Angiotensin II modulates cardiovascular autonomic control in the absence of baroreflex loading

OBJECTIVE

To investigate the effects of angiotensin II in the absence of baroreflex activation.

DESIGN

Ten healthy male volunteers were studied in a single blind, randomised, crossover study of heart rate variability during intravenous angiotensin II infusion (5-20 ng/kg/min) compared with a control pressor infusion of phenylephrine (0.7-2.8 micrograms/kg/min). Each infusion was titrated to increase mean blood pressure by 20 mm Hg; sodium nitroprusside was then infused simultaneously to restore blood pressure to baseline values.

RESULTS

During concomitant angiotensin II (AII) and sodium nitroprusside (SNP) infusion, the mean (SD) RR interval (864 (117) ms) was significantly shorter than during phenylephrine (PE) and sodium nitroprusside infusion (1057 (163) ms), and was significantly shorter than at baseline (999 (164) ms), despite comparable levels of blood pressure. Values of high frequency heart rate variability measured in the time and frequency domains were significantly lower during AII/SNP infusion than during PE/SNP: percentage of successive RR interval differences exceeding 50 ms, 30(16)% v 57(21)%; root mean square of successive RR interval differences, 63 (39) v 90 (40) ms; high frequency power 0.48 (0.19) v 0.66 (0.26) nu.

CONCLUSIONS

When the pressor response is controlled by sodium nitroprusside, angiotensin II infusion is associated with tachycardia. Analysis of heart rate variability suggests that this reflects inhibition of cardiac vagal activity.

Breast awareness project for women with a learning disability

In 1995/6, while conducting a quality assurance evaluation in a residential group home for adults with a learning disability, the subject of breast screening and the importance of early detection of breast abnormalities was raised by a member of staff. At the time, the Mulberry Trust had a quality standard that women between 50 and 64 years who are supported in continuing care should attend breast screening clinics on a 3-yearly basis if they wish. A pilot scheme was devised based on the premise that breast awareness for service users should be promoted. It was decided that the scheme should include a breast examination, conducted on a monthly basis, ideally by the service users themselves, or by suitably trained staff on their behalf. The pilot scheme was implemented using available research and training was provided for qualified nursing staff within the trust. The training covered breast cancer prevention and breast awareness. After 7 months the scheme was evaluated and changes were made to policy and practice, including consultation with the trust's ethics panel regarding implementation of procedures. Training for staff in breast awareness continues and the scheme is slowly being introduced across the trust to enable all service users to be involved, both in residential homes and community settings. However, in future, the emphasis will be on identifying changes in the breast during normal care routines, such as bathing and dressing, as opposed to formal, clinical examination.

From the Journals

NURSES' KNOWLEDGE AND PRESSURE SORE TREATMENT POPLITEAL VEIN REFLUX.

Five-year follow-up of a prospective randomised multi-centre trial of weekly chemotherapy (CAPOMEt) versus cyclical chemotherapy (CHOP-Mtx) in the treatment of aggressive non-Hodgkin's lymphoma. Central Lymphoma Group

BACKGROUND

Weekly alternating regimen known as CAPOMEt is compared to standard cyclical chemotherapy (CHOP-Mtx) in aggressive non-Hodgkin's lymphoma (NHL).

PATIENTS AND METHODS

Three hundred and eighty-one patients with aggressive NHL were randomised to receive either cyclophosphamide, doxorubicin, vincristine, prednisone and methotrexate (CHOP-Mtx) on a cyclical basis or a weekly regimen incorporating the same drugs with the addition of etoposide (CAPOMEt).

RESULTS

After pathological review, 281 patients were deemed eligible. At the census date of 31 March 1994, 158 patients were alive with a median follow up of 5.9 years (minimum 3.0 years). Analysis of all patients and eligible patients showed no significant treatment differences in the rates of complete remission (CR), failure free survival (FFS) or overall survival (OS) between the two arms. The actuarial median OS was 24 months for CAPOMEt compared with 31 months for CHOP-Mtx, with five-year actuarial survival rates of 37% and 43%, respectively. Myelosuppression was significantly more severe with CHOP-Mtx and neurotoxicity was much more common with CAPOMEt.

CONCLUSION

Weekly CAPOMEt is equally effective as standard cyclical CHOP-Mtx treatment in aggressive NHL.

