Pathological features of witnessed out-of-hospital cardiac arrest presenting with ventricular fibrillation

OBJECTIVES

To determine which characteristic pathological features are predictive of the presenting rhythm and survival in victims of community cardiac arrest.

DESIGN

Case-controlled retrospective autopsy study.

SETTING

County of Nottinghamshire with a total population of 993 914 and an area of 2183 square kilometers.

SUBJECTS

Between January 1, 1991 and December 31, 1994, 1535 witnessed cardiac arrests attended by the Nottinghamshire Ambulance Service, of which 1083 had an autopsy performed.

RESULTS

Ischaemic heart disease accounted for 72.3% of cases with a further 3.6% of deaths from other cardiac causes and the remainder from non-cardiac causes. Old healed myocardial infarction was present in 39.4%, and visible fresh occlusive thrombus was found in 23.8% of cases overall. Logistic regression analysis of deaths from cardiac causes revealed that younger age (odds ratio of 0.98 (95% CI 0.97-0.99)), two vessel coronary artery disease (odds ratio of 1.65 (95% CI 1.08-2.52)) and heart weight greater than 500 grams (odds ratio of 1.56 (95% CI 1.12-2.17)) were found to be independent predictors of developing ventricular fibrillation compared to other rhythms of arrest. Being male, visible occlusive thrombus and having survived a previous myocardial infarction were found not to be independent variables. There were no outstanding pathological features in the 31 patients who survived to hospital admission and subsequently died, compared with non-survivors who were considered to have died from a cardiac cause.

CONCLUSIONS

Among those who had a witnessed out-of-hospital cardiac arrest from a cardiac cause, increasing heart weight (the most likely cause of which is left ventricular hypertrophy), younger age and two vessel coronary artery disease appear to be much more important pathological features in the development of ventricular fibrillation than a previous myocardial infarction and fresh visible occlusive thrombus.

Evaluating pressure-reducing foam mattresses and electric bed frames

It could be argued that pressure ulcer prevention is simply a matter of matching those patients at risk of developing tissue damage with suitable pressure-reducing equipment. However, as many authors have identified, this can be complicated because of the lack of reliable evidence to support many products. This article seeks to evaluate the combination of a pressure-reducing mattress with an electric profiling bed frame. The study was conducted in a high-dependency cardiac surgery unit. Forty-four subjects were recruited during a 6-month period and their progress observed. Two outcome measures were used: pressure ulcer incidence and perceptions of comfort. No pressure ulcers developed during the trial and the perceptions of comfort were generally positive. The small sample size restricts the conclusions that can be drawn from the study, but when taken in conjunction with other small studies in this area there appear to be benefits from using such a combination of equipment.

Nonequivalent nuclear location of immunoglobulin alleles in B lymphocytes

Individual B lymphocytes normally express immunoglobulin (Ig) proteins derived from single Ig heavy chain (H) and light chain (L) alleles. Allelic exclusion ensures monoallelic expression of Ig genes by each B cell to maintain single receptor specificity. Here we provide evidence that at later stages of B cell development, additional mechanisms may contribute to prioritizing expression of single IgH and IgL alleles. Fluorescent in situ hybridization analysis of primary splenic B cells isolated from normal and genetically manipulated mice showed that endogenous IgH, kappa and lambda alleles localized to different subnuclear environments after activation and had differential expression patterns. However, this differential recruitment and expression of Ig alleles was not typically seen among transformed B cell lines. These data raise the possibility that epigenetic factors help maintain the monoallelic expression of Ig.

A comparison of individual and family psychology of adolescents with chronic fatigue syndrome, rheumatoid arthritis, and mood disorders

Chronic fatigue syndrome (CFS) is a controversial diagnosis with unknown cause. Adult studies indicate high rates of psychosocial dysfunction and psychiatric comorbidity. The authors compared three groups of pediatric patients selected by diagnosis-(1l) CFS (n = 15), (2) juvenile rheumatoid arthritis (n = 15), and (3) mood disorders (n = 15)-across many psychological measures. CFS subjects had dramatic elevation of the Somatic Complaints subscale (mean T score = 75), whereas the mood disorders group had higher externalizing scores (mean T score = 68) on the Child Behavior Checklist. The CFS subjects missed significantly more school compared with the two control groups. After the onset of CFS, 13 of 15 of the CFS patients required significant educational accommodation. Only 4 of the 15 CFS patients had an Axis I psychiatric diagnosis, as determined by the Computerized Diagnostic Interview for Children. Despite a low rate of psychiatric diagnosis in the CFS sample, these data attest to their psychosocial and school dysfunction.

Challenges faced by TVNs in the UK and abroad

Welcome to this issue of the British Journal of Nursing Tissue Viability Supplement. As you would expect of a supplement aimed at nurse specialists in tissue viability, it carries many articles relating directly to the challenges faced by our readers. We are grateful to those of you who take the time to comment on this publication; if you wish to make any points please e-mail me directly on dgray92900@aol.com

Separation of Listeria from cheese and enrichment media using antibody-coated microbeads and centrifugation

An immunoseparation system for the separation of Listeria from enriched cheese samples was developed. The system utilizes polystyrene microbeads (3.8 microm in diameter) coated with covalently bound anti-Listeria genus-specific antibody. The beads were incubated with cheese enriched in half-Fraser broth and the bead-bacterial complex was separated by centrifugation at 110 g then spread on selective agar plates. Although cross-reactivity with certain Gram-positive bacteria (Staphylococcus saprophyticus and Arthrobacter sp.) was determined, this had no negative effect on capture effectiveness of the beads to Listeria spp. The minimum density of Listeria cells positively detected by immunoseparation with subsequent plating was 10(0) cfu/ml. The application of the separation method facilitates a reduction in the time of Listeria detection in cheese by 2 days without affecting the sensitivity.

