiosis was also recorded in non-oncology patients who had a stool analysed for C. parvum during the 6 years of the study period.

RESULTS

None of the 149 stool samples from 60 oncology patients analysed contained C. parvum oocysts. Thirteen per cent of 173 samples from non-oncology patients were positive for C. parvum oocysts.

CONCLUSIONS

In contrast to studies of adult oncology patients, paediatric oncology patients in our institution appear at low risk of cryptosporidiosis.

Residual blood in neonatal oxygenators after drainage

The objective of this investigation was to measure the quantity of residual blood remaining in neonatal cardiopulmonary bypass (CPB) circuits after they had been drained and to assess the overall significance with regards to total patient blood volume. The residual blood volume left in three infant/neonatal CPB circuits-Medtronic Minimax 3381 (Group MM; n = 5), Polystan Safe Micro (Group SM; n = 6), and Terumo Capiox 308 (Group CX; n = 3)--after they had been drained was determined. This was done by using an electronic scale to weigh the circuit before setup and after CPB when all possible blood was recovered from it. Total priming volume, estimated patient blood volume, residual blood volume, surgical blood loss in theater, and autogeneic blood usage were recorded in each case. Mean residual blood volumes measured were MM = 161 ml (SD 27 ml), SM = 103 ml (SD 19 ml), and CX = 133 ml (SD 15 ml). These volumes were significant, because calculations show that the volume of red cells lost in the circuit is equivalent to fourteen percent of the total patient blood volume. In view of this, neonatal oxygenator design should be minimized to reduce the priming volume and more consideration should be given to ease of residual blood recovery.

X-ray crystal structure of the Desulfovibrio vulgaris (Hildenborough) apoflavodoxin-riboflavin complex

The apoprotein of flavodoxin from Desulfovibrio vulgaris forms a complex with riboflavin. The ability to bind riboflavin distinguishes this flavodoxin from other short-chain flavodoxins which require the phosphate of FMN for flavin binding. The redox potential of the semiquinone/hydroquinone couple of the bound riboflavin is 180 mV less negative than the corresponding complex with FMN. To elucidate the binding of riboflavin, the complex has been crystallized and the crystal structure solved by molecular replacement using native flavodoxin as a search model to a resolution of 0.183 nm. Compared to the FMN complex, the hydrogen-bonding network at the isoalloxazine sub-site of the riboflavin complex is severely disrupted by movement of the loop residues Ser58-Ile64 (60-loop) which contact the isoalloxazine by over 0.35 nm, and by a small displacement of the isoalloxazine moiety. The 60-loop movement away from the flavin increases the solvent exposure of the flavin-binding site. The conformation of the site at which 5'-phosphate of FMN normally binds is similar in the two complexes, but in the riboflavin complex a sulphate or phosphate ion from the crystallization buffer occupies the space. This causes small structural perturbations in the phosphate-binding site. The flexibility of the 60-loop in D. vulgaris flavodoxin appears to be a contributing factor to the binding of riboflavin by the apoprotein, and a feature that distinguishes the protein from other 'short chain' flavodoxins. In the absence of the terminal phosphate group, free movement at the 5'-OH group of the ribityl chain can occur. Thus, the 5'-phosphate of FMN secures the cofactor at the binding site and positions it optimally. The structural changes which occur in the 60-loop in the riboflavin complex probably account for most of the positive shift that is observed in the midpoint potential of the semiquinone/hydroquinone couple of the riboflavin complex compared to that of the FMN complex.

Central venous catheter infections treated with teicoplanin

A novel way of using teicoplanin in situ to treat central venous catheters is described. Profound immunosuppression and the fact that the lines remain indwelling for long periods are two of the main reasons for these infections. In children it is also difficult to prevent these lines being played with, which increases the likelihood of infection. The different types of infection that can occur in a central venous catheter are described and the clinical definition of a catheter infection is provided. In an initial study, infective episodes in a small group of 11 children were treated successfully with in situ amikacin. Most pathogens were Gram-negative cocci. None of the catheters had to be removed, and catheter life was prolonged by a mean of 118 d. Due to the high incidence of Staphylococcus epidermidis in the initial study, in situ teicoplanin was assessed in a subsequent study. Over the course of 1 yr, 20 line infections occurred in 12 children. Empirical amikacin therapy was instituted and switched to teicoplanin once the pathogen was confirmed as Gram-positive. An antibiotic-heparin mixture was introduced into the line and left in place for 24 h, after which time it was replaced with fresh mixture until cultures were sterile. All pathogens were sensitive to teicoplanin, all infections were treated successfully and no catheters had to be removed. Overall, catheter life was prolonged by a mean of 136 d. It was concluded that in situ teicoplanin was effective and well tolerated for line infections (no side-effects were reported during the study). A minimum of 6 d therapy was recommended. The patients with less severe infections would have been suitable for treatment at home by their parents, district nurse or general practitioner (GP).