Planning and implementing an anesthesia crisis resource management course for student nurse anesthetists

Development of Anesthesia Crisis Resource Management (ACRM) skills is a highly desirable outcome of a nurse anesthesia educational program. Access to an ACRM course is limited by a variety of factors including cost, availability of a center, time constraints, and the lack of adequately prepared CRNA faculty. The authors describe a Nurse Anesthesia Program's planning and implementation of an ACRM course by using a high fidelity human simulator. Key supportive and logistical elements necessary to implement an ACRM course are described. The authors address administrative concerns, faculty preparation needs, and explain the process of course design. Strengths of the course and problems encountered during the implementation of the experience are described. Feedback from participating students, faculty perceptions, and lessons learned from the experience are shared.

Sleep states and neonatal pulse oximetry

AIM

Pulse oximetry is a quick, easy, noninvasive method widely used for monitoring oxygen saturation (SaO2) in the neonatal period. The greatest recognized problem with SaO2 readings measured from the oximeter is artifact, arising from an inability to record accurately during movement. The aim of this study was to determine the proportion of pulse oximeter readings affected by movement artifact during sleep in term and preterm infants.

METHOD

Polygraphic recordings were obtained from 11 term and 6 preterm infants at postconceptional ages (SD) of 39.8 (0.8) and 39.3 (1.5) weeks respectively. The polygraphic and computer recordings were divided into epochs of 30 seconds duration and identified as active sleep (AS), quiet sleep (QS), indeterminate sleep (IS), or wakefulness (AW), using electrophysiological parameters and behavioral observations. Movement artifact was identified by visual examination of polygraphic computer recordings using strict criteria. Signal containing artifact was removed from recordings and the percentage of artifact time present per recording calculated.

RESULTS

Signal artifact was present in recordings of all infants studied, comprising an average state time of 19% during quiet sleep, 49% of active sleep, 49% of indeterminate sleep and 91% of wakefulness. A significant difference in the proportion of artifact present in recordings of term and preterm was observed only during quiet sleep.

CONCLUSION

Movement artifact during pulse oximetry recordings is dependent on behavioral state, and overall affects up to 50% of recorded traces. A reliable and more accurate noninvasive method of recording oxygen saturation is thus needed, for use in both neonatal nurseries and in sleep studies, to aid in accurate clinical decision-making.

Association of a Phloem-Limited Bacterium with Yellow Vine Disease in Cucurbits

Since 1991, a new disease of cucurbits in central Texas and Oklahoma, designated yellow vine, has resulted in the decline and plant death of watermelon, cantaloupe, squash, and pumpkin. Affected plants are characterized by leaf yellowing, phloem discoloration, and plant collapse. Year-to-year variation in disease incidence has ranged from spotty outbreaks to complete crop loss in early-planted watermelon fields. A systematic investigation to determine the causal agent of the disease included pathogen isolation attempts, transmission tests, serological assays with various antisera (enzyme-linked immunosorbent assay and Western blotting), and DNA hybridizations with selected probes (dot and Southern blots). None of these tests revealed a consistent relationship between the expression of yellow vine symptoms and the presence of a particular microorganism or virus in the plant. However, transmission electron microscopic examination showed the consistent presence of a bacterium in the phloem sieve elements of symptomatic plants. The rod-shaped bacteria, observed only in symptomatic cucurbits, measured 0.25 to 0.5 μm in width and 1.0 to 3.0 μm in length and were surrounded by a triple-layered cell envelope.

Polymerase chain reaction detection and phylogenetic characterization of an agent associated with yellow vine disease of cucurbits