Effect of prophylactic transfusion of stored RBCs on oxygen reserve in response to acute isovolemic hemorrhage in a rodent model

BACKGROUND

The storage of RBCs results in a time-related decline in 2,3 DPG that may reduce the ability to unload oxygen (O(2)) to tissue. The objective of this study was to compare the effect that transfusion of stored 2,3 DPG-depleted rat blood (7 days in CPDA-1) had on the O(2) reserve in conscious rats, with that of the transfusion of fresh blood (<2-hour storage).

STUDY DESIGN AND METHODS

Anemic rats (Hb, 80 g/L) received either fresh packed RBCs or stored RBCs to raise Hb levels to 140 g per L. They then underwent isovolemic hemorrhage mimicking surgical blood loss to the point of O(2) supply dependency (OSD). Critical O(2) delivery (DO(2)crit), Hb concentration, and O(2) extraction at OSD were measured in a metabolic chamber.

RESULTS

After transfusion, RBC DPG decreased by 50 percent in the stored-blood group, and the p50 value decreased by 5 mmHg (32.1 +/- 2.5 mmHg vs. 37.5 +/- 3.0). DO(2)crit was similar in the two groups (fresh blood: 2.79 +/- 0.44 mL/min x g(-1); stored blood, 2.99 +/- 0.76 mL/min x g(-1)). The critical Hb concentration at DO(2)crit was higher in the stored-blood group (44 +/- 4 g/L) than in the fresh-blood group (38 +/- 5 g/L); the cardiac index and O(2) extraction ratio in the two groups were not different. Under conditions of severe normovolemic anemia in rats, depletion of DPG and a decrease in p50 had only minor effects on the O(2) reserve. At OSD, under these conditions, O(2) consumption is not limited by diffusion.

CONCLUSION

The physiologic impact of DPG depletion in transfused stored blood on oxygen availability in normal rats appears to be small and may be clinically inconsequential.

A call to examine tissue viability nurses' role

Within this issue of the British Journal of Nursing's Tissue Viability Supplement, we feature the work of Charles Fox on the perceptions that tissue viability nurses have of their role (see Pp. 10–16). The data used in this article was obtained during a marketing survey for a commercial company planning its launch into the wound care market. The survey, although small in sample size, identifies some very interesting points.

Epstein-Barr Virus and HLA-DPB1-*0301 in young adult Hodgkin's disease: evidence for inherited susceptibility to Epstein-Barr Virus in cases that are EBV(+ve)

Cases of Hodgkin's disease (HD) may be distinguished by whether they do [EBV-positive ((+ve)) cases] or do not [EBV-negative ((-ve)) cases] have evidence of EBV DNA in the Reed-Sternberg cells. Only one study has attempted to distinguish epidemiological risk factors for EBV(+ve) and EBV(-ve) HD, and none have compared inherited susceptibility. The present study involves a population-based case series of HD, diagnosed in patients between 16-24 years of age in the United Kingdom (n = 118), of whom 87% were classified by EBV status (EBV(+ve), 19, EBV(-ve), 84). History of infectious illness, EBV antibody titers, and HLA-DPB1 type have been compared in EBV(+ve) and EBV(-ve) cases. Reported infectious mononucleosis was more frequent in EBV(+ve) cases (odds ratio (OR), 5.10; 95% confidence interval (CI), 1.12-24.4). EBV antibody titers to viral capsid antigen were significantly higher in EBV(+ve) cases (P for trend = 0.02). Higher proportions of EBV(+ve) (43%) than EBV(-ve) (31%) cases typed positive for HLA-DPB1*0301, but this was not statistically significant; the association of infectious mononucleosis with EBV(+ve) cases was stronger in this HLA subgroup (OR, 17.1; 95%CI, 1.06-1177) than in other cases (OR, 1.24; 95% CI, 0.02-15.4). Although these results are based on small numbers of HD cases, they provide suggestive evidence that the etiology of EBV(+ve) HD may involve inherited susceptibility to EBV.

Prenatal diagnosis of esophageal atresia using sonography and magnetic resonance imaging

BACKGROUND

The diagnosis of esophageal atresia may be suspected on prenatal ultrasound scan in fetuses with a small or absent stomach or unexplained polyhydramnios. However, these findings are thought to have a low positive predictive value and clinical decisions affecting timing or site of delivery may be made erroneously. The authors evaluated the accuracy of fetal sonography followed by magnetic resonance imaging (MRI) for the diagnosis of this lesion.

METHODS

Fetuses considered to be at risk for esophageal atresia based on detailed obstetric sonography underwent fetal MRI using a single-shot rapid-acquisition technique, and the T(2)-weighted images were evaluated prospectively. Scans were considered to be positive if the proximal esophagus was dilated, and the distal esophagus was not seen and negative if the esophagus was visualized throughout its length.

RESULTS

Ten fetuses underwent MRI scanning. All had a small or absent stomach bubble with unexplained polyhydramnios. Four scans were considered to be negative for esophageal atresia; all 4 were found to have a normal esophagus after delivery. Six scans were considered to be positive; 5 had esophageal atresia (2 with tracheoesophageal fistula and 3 without), and one had a neurologic syndrome with a normal esophagus.