Evidence-based practice and rural nursing: a literature review

This literature review is an exploration of issues related to evidence-based practice and rural nursing. Given the contribution that nursing research can make to improved client care in rural areas, it is important that nurses' awareness and understanding of evidence-based practice be enhanced, and that strategies for fostering the development of clinically relevant programs of nursing research be identified for rural health services. The review highlights the deficiencies in the current metropolitan-based approaches to evidence-based practice that may disadvantage rural clients and nursing practitioners, because they do not accommodate the inherent differences in rural and metropolitan healthcare cultures. It emphasises the need to seek approaches to research-based practice that arise from the specific needs of the rural setting.

Effects of pulsed ultrasound on embryonic development: an in vitro study

Whole-embryo culture was used as the model system to study the effects of pulsed ultrasound on embryonic development. Rat embryos (9.5 days old) were exposed to a wide range of ultrasound levels at ultrasound frequencies between 1-4 MHz for 30 min in vitro. After 48 h in culture, absolute control, sham and treatment embryos were assessed for viability, morphology, growth and development. At an ambient temperature of 37 degrees C, no significant effects were observed for spatial peak temporal average intensities below 4 W/cm2 or peak negative pressures below 1.9 MPa. At higher acoustic levels, there was a significant increase in the number of nonviable embryos and the number of morphological abnormalities in viable embryos increased. Abnormal cephalocaudal flexion and abnormal head development were the most common gross morphological abnormalities. Both thermal and nonthermal bioeffect mechanisms are involved.

Necrotizing fasciitis of the retroperitoneum: an unusual presentation of group A Streptococcus infection

A 14-year-old girl presented with symptoms resembling acute appendicitis. Five days after appendectomy and continued fever and severe abdominal pain, blood cultures were found positive for Streptococcus pyogenes. Two days later a diagnosis of group A streptococcal peritonitis with necrotizing retroperitoneal fasciitis was confirmed by retroperitoneal cultures obtained at laparotomy. Although multiple organ systems showed impaired functioning, including hepatic, renal and respiratory changes, she did not meet the criteria for streptococcal toxic shock syndrome. She was treated with a combination of high-dose parenteral penicillin and clindamycin, followed by prolonged treatment with clindamycin orally. Recovery was complicated by persistent hydronephrosis, which was slow to resolve.

Specification of left-right asymmetry in mammals: embryo culture studies of stage of determination and relationships with morphogenesis and growth

The internal mammalian body plan is laterally asymmetric with a consistent handedness such that some organs are placed on one side (stomach on the left, for example) and paired organs are not symmetric (for example, there are more lung lobes on the right). Some chemical teratogens can affect the development of asymmetry, and some can cause asymmetric defects in overtly symmetric structures, but the mechanisms are unknown. We have used chemical treatment of rat embryos in culture to examine the stage at which the left-right axis is determined and show that all effective treatments can affect left-right axis development up to the early headfold stage, but not from late headfold onwards. This suggests that the left-right axis is determined by the late headfold stage, even though the embryo is overtly symmetric at this stage. It appears to be much easier to induce an abnormal left-right axis from late allantoic bud and early headfold stages than the early allantoic bud stage, but we have not established the earliest stage at which a response can be induced. Complete situs inversus was the most common chemically induced abnormality, although heart looping and body turning could be inverted separately, suggesting that the two phenomena are linked but not wholly interdependent. The treatments appeared to cause a loss of handedness, rather than inducing inversion, since the incidence of an abnormal left-right axis never exceeded 50%. All treatments except methoxamine, an alpha1 adrenergic agonist, induced an abnormal left-right axis in association with other morphologic defects and growth retardation. However, there was no relationship between the severity or incidence of dysmorphology, nor growth retardation, and left-right abnormality, suggesting that although the process that specifies lateral asymmetry is labile, it is independent of general growth and morphogenesis.