ABSTRACT Diagnosis of yellow vine disease (YVD) in cucurbits, an important disease in the south-central United States, relies on external symptom appearance, phloem discoloration, and the presence of bacterium-like organisms (BLOs) in phloem. Polymerase chain reaction (PCR) amplification of BLO nucleotide sequences was explored as a means to improve diagnostic techniques. PCR, using a primer pair based on sequences of the citrus-greening BLO, amplified a 0.15-kilobase (kb) fragment from the DNA of symptomatic plants, but not from that of asymptomatic plants. Its nucleotide sequence suggested that the DNA amplified was of pro-karyotic origin. A primer pair, designed to amplify nonspecific prokaryotic 16S rDNA, amplified a 1.5-kb DNA fragment in both the symptomatic and asymptomatic plants. The 1.5-kb fragment from the asymptomatic plants corresponded to chloroplast 16S rDNA, and the band from the symptomatic plants was composed of 16S rDNAs from both chloroplasts and a prokaryote. The nucleotide sequence of the prokaryotic DNA was determined and used to design three primers (YV1, YV2, and YV3). Fragments of 0.64 and 1.43 kb were amplified with primers YV1-YV2 and primers YV1-YV3, respectively, from symptomatic plants. Neither primer set yielded fragments from asymptomatic plants, unrelated bacteria, or selected soilborne fungal pathogens of cucurbits. Phylogenetic analysis indicated that the prokaryote is a gamma-3 proteobacterium. The consistent association of the 0.64- and 1.43-kb fragments with symptomatic plants suggests that the gamma-3 proteobacterium may be the causal agent of YVD of cantaloupe, squash, and watermelon.

Cytokine degradation by biofilms of Porphyromonas gingivalis

The aim of this study was to determine whether biofilms of Porphyromonas gingivalis could proteolytically degrade the cytokines interleukin (IL)-1beta, IL-6, or IL-1 receptor antagonist (IL-1ra). Biofilms were grown on membrane filters on the surface of Wilkins-Chalgren blood agar. The biofilms were removed from the plates, and solutions containing 2.5 microg/ml of each cytokine were added. Following incubation for up to 4.0 h, supernatants from the biofilms were subjected to SDS-PAGE. The separated proteins were transferred by Western blotting to PVDF membranes and probed with peroxidase-conjugated antibodies recognizing both the intact cytokines and their degradation products. After 2 h, no intact IL-1beta, IL-6, or IL-1ra were detectable. Cytokine proteolysis also occurred in the presence of horse serum. These results demonstrate that biofilm-grown P. gingivalis can degrade both pro- and anti-inflammatory cytokines and so may be able to perturb cytokine networks in vivo by eliminating cytokines from the local environment.

Systematic review of the school entry medical examination

AIMS

To summarise and critically evaluate research conducted in the UK between 1962 and 1996, on the effectiveness and efficiency of the school entry medical (SEM) examination.

METHODS

An electronic search of a large number of databases, in conjunction with a search of reference lists, and sources in the grey literature produced a total of 64 studies.

RESULTS

Only one overview and 16 primary studies met the review's broad inclusion criteria. The results showed significant differences in the identification and referral of new and ongoing problems not only between the routine and selective SEM but also within the two types of SEM examination. There were also large differences in the numbers of children selected for SEM examination. No study included in the review defined either the methods or the criteria used to identify children as screen positive. No study provided follow up of children after referral to estimate the positive predictive value or yield of the screening, or follow up of the whole cohort to identify false negative cases.

CONCLUSION

Data on the effectiveness and efficiency of both the routine and selective SEM examination in accurately identifying children with new or ongoing health problems are not available at the present time. The studies reviewed here demonstrate the fragility of the evidence on which the school entry medical is based, and call into question the ethical basis of this programme.

Impaired bacterial killing and hydrogen peroxide production by polymorphonuclear neutrophils in end-stage renal failure

Polymorphonuclear leukocytes (PMN) isolated from a sub-population of patients with end-stage renal failure (ESRF) who were identified because they demonstrated impaired intracellular bacterial killing, were assayed for hydrogen peroxide activity using two different techniques capable of distinguishing between total and intracellular hydrogen peroxide generation. In an attempt to elucidate the mechanism of impaired intracellular bacterial killing further, hydrogen peroxide activity was compared to PMN isolated from patients receiving continuous ambulatory peritoneal dialysis and a control group of healthy normal volunteers. PMN from conservatively treated ESRF patients demonstrated reduced production of intracellular hydrogen peroxide (mean 37.7 +/- 4.3 fluorescence units), compared to PMN from both ESRF patients treated with continuous ambulatory peritoneal dialysis (mean 57.9 +/- 6.6 fluorescence units) and normal controls (mean 60.4 +/- 3.5 fluorescence units). This suggests that the probable mechanism of impaired bacterial intracellular killing by the PMN of conservatively treated ESRF patients involves the production of intracellular hydrogen peroxide.