CONCLUSIONS

Magnetic resonance imaging appears to be accurate for establishing or ruling out a prenatal diagnosis of esophageal atresia, and should be considered in fetuses who are at high risk based on ultrasound findings.

Overview of protein expression by mammalian cells

This unit reviews the stages involved in protein production in mammalian cells using a stable-expression approach. Choice of cell type is discussed, as is transfection of the host cells, methods for selection and amplification of transformants, and growth of cells at appropriate scale for protein production. Since post-transcriptional modification and intracellular protein transportation are important features of recombinant-protein production in mammalian cells, some description of these mechanisms is included.

Sharing information and clinical experiences

Welcome to the second issue of the BJN supplement for nurse specialists in the field of tissue viability. Many thanks to all those who communicated their thoughts on the first issue and to those who have suggested ideas for articles.

Nutrition and wound healing: what is the link?

Given the important role played by nutrients in wound healing, all patients with wounds should receive a nutritional assessment. Action must then be taken to address any deficiency.

How do we make the NHS value our services?

The role played by tissue viability nurse specialists (TVNSs) within the NHS is, for the most part, unrecognized. The NHS would be a poorer place were it not for the work carried out by TVNSs who ensure that high-risk patients receive pressure-reducing equipment, that wounds are managed efficiently and that the NHS receives value for money wherever possible. We perform a key role within the NHS. So whose fault is it that our contribution is unrecognized? There is no doubt we have created a rod for our own backs because of our failure to quantify and highlight our work. It therefore follows that we hold the key to changing this situation.

Rewiring of CD40 is necessary for delivery of rescue signals to B cells in germinal centres and subsequent entry into the memory pool

Memory B-cell development is impaired by in vivo blockade of the CD40-CD40 ligand (CD40L) interaction using human Fc immunoglobulin G1 (IgG1)-mouse CD40 fusion protein (CD40-Ig); however, germinal centre (GC) formation is not. We show here that the block in B-cell differentiation in these mice is at the stage of rescue from apoptosis and exit from the GC. Thus, GC from CD40-Ig-treated mice contain a three- to fourfold higher level of apoptotic cells than found in control mice injected with human IgG1 alone. This increase in apoptosis is not caused by a blockade of the CD40L-mediated rescue signal but is the result of an intrinsic defect of GC B cells in CD40-Ig-treated mice to receive rescue signals via CD40. While anti-CD40 stimulation maintained the viability in culture of GC B cells from control mice, it did not rescue GC B cells from CD40-Ig-treated mice. This data is consistent with the notion that a 'rewiring' of the CD40 molecule is induced by CD40 ligation early in the response and is necessary to allow B-cell rescue from apoptosis when they subsequently enter the GC.

Coronary heart disease inequalities: deaths and the socio-economic environment in Nottingham, England

We undertook an ecological study to investigate differences in coronary heart disease mortality within Nottingham health authority, England, to establish whether coronary mortality varied according to socio-economic status, and how mortality rates changed over a decade. An index of socio-economic status was developed from Census variables. This was used to group enumeration districts into quintiles to examine mortality inequalities. Death rates fell from 1982 to 1992, but at differential rates between the socio-economic zones. The gap in death rates between the most disadvantaged and advantaged areas widened in most population groups.

Comparison of two skin care regimes for incontinence

It is estimated that 30% of nursing home residents may be faecally incontinent, with those figures rising to 60% for patients in long-stay hospitals (Royal College of Physicians, 1995). Maintaining skin integrity for these patients can be complex. With little clinical information to support carers, choosing a skin care regime that maintains skin integrity for this high-risk group can be difficult. This study aims to compare two recognized skin care regimes, used in the cleansing of patients' skin following an episode of incontinence, and their impact on patients' skin integrity. A total of 93 patients were recruited to the trial from five care of the elderly or dependent service providers. The subjects were randomly allocated to either group A (soap and water; n = 49), or group B (Clinisan (Vernacare); n = 44). Initially, 33 patients in both groups started with healthy skin. However, the results of the final assessment identified only 17 subjects in group A remaining healthy, compared with 27 in group B.

Signals that initiate somatic hypermutation of B cells in vitro

Somatic hypermutation is initiated as B lymphocytes proliferate in germinal centers. The signals that switch on the mutation process are unknown. We have derived an in vitro system to define signals that will initiate mutation in normal, naive splenic B cells. We find that three signals are required to allow detection of somatic mutation in vitro; these are anti-Ig, anti-CD40, and anti-CD38. If any one of these is omitted, mutation remains off. We show that CD40 is obligatory in vivo, as CD40 knockout mice exhibit no Ag-driven mutation. In contrast, CD38 is not, as CD38 knockout mice mutate normally. We believe that, in vitro, CD38, in combination with other stimuli, drives extensive cell division, allowing the detection of mutated sequences. However, in germinal centers in vivo, proliferative activity is instigated by a different molecule. This is the first demonstration of the initiation of hypermutation in vitro with normal splenic B cells using defined stimuli.

An MRP system for surgical linen management at a large hospital

Materials Requirements Planning (MRP) has been used extensively in manufacturing and other industries to improve on-time delivery and to reduce costs. In this paper, we illustrate how an MRP-type system was developed to monitor surgical linen at a large teaching hospital. We also describe a bar-code scanning 'tag and recapture' study to estimate total inventory. The hospital implemented several changes based upon our recommendations that resulted in time savings and a smoother flow of materials throughout the surgical linen supply chain.