A prospective study of Clostridium difficile infection and colonization in pediatric oncology patients

BACKGROUND

Patients with cancer often receive broad spectrum antibiotics in addition to antineoplastic chemotherapy. Both treatments predispose adult oncology patients to infection and colonization with Clostridium difficile, but the role of this pathogen in pediatric oncology patients is poorly defined.

METHODS

A prospective study of 149 fecal samples from symptomatic pediatric oncology patients and 58 samples from asymptomatic patients was performed. Each sample was analyzed for the presence of C. difficile and its toxins A and B.

RESULTS

In 8.7% of the symptomatic samples and 19% of the asymptomatic samples toxigenic C. difficile was found. No association was found between either the use of antibiotics and/or the administration of chemotherapy and the presence of toxigenic C. difficile. Younger children were more likely to be infected or colonized with C. difficile, and there was no evidence of nosocomial transmission of C. difficile within the study population.

CONCLUSIONS

As toxigenic C. difficile may form part of the normal flora in young children, this study indicates that in the absence of a defined outbreak, C. difficile does not appear to be an important pathogen in pediatric oncology patients.

Survey of obstetricians' personal preference and discretionary practice

OBJECTIVE

To determine obstetricians personal choices in relation to Down syndrome screening and mode of delivery for themselves or their partners.

STUDY DESIGN

Structured anonymous postal survey. All 282 obstetric consultants, senior registrars and registrars in NHS obstetric units within London's M25 region were surveyed.

RESULTS

The response rate was 73% (206). Fifty one per cent (105) chose to have elective amniocentesis/CVS without a previous screening test when maternal age was > or = 35 years and 11% (23) when < 35 years. Of the remainder, the majority wanted both maternal serum screening and nuchal translucency rather than a single screening test. In relation to mode of delivery, 17% (33) of obstetricians chose elective caesarean section (CS) in the absence of any clinical indication. Of those who chose CS, 88% did so out of fear of perineal damage. However when faced with a mid-cavity instrumental delivery in the second stage, only 5% (8) wanted CS, the remainder choosing operative vaginal delivery. With an uncomplicated breech presentation, only 27% (55) opted for external cephalic version while 57% (114) chose elective CS.

CONCLUSION

This study demonstrates interventionist attitudes among a sizeable percentage of obstetricians in relation to antenatal screening and their own preferred mode of delivery. It suggests that obstetricians regard management options not normally available to pregnant women as valid choices for themselves or their partners.

Medical amnioreduction with sulindac to reduce cord complications in monoamniotic twins

OBJECTIVE

Cord entanglement is a common complication of monoamniotic twins and it is associated with high perinatal mortality. Apart from preterm delivery, no treatment has previously been used to reduce the risks of this complication. We postulated that reducing amniotic fluid volume would stabilize fetal lie and reduce the risk of cord compression.

STUDY DESIGN

Cord entanglement was documented in three cases of monoamniotic twins in the midtrimester. Sulindac was administered to the mother. Amniotic fluid index, fetal urine output, and umbilical artery and ductus arteriosus Doppler waveforms were investigated before and during treatment by use of real-time and pulsed Doppler techniques.

RESULTS

Sulindac was associated with a dose-related reduction in amniotic fluid index and fetal urine production without alteration in fetal flow velocity waveforms. Fetal lie stabilized after commencement of treatment. All six twins were delivered with no complications.

CONCLUSION

Medical amnioreduction with sulindac is a new management option in monoamniotic twins to reduce cord complications.

Protecting the public health--the role of environmental health

This article seeks to review the key concepts and issues central to environmental health in relation to the protection of public health. It will focus on the holistic framework in which environmental health operates and the major threats faced. The key issue to be addressed is the need for collaboration at the professional and organisational level as a central prerequisite for a healthy nation.