Pharmacomanipulation of HSV-1 induced chorioretinitis in mice

In the von Szily mouse model, intracameral inoculation of herpes simplex virus type-1 (HSV-1) results in inflammation of the ipsilateral anterior segment with relative chorioretinal sparing and destructive contralateral chorioretinitis. We studied the effect of the systemic antiviral agent acyclovir (ACV) and anti-HSV-1 antibody therapy in this model. Contralateral chorioretinitis developed in none of the 18 mice receiving ACV from post-inoculation day (pid) 1 (p < 0.0001), in 6 of 10 (60%) mice when treatment was delayed until pid 7 (p = 0.40) and in 14 of 18 (77%) controls. Contralateral disease developed in 8 of 16 (50%) mice that received anti-HSV-1 antibody from pid 1 (p = 0.02), in 13 of 16 (81%) treated from pid 5 (p = 0.64), in 7 of 8 (87.5%) treated from pid 7 (p = 1.0) and in 17 of 20 (85%) controls. We conclude that early treatment with ACV or anti-HSV-1 antibody reduces the incidence of contralateral chorioretinitis in mice.

Use of the WWW for distributed knowledge engineering for an EMR: the KnowledgeBank concept

Developing automated tools for clinical information management requires an appreciation of user needs and capabilities. To address the reality of practice style variation, and the varying degree of comfort with computers in clinical users, we developed the KnowledgeBank concept. The KnowledgeBank concept includes an end-user authoring tool for clinical content in the EMR, and a web-based repository of content for sharing clinical content. We describe the early experiences of end-users using the KnowledgeBank.

Cleft lip with or without cleft palate: effect of family history on reproductive planning, surgical timing, and parental stress

OBJECTIVE

This study tested whether the presence of a family history of nonsyndromic cleft lip with or without cleft palate (NSCLP) lessens the negative impact on reproductive planning, decreases treatment anxiety, and relieves parental stress when there is a recurrent cleft.

DESIGN

Sixty-one participating families, retrospectively ascertained through their children with NSCLP, were divided into two groups: those with a family history of clefting and those in which only the proband was affected.

SETTING

Each family completed a questionnaire either at their home or during a clinic visit.

PARTICIPANTS

Questionnaires were distributed to 117 families with an NSCLP child. Of these 117, 49 (42%) had another family member with NSCLP and 68 (58%) had no prior history of clefting. Sixty-one (52%) families returned the questionnaire and were categorized by family history.

MAIN OUTCOME MEASURES

The Parenting Stress Index and the Hollingshead Index of Social Position were included with family and medical history questions in the 137-item questionnaire.

RESULTS

The reproductive plans of the two groups were quite similar and were not dependent on the families' actual or perceived recurrence risks of NSCLP. The majority (85%) of the children with NSCLP underwent surgical closure at the recommended age. The two groups did not significantly differ on any score on the Parenting Stress Index, indicating a similar parental stress level between the groups.

CONCLUSIONS

These findings suggest that family history does not significantly influence reproductive plans, timing of cleft repair, or stress of parents of a child with NSCLP. Further, these results indicate a need for additional psychosocial study of this population.

Gene expression in the pulp of ripening bananas. Two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis of in vitro translation products and cDNA cloning of 25 different ripening-related mRNAs

mRNA was extracted from the pulp and peel of preclimacteric (d 0) bananas (Musa AAA group, cv Grand Nain) and those exposed to ethylene gas for 24 h and stored in air alone for a further 1 (d 2) and 4 d (d 5). Two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis of in vitro translation products from the pulp and peel of these fruits revealed significant up-regulation of numerous transcripts during ripening. The majority of the changes were initiated by d 2, with the level of these messages increasing during the remainder of the ripening period. Pulp tissue from d 2 was used for the construction of a cDNA library. This library was differentially screened for ripening-related clones using cDNA from d-0 and d-2 pulp by a novel microtiter plate method. In the primary screen 250 up- and down-regulated clones were isolated. Of these, 59 differentially expressed clones were obtained from the secondary screen. All of these cDNAs were partially sequenced and grouped into families after database searches. Twenty-five nonredundant groups of pulp clones were identified. These encoded enzymes were involved in ethylene biosynthesis, respiration, starch metabolism, cell wall degradation, and several other key metabolic events. We describe the analysis of these clones and their possible involvement in ripening.