Geographical distribution of cardiac arrest in Nottinghamshire

BACKGROUND

to analyse the incidence of out-of-hospital cardiac arrest in Nottinghamshire; to ascertain its geographical distribution; and to determine whether the geography of coronary heart disease mortality and out-of-hospital cardiac arrest are the same.

METHODS AND RESULTS

population based, retrospective study in the County of Nottinghamshire with a total population of 993,914 in an area of 2183 km2 divided into 191 electoral areas. In the 4 years from 1 January, 1991 to 31 December, 1994, 1634 patients sustained a cardiac arrest attributed to a cardiac cause (International Classification of Diseases codes 390-414 and 420-429) and were attended by the Nottinghamshire Ambulance Service. The overall crude mean incidence rate of community cardiac arrest per electoral area was 40.2 per 100,000 population (range 0-121.2). Thirteen electoral areas, relatively deprived according to the Townsend score, had a significantly greater than expected incidence rate of cardiac arrest (median of 75.6/100,000 per electoral area; interquartile range (IQR) 65.3, 83.8). Twelve relatively affluent electoral areas had a significantly lower than expected incidence rate (median of 18.5/100,000 per area (IQR 13.0, 28.7). After adjusting for deprivation index, there were no differences in coronary heart disease (CHD) mortality and community cardiac arrest in urban and rural electoral areas. Apart from response times by ambulance crews, the events that follow the cardiac arrest such as bystander resuscitation, ventricular fibrillation found as the presenting rhythm and survival were similar in all electoral areas.

CONCLUSIONS

increasing level of deprivation is associated with areas of increased incidence of out-of-hospital cardiac arrest in Nottinghamshire, and the effect is apparently different from that on CHD mortality. There is scope for reducing incidence rates of community cardiac arrest and to introduce strategies to improve survival in areas identified as having high rates of community cardiac arrest.

Identification of an interactive effect of beta3- and alpha2b-adrenoceptor gene polymorphisms on fat mass in Caucasian women

Several adrenoceptor subtypes are expressed in adipocytes, which together exert their influence on adipocyte metabolism. Therefore, we specifically examined the interactive effect of Trp64Arg (beta3) and Glu12/Glu9 (alpha2b) adrenoceptor (AR) polymorphisms on energy metabolism and body composition in healthy women with a wide range of body habitus. We genotyped 909 unrelated women (age 55 +/- 12 [mean +/- SD] years, range 19-87; body weight 88 +/- 22 kg, range 40-167; and BMI 33 +/- 8 kg/m2, range 16-64) for Trp64Arg beta3AR and Glu12/Glu9 alpha2bAR variants. We examined the independent effect of the Glu12/Glu9 alpha2bAR variant on body composition and energy balance, in a large cohort of Caucasian women (n = 909). A second goal was to examine the interaction effect of Glu12/Glu9 alpha2bAR and Trp64Arg beta3AR on the same phenotypes. The obesity-related phenotypes studied were as follows: body weight, BMI, fat mass, visceral fat, fat-free mass, resting metabolic rate (RMR), VO2max, leisure time physical activity, and daily energy intake. Body composition and body fat distribution were measured by dual-energy X-ray absorptiometry and radiographic imagery, VO2max by a treadmill test to exhaustion, and RMR by indirect calorimetry. An analysis of covariance indicated that in the entire cohort, there was no significant difference between Glu12/Glu9 alpha2bAR carriers and control subjects for any of the obesity-related phenotypes that were examined. However, we observed a significant interaction effect of the Trp64Arg and Glu12/Glu9 variants on fat mass (P = 0.009) and percent fat (P = 0.016). Age, height, body weight, BMI, fat-free mass, visceral fat, energy expenditure, respiratory quotient, physical fitness, and energy intake were not different among groups. Collectively, these findings support an interaction effect of the two adrenoceptor variants on body fatness in Caucasian women, although the physiological mechanism by which they exert this effect remains to be determined.

Evaluation of an electric bed frame and pressure-reducing mattresses

Pressure ulcers remain a challenge to all healthcare professionals. With the trend towards caring for ill patients in the community there is a need to ensure that equipment used to prevent pressure ulcers in these patients is effective. It is not always appropriate to simply use equipment designed for hospital. This article describes the evaluation of an electric bed frame and three mattresses specifically designed for patients in the community, in either their own homes or nursing home/residential care. The location of this research can reduce the number of participants recruited. In order to compensate for this, three different methods of evaluation were employed - clinical, laboratory and anecdotal - which have produced results relevant to both purchasers and users of the system tested.

The new QUATTRO PLUS mattress replacement system

Since the early development of alternating pressure air mattresses (APAMs) there have been regular alterations in design. These designs have led to improved reliability and performance. This article outlines the changes made by Talley Medical to the QUATTRO PLUS replacement mattress. Improved safety features and design modifications continue the process commenced many years ago which has seen the use of alternating pressure air mattresses become widespread throughout the UK.

Are we drinking in the ‘last chance’ saloon?

The title of this editorial does not refer to the socializing that will be taking place at the Harrogate tissue viability conference in November. It does, in fact, refer to the recent meeting in Leicester of tissue viability nurses (TVNs) from across the UK (please refer to p. 4 for more details).