Nitric oxide synthase in human placenta and umbilical cord from normal, intrauterine growth-retarded and pre-eclamptic pregnancies

1. It has been suggested that a deficiency of nitric oxide (NO) may explain many of the pathophysiological features of pre-eclampsia (PE) and intra-uterine (foetal) growth retardation (IUGR). To elucidate further the role of NO in the pathophysiology of pregnancy we have determined the relative amount and activity of NO synthase (NOS) in first trimester and normal-term placental tissues, as well as in the placenta and umbilical cord in pregnancies complicated by PE and IUGR, using NG-nitro-L-[2,3,4,5(-3)H]-arginine ([3H]-L-NOARG) binding, quantitative in vitro autoradiography, [3H]-arginine to [3H]-citrulline conversion and Western blotting. 2. Specific, high affinity (KD = 38 nM) [3H]-L-NOARG binding was demonstrated in the villous trophoblast of normal-term placentae. Binding was calcium-independent, stereoselective and exhibited a rank order of inhibition by NOS inhibitors and substrate (L-NOARG > or = L-NMMA > or = 7-NI > L-NAME > L-Arg > or = L-NIO > ADMA). 3. [3H]-L-NOARG binding density and NOS activity were both significantly greater in placental tissues from first trimester and PE or IUGR complicated pregnancies compared to normal-term placentae. 4. Western blotting, using an endothelial NOS peptide antiserum, demonstrated a approximately 140 KDa protein band in placental extracts and indicated that the amount of immunoreactive material was significantly greater in first trimester compared to normal-term placentae. 5. Specific [3H]-L-NOARG binding was also localized to the endothelial lining of umbilical arteries and veins, binding density being greater in the artery than the vein. [3H]-L-NOARG binding to the umbilical artery endothelium was significantly lower in PE and IUGR complicated pregnancies compared to normal-term controls. 6. The role of trophoblast-derived NO in human placental pathophysiology remains to be established, but differences in the amount of placental [3H]-L-NOARG binding, NOS activity and immunoreactive material indicate that expression of NOS in the villous trophoblast falls during pregnancy. Conversely, the apparent reduction in NOS in the umbilical artery endothelium in PE and IUGR complicated pregnancies may be indicative of endothelial dysfunction.

Endothelial cell "swelling" in ischaemia and reperfusion

The endothelial cells of cardiac capillaries have been reported to swell as a result of ischaemia and reperfusion although there has not previously been any attempt to quantify this observation. Whole capillary and luminal cross-sectional areas, abluminal and luminal membrane lengths were measured from electron micrographs of isolated rat hearts subjected to 30 or 60 min of global ischaemia both with and without subsequent reperfusion for 15 min. All the experimental protocols resulted in capillaries which appeared swollen by electron microscopy. Measurements, however, showed that, after 30 and 60 min ischaemia, this appearance was brought about by a decrease in both whole capillary and luminal area causing an increase in the distance between abluminal and luminal membranes without any change in the endothelial cell cross-sectional area. Reperfusion after 30 min caused an increase in capillary dimensions to larger than control levels. Only after 60 min ischaemia with reperfusion were the cells really swollen with an increase in cross-sectional area. We conclude that (1) we may be observing capillary constriction and (2) the word "swelling" in this context should be used with caution.

"In-situ" Teicoplanin for central venous catheter infection

Infection of central venous catheters (CVC) is a relatively common occurrence in immunocompromised patients, management of which has included I.V. antibiotics +/- removal of catheter. We have previously demonstrated that intracatheter administration of Amikacin empirically, successfully eradicated all bacterial infections except those due to S. epidermidis. A study was subsequently undertaken to treat gram positive cocci infections of CVC with intracatheter Teicoplanin. Eleven patients attending a single institution with documented gram positive cocci infection of CVC over a one year period were included in the study. Teicoplanin was instilled with heparinised saline once daily into the infected lumen of the CVC and allowed to remain for 24 hours. Treatment was continued for 48 hours after negative cultures were reported. Teicoplanin was successful in eradicating infection in 100% of cases. Mean duration of treatment was six days (range 4-9 days). Four patients subsequently developed a further infection, a mean of 13 weeks from first infection, only one of which was due to the same organism and this was successfully treated by a further course of Teicoplanin. No side effects were reported and catheter life was prolonged a mean of 132 days after completion of treatment. The use of Teicoplanin in this way for treatment of gram positive cocci infection of CVC is highly effective; once daily administration of antibiotic enables treatment to be given on an outpatient basis, thereby minimising hospital admission.