Hodgkin's disease in patients older than 70 years of age: a registry-based analysis

Between 1973 and 1993, 529 patients aged 15 years and over with Hodgkin's disease (HD) were entered into a lymphoma registry. Twenty-eight cases (1 only diagnosed at autopsy) of histologically proven HD in patients aged 70 years or older were identified. The distribution of sex, 'B' symptoms, histology and stage was not significantly different from that of younger patients, except for the fact that there were no patients aged 70 years or older with lymphocyte predominant HD. Nineteen patients were treated radically, 5 patients palliatively and 4 patients received no radiotherapy or chemotherapy. Three of the 14 patients treated with chemotherapy achieved the planned dose intensity. The cause-specific 5-year survival was 75% for patients aged 15-69 years and 28% for patients aged 70 years and over (logrank chi(2) = 43.7, P < 0.00001). The younger and older groups treated with radical intent had complete response rates of 97% and 74%, respectively (logrank chi(2) = 17.91, P < 0.00001) and relapse rates at 5 years of 27% and 56%, respectively (logrank chi(2) = 4.86, P = 0.0275). The main reason for the poorer prognosis of patients aged 70 years and over was the increasing difficulty of chemotherapy delivery associated with advancing age.

Phospholipases and the activation and priming of neutrophils by peritoneal dialysis effluent

OBJECTIVE

To investigate the role of phospholipase during the activation and priming of neutrophil nicotinamide adenine dinucleotide phosphate (NADPH) oxidase by peritoneal dialysis effluent (PDE).

DESIGN

Examine the action of 4-hour dwell PDE upon phospholipase activation in the circulating neutrophils obtained from healthy individuals.

RESULTS

We have previously reported that PDE stimulated superoxide release by the NADPH oxidase of human neutrophils and primed the response to the bacterial peptide, fMLP (fMetLeuPhe). To elucidate the biochemical mechanisms underlying these observations, we have examined the roles of phospholipases (PL) C, D, and A2, whose activation causes the release of a range of intracellular secondary messengers. Following fMLP stimulation, we observed a rapid activation of both PLC and PLD as well as a small but nonsignificant increase in PLA2 activity. Peritoneal dialysis effluent alone failed to stimulate either PLC or PLD, while pre-incubation with PDE had no affect upon fMLP-induced PLC and PLD activation. However, PDE caused a small but nonsignificant increase in PLA2 activity (which was comparable to that observed with fMLP) and primed the fMLP-induced response. In common with a role for PLA2 and the subsequent release of arachidonic acid (AA), we have demonstrated dose-dependent inhibition of PDE-induced superoxide release by the PLA2 inhibitor mepacrine, as well as activation and priming of the fMLP-induced superoxide generation by AA.

CONCLUSIONS

These results imply that PDE-induced NADPH-oxidase activation and priming in human neutrophils is mediated via a PLA2-dependent but PLC- and PLD-independent mechanism.

Wound cleansing

It is not necessary or cost-effective to cleanse wounds every time a dressing is changed. This Update describes the rationale behind wound cleansing and the optimum techniques to encourage healing.

Late adolescents' perceptions of their caregiver's feeding styles and practices and those they will use with their own children

The purpose of this study was to examine the perceptions of late adolescents regarding their caregivers' feeding styles and practices and their perceptions of those they plan to use with their children. The 546 subjects were from a randomly selected sample of 1,000, nonparenting, 18 to 23-year old college students who responded to a questionnaire. Two distinct feeding styles emerged: adult-controlled and cooperative. The adult-controlled style reflects a perception of control which the adult decides what and how much a child will eat. The cooperative style reflects shared control where the adult decides what food will be presented and the child decides how much and whether to eat. Chi-square analysis of the relationship between subjects' perceptions of their caregivers' feeding styles and their perceptions of the styles they believe they will use with their children, resulted in a positive association. To examine perceived past and future feeding practices, a Pearson's r was computed on subscales from a factor analysis. Results indicated positive correlations between subjects' perceived past and future feeding practices. These results suggest generational transmission of feeding styles and practices. A recommendation is made for parent and nutrition educators to focus on both parenting styles and feeding practices.

Wound care: the healing process

When caring for a patient with a wound, regardless of its aetiology, a thorough assessment of the patient, the wound and any other relevant factors must be undertaken before care can be planned, if a successful outcome is to be achieved and realistic time scales set. Accurate wound assessment and appropriate care planning is dependant upon an understanding of the physiology of healing and any factors that may potentially delay or prolong the healing process. To be accurate and meaningful the information recorded should be concise, objective and comprehensive.