Circadian variation in witnessed out of hospital cardiac arrest

OBJECTIVES

To examine the effect on circadian variation of out of hospital cardiac arrest according to the underlying aetiology and presenting rhythm of arrest, and to explore strategies that might help to improve survival outcome using circadian variation.

DESIGN

Population based retrospective study.

SETTING

County of Nottinghamshire with a total population of 993 914 and an area of 2183 km(2).

SUBJECTS

Between 1 January 1991 and 3 December 1994, all witnessed cardiac arrests attended by the Nottinghamshire Ambulance Service, of which 1196 patients had a cardiac cause for their arrest (ICD, 9th revision, codes 390-414 and 420-429) and 339 had a non-cardiac cause.

RESULTS

The circadian variation of the cardiac cases was not significantly different from that of non-cardiac cases (p = 0.587), even when adjusted for age, sex, or presenting rhythm of arrest. For cardiac cases, the circadian variation of those who presented with ventricular fibrillation was significantly different from those presenting with a rhythm other than ventricular fibrillation (p = 0.005), but was similar to the circadian variation of bystander cardiopulmonary resuscitation (p = 0.306) and survivors (p = 0.542). Ambulance response time was also found to have a circadian variation.

CONCLUSIONS

There is a common circadian variation of out of hospital cardiac arrest, irrespective of underlying aetiology, where the presenting rhythm is other than ventricular fibrillation. This is different from the circadian variation of cases of cardiac aetiology presenting with ventricular fibrillation. The circadian variation of ventricular fibrillation, and consequently survival, may be affected by the availability of bystander cardiopulmonary resuscitation and the speed of ambulance response.

Cellular interactions involved in Th cell memory

The cellular interactions involved in maintaining CD4+ T cell memory have hitherto not been identified. In this report, we have investigated the roles played by B cells and dendritic cells (DCs) in this process. We show that long-lasting Th cell memory depends on the presence of B cells, but that direct Ag presentation by B cells is not required. Instead, Ag presentation by DCs is critical for the survival of memory Th cells. DCs presenting specific Ag can be detected in animals long after immunization. These findings support a model in which B cells provide an environment in which Ags may be trapped and retained. This Ag is periodically presented to memory CD4+ T cells by DCs, providing an essential survival signal.

Development of a high-performance liquid chromatographic-mass spectrometric assay for the specific and sensitive quantification of Ro 64-0802, an anti-influenza drug, and its pro-drug, oseltamivir, in human and animal plasma and urine

Oseltamivir phosphate (Ro 64-0796/002) is a pro-drug of the anti-influenza neuraminidase inhibitor, Ro 64-0802, and as Tamiflu, has been developed for the treatment of both A and B strains of the disease. This paper describes an HPLC-MS-MS assay for both compounds in plasma and urine which fulfils all of the criteria for a good analytical method. It is sensitive with limits of quantification of 1 and 10 ng/ml for the pro-drug and active neuraminidase inhibitor, respectively. It is both accurate and precise with typical coefficients of variation from some 5,000 quality control samples of approximately +/-3 and +/-6%, respectively. Extensive stability studies have demonstrated the absence of significant problems associated with the decomposition of either compound, although ex vivo hydrolysis of Ro 64-0796 to Ro 64-0802 in rodent plasma has to be prevented by the use of the esterase inhibitor, dichlorvos.

A clinical evaluation of the Transfoam mattress after 4 years

It is recognized that pressure-reducing foam mattresses can be of benefit in the prevention of pressure sores but it is also recognized that more information is required to demonstrate their long-term efficacy (Cullum et al, 1995). It is therefore necessary to evaluate the pressure-reducing capabilities of this type of mattress some years after purchase to evaluate if in fact it can maintain its initial level of performance. This article presents the results of one such study carried out 4 years after the purchase of Transfoam mattresses.

Analysis of immunoglobulin (Ig) isotype diversity and IgM/D memory in the response to phenyl-oxazolone

The distribution of immunoglobulin (Ig) isotypes within specific B cell clones in vivo after immunization is not well defined. Using an IgV(H)/CDR3- and isotype-specific reverse transcription polymerase chain reaction method, we have carried out a survey of the diversification of the isotype in a splenic response to phenyl-oxazolone (phOx) on a chicken serum albumin carrier. The phOx-specific V(H) (V(H)Ox-1 with specific CDR3 motif) is associated with all of the heavy chains (mu, delta, alpha, gamma, and epsilon) after simple immunization with antigen in alum. The kinetics of expression of each isotype are distinct and reproducible. Focusing mainly on the expression of secretory Ig transcripts, IgM, IgG1, and IgE are found after priming, whereas IgD and IgA appear after boosting. Secretory IgD transcripts are found reproducibly at moderate levels and may, therefore, contribute significantly to the secreted Ig response in mice. Most crucially, we find enhanced levels of secretory IgM/V(H)Ox-1 transcripts (with 'phOx-specific' CDR3) after boosting, strongly indicating the existence of IgM memory cells that give rise to an enhanced specific IgM secretion in the secondary response.

Comparison of the SF-36 health survey questionnaire with the Nottingham Health Profile in long-term survivors of a myocardial infarction

BACKGROUND

Health-related quality of life, an important outcome measure in health interventions, can readily be assessed by questionnaire. Two widely evaluated examples are the Short Form 36 (SF-36) and Nottingham Health Profile (NHP) questionnaires, but as yet the discriminatory power of these tools has not been compared in a large population of patients with coronary heart disease.

METHODS

All 4-year survivors of a myocardial infarction, identified from the Nottingham heart attack register, were sent the SF-36, NHP and additionally the Rose angina and dyspnoea questionnaires. Mean scores on the SF-36 and NHP were compared with age- and sex-adjusted norms in patients under and over 65 years. Sensitivity of the respective tools was assessed in distinguishing patients with differing degrees of cardiovascular symptomatology.

RESULTS

In patients under 65 years the SF-36 and NHP differed to the same extent from normative data--scores were lower in the comparable domains physical functioning/mobility, bodily pain/pain and energy/vitality, but not in mental health/emotional reaction scores. In social functioning/social isolation results were disparate--SF-36 scores were lower and the NHP similar to normative data. In patients over 65 years mean scores in all five domains were not significantly different from normative data for either tool. The SF-36 was more sensitive than the NHP at detecting the impact of breathlessness, particularly in patients with mild symptoms. Similarly, the SF-36, but not the NHP, could distinguish the effect of differing degrees of angina severity and frequency on social functioning.

CONCLUSION

At least in myocardial infarction survivors, the SF-36 appears a more sensitive tool and may have benefits for assessing health-related quality of life in this patient group.

Role of B cells in maintaining helper T-cell memory

The cellular interactions involved in maintaining CD4+ T-cell memory have hitherto not been identified. In this report, we have investigated the role played by B cells in this process. We show that that long-lasting helper T-cell memory depends on the presence of B cells, but that direct antigen presentation by B cells is not required. These findings provide new insights into the mechanisms which underlie helper T-cell memory. They also suggest that the efficacy of future vaccines will depend critically on the inclusion of B- as well as T-cell epitopes.

Suppression of temperature fluctuations and energy barrier generation by velocity shear

First measurements of temperature fluctuations in a region of high velocity shear show that absolute and normalized fluctuation levels are reduced across the shear layer, a result that is consistent with weak parallel electron thermal conduction in the electron temperature dynamics. The concomitant reduction of temperature, density, and electric field fluctuations reduces the anomalous conducted and convected heat fluxes.

Oscillations of voltage and resistance in Malpighian tubules of Aedes aegypti

The transepithelial voltage (V(t)) of isolated Malpighian tubules of the yellow fever mosquito Aedes aegypti spontaneously oscillates in more than half the tubules. Typically, V(t) decreases and then rises at a frequency of 2 oscillations/min with a duration of 16 s. In 6 isolated perfused tubules studied in detail, V(t) oscillates between 50.5 mV and 15.7 mV in parallel with (1) oscillations of the transepithelial resistance (R(t)) between 7.61 kOmegacm and 3.63 kOmegacm, (2) oscillations of the basolateral membrane voltage of principal cells between -56.7 mV and -72.2 mV, and (3) oscillations of the apical membrane voltage between 107.2 mV and 87.8 mV. The oscillations are dependent on the Cl concentration in the extracellular solutions. As R(t) decreases during the oscillations V(t) goes to the transepithelial equilibrium potential of Cl (E(cl)) indicating transient changes in transepithelial Cl conductance as the mechanism of voltage and resistance oscillations. Since the largest voltage oscillations take place across the whole epithelium and not across cell membranes, oscillating Cl conductances are localized to a single transepithelial Cl diffusion barrier such as the paracellular pathway. This conclusion is supported by the analysis of electrically equivalent circuits that identify the shunt pathway as the site of oscillating Cl conductances.

Chest pain, enzymes and hypothyroidism

Hypothyroidism is a common disorder and when presenting with classical symptoms and signs is easy to recognise. However, hypothyroidism may present in a manner suggestive of an acute myocardial infarction with an elevated creatine kinase and electrocardiographic abnormalities. We report a case of severe hypothyroidism presenting as a cardiac event whose symptoms and signs dispersed following treatment with thyroxine.

Tryptophan hydroxylase polymorphisms in suicide victims

Both environmental and genetic factors appear to contribute to the risk for suicide. The serotonergic system has been implicated in depression, impulsivity and suicidality. Tryptophan hydroxylase (TPH) is the rate-limiting enzyme in the synthesis of serotonin. Suicide has been associated with polymorphisms in intron 7 of the TPH gene. These alleles were studied in samples from 47 deceased Caucasian males as part of the Utah Youth Suicide Study. A 918 base pair fragment spanning the region of interest was amplified. The A218C polymorphism was visualized by restriction fragment length polymorphism (RFLP) and the A779C was sequenced. Neither A218C nor A779C appeared to be associated with suicide in this population. These results did not change when the sample was stratified by age (10-21 years, 22-31 years) or when violent suicides were selected. The complexity of the phenotype of suicide may reflect multiple biological and social etiologic factors, and poses a worthy challenge for genetic studies.

Chemical and physiological characterization of fluo-4 Ca(2+)-indicator dyes

We have developed fluo-4, a new fluorescent dye for quantifying cellular Ca2+ concentrations in the 100 nM to 1 microM range. Fluo-4 is similar in structure and spectral properties to the widely used fluorescent Ca(2+)-indicator dye, fluo-3, but it has certain advantages over fluo-3. Due to its greater absorption near 488 nm, fluo-4 offers substantially brighter fluorescence emission when used with excitation by argon-ion laser or other sources in conjunction with the standard fluorescein filter set. In vitro, fluo-4 exhibited high fluorescence emission, a high rate of cell permeation, and a large dynamic range for reporting [Ca2+] around a Kd(Ca2+) of 345 nM. We have also developed several Ca(2+)-indicators related to fluo-4 having lower affinities for Ca2+ that are useful in cellular studies requiring quantification of higher [Ca2+]. In a variety of physiological studies of live cells, fluo-4 labeled cells more brightly than did fluo-3, when challenged with procedures designed to elevate calcium levels. Fluo-4 is well suited for photometric and imaging applications that make use of confocal laser scanning microscopy, flow cytometry, or spectrofluorometry, or in fluorometric high-throughput microplate screening assays. Because of its higher fluorescence emission intensity, fluo-4 can be used at lower intracellular concentrations, making its use a less invasive practice.

Mortality of patients admitted with a suspected acute myocardial infarction in whom the diagnosis is not confirmed

AIMS

To examine the survival of patients admitted with a suspected acute myocardial infarction in whom the diagnosis was not confirmed ('possible myocardial infarction').

METHODS AND RESULTS

A cohort study based on the Nottingham Heart Attack Register of 1716 sequential patients discharged alive from two acute teaching hospitals following admission in 1992. The main outcome was mortality following hospital discharge after 5 years of follow-up. Survival of the cohort of patients in whom myocardial infarction was suspected but not confirmed was 58% (95% C.I. 56 to 60%) after 5 years of follow-up, compared with an expected survival of 76% in an age/sex matched general population. Patients with ECG abnormalities that were not diagnostic of myocardial infarction had a 5-year survival of 56%, compared with 77% in those without such changes (P<0.00001). In the 703 patients who died in the first 5 years of follow-up, the cause of death was cardiovascular in at least 53% of cases. Survival following hospital discharge was worse than that in patients discharged alive in the same year following a confirmed myocardial infarction (63% vs 69% after 4 years of follow-up P=0.0016).

CONCLUSION

Patients in this study had a substantially increased risk of death in the 5 years after discharge from hospital, compared with an age- and sex-matched population, and worse than patients discharged following a confirmed myocardial infarction. Almost half of those with ECG changes at the time of their admission died over the next 5 years. As over half of all deaths in this cohort were due to cardiovascular causes, further work is needed to identify patients at high and low risk of subsequent mortality who may warrant investigation and treatment following hospital discharge.

Identifying the risk of death following hospital discharge in patients admitted with a suspected acute myocardial infarction in whom the diagnosis is not confirmed

AIMS

To describe clinical factors, available at the time of discharge, that predicted survival of patients admitted with a suspected acute myocardial infarction in whom the diagnosis was not confirmed.

METHODS AND RESULTS

A cohort study based on the Nottingham Heart Attack Register of 1716 sequential patients discharged alive from two acute teaching hospitals following admission in 1992. The main outcome was identification of high and low mortality risk groups over 5 years of follow-up. Overall 5-year survival was 58% (95% CI 56 to 60%). Having abnormal cardiac enzyme changes or an abnormal ECG that was insufficient to meet established diagnostic criteria of myocardial infarction, or both, identified three groups with a 5 year survival of 77%, 60% or 51%. Multivariate methods were used to develop a risk score from seven variables available at the time of discharge (age, sex, past history of myocardial infarction, ECG abnormalities, cardiac enzyme abnormalities, Killip score of 2 or 3 on admission and being discharged on a diuretic). Quartiles of this risk score then identified four groups with 5 year survival ranging from 89% to 25%.

CONCLUSION

Among the study cohort, it was possible to identify subgroups with a markedly different risk of subsequent mortality from clinical indicators that were readily available at the time of hospital discharge. Risk stratification has the potential to improve targeting of subsequent secondary preventive efforts, but further work is required to ascertain whether cardiovascular risk can be modified through a more intensive approach to management.

Regional variation in alcohol consumption in the Northern Territory

OBJECTIVE

To identify any regional variation in per capita consumption of alcohol and the types of beverages consumed in the NT; and to estimate the relative contributions to consumption by Aboriginal and non-Aboriginal people.

METHOD

Per capita consumption estimates were based on wholesale purchases of alcohol by license and Census population data. Mean levels and the percentages of each beverage type consumed were compared between regions and through time. Estimates of per capita levels of consumption between Aboriginal and non-Aboriginal segments of the population were based on reports of the proportion of frequent and occasional drinkers in each group and the ratio of consumption among Aboriginal and non-Aboriginal drinkers.

RESULTS

Mean quarterly per capita consumption was higher in both the Lower Top End (4.22 litres) and the Central NT (4.04 litres), and less in the Barkly (3.44 litres) than in the Top End (3.55 litres). Over the four-year period, consumption in the Top End rose 6.4%, but dropped 22.5% in the Barkly. In the Lower Top End and the Central NT a larger percentage of alcohol was consumed as cask wine than in the Top End. Before licensing restrictions were introduced, this was also the case in the Barkly. In the NT, per capita consumption among Aboriginal people is approximately 1.97 times, and among non-Aboriginal people about 1.43 times, the national average.

CONCLUSIONS

Alcohol consumption in the NT is greater than in Australia as a whole and there is significant regional variation. The problem is not simply an Aboriginal problem, and a broad range of strategies--including a component to address regional variation--is required to reduce it.

Beating the grog: an evaluation of the Tennant Creek liquor licensing restrictions

OBJECTIVE

To review the effectiveness of, and community attitudes towards, increased restrictions on the availability of alcohol in Tennant Creek.

METHOD

Estimates of quarterly per capita consumption of pure alcohol by persons aged > or = 15 years, admissions data from the local hospital, women's refuge and sobering up shelter, and police data on detentions in custody and common offences were compared for the 12 months prior and 24 months subsequent to the introduction of the restrictions. A random sample survey of residents aged > or = 18 years was conducted to ascertain attitudes towards the restrictions.

RESULTS

Over the two years following the introduction of the restrictions, there was a reduction of 19.4% in annual per capita consumption of pure alcohol. This was accompanied by declines in: hospital admissions for acute alcohol-related diagnostic related groups; and persons taken into police custody and the proportions of offences reported on Thursdays. A majority of survey respondents was in favour of retaining or strengthening the existing restrictions.

CONCLUSIONS

The restrictions were effective in reducing alcohol consumption and acute related harm and had the support of the majority of people in Tennant Creek. On the basis of this evidence, the NT Liquor Commission made a decision to retain them. Restrictions do not provide a simple answer to the problems associated with excessive alcohol consumption. However, they can be an effective part of a broad public health strategy to deal with such problems.

What works? A review of evaluated alcohol misuse interventions among aboriginal Australians

AIMS

To identify which intervention strategies have been effective in reducing excessive consumption of alcohol, and related harm, among some segments of Australia's Aboriginal population.

DESIGN

Items dealing with 'alcohol' and 'evaluation' (27) were identified from the comprehensive electronic data base on Aboriginal alcohol and other drug issues, maintained by Australia's National Centre for Research into the Prevention of Drug Abuse. From these were selected all reports (14) dealing specifically with evaluation of particular intervention projects. These were grouped and systematically reviewed under the broad categories of treatment, health promotion education, acute interventions and supply reduction.

FINDINGS

A broad range of intervention strategies has been employed. However, few systematic evaluations have been undertaken and the methodologies employed have been generally insufficient to allow robust generalization. The impact of most interventions appears limited but, in part, this may be a function of inadequate resourcing and programme support.

CONCLUSIONS

Despite the limitations of the evaluation reports, several conclusions can be tentatively drawn. It appears there is a need to employ a broader range of treatment models and complementary intervention strategies. Interventions are generally inadequately resourced. There is a suggestion that supply reduction interventions may be effective. Most importantly, there is a pressing need for more rigorous evaluation studies in cooperation with Aboriginal community organizations.

The place of general practitioners in the management of out-of-hospital cardiopulmonary resuscitation

BACKGROUND

The involvement of general practitioners in community based resuscitation of out-of-hospital cardiac arrest has been found to be effective in improving survival rates. The aim of the study was to assess the potential for including general practitioners in Nottinghamshire in the resuscitation of out-of-hospital cardiac arrest victims by first determining whether they had the skill, experience and equipment to provide cardio-pulmonary resuscitation in the community; and second to ascertain what proportion of them would be prepared to establish a 'rapid response' scheme for patients requiring resuscitation.

METHODS

A postal questionnaire survey, between March and April 1997, of all 738 general practitioners in Nottinghamshire who serve, in total, a population of 1 million.

RESULTS

A total of 592 general practitioners (80%) responded to our survey. The majority worked in a predominantly urban environment and carried out their own out-of-hours on-call duties. Of them 93% had previous experience in cardiopulmonary resuscitation (median of 3 years), while 72.1% had experience of advanced life support, including use of a defibrillator but not recently (median of 8 years). General practitioners in rural practices were more likely to be trained in advanced life support (ALS), had more recent experience in cardiopulmonary resuscitation (including defibrillation) and were more willing to be involved in any proposed local resuscitation scheme. Only 9% of general practitioners carried a defibrillator when on-call and only 13% had access to a defibrillator within their practice premises. Of the general practitioners surveyed 349 (59%) reported a willingness to participate in a 'rapid response cardiac arrest' scheme and general practitioners who had no formal advanced life support training were as willing to become involved in such a scheme as those who were trained in ALS.

CONCLUSIONS

General practitioners may have an important role to play in improving the survival outcome of out-of-hospital cardiac arrest as many are ALS trained and have recent experience in resuscitation. However, few have access to a defibrillator and many do not have recent experience of defibrillation. Any proposed local resuscitation scheme would be particularly applicable to rural general practitioners as many have recent training in ALS, recent experience in advanced life support and most of all, are more willing to participate in such a scheme.

The Northern Territory's cask wine levy: health and taxation policy implications

OBJECTIVE

To examine the effect of the application, and removal, in the Northern Territory of a levy on the sale of cask wine--a beverage shown to contribute disproportionately to alcohol-related harm.

METHOD

Using data on licensee purchases of alcoholic beverages and ABS population data, estimates were made of per capita consumption of pure alcohol by beverage type. Time series variables were analysed using multiple linear regression analysis.

RESULTS

Prior to the introduction of the levy, quarterly per capita consumption of cask wine among persons aged > or = 15 years was 0.73 litres. During the levy period, this fell to 0.49 litres and following removal of the levy rose to 0.58 litres. Imposition of the levy had no significant effect on the consumption of other beverages.

CONCLUSIONS

Taxation is an effective means of reducing excessive alcohol consumption and related harm.

IMPLICATIONS

In the interests of public health, support should be given to the introduction of a tiered tax based on alcohol content.