The experiences of cardiac arrest survivors and their key supporters following cardiac arrest: A systematic review and meta-ethnography

AIM

To review qualitative studies on the experience of sudden cardiac arrest survival from the perspective of both survivors and their key supporters, including family/close friends.

METHODS

A seven-step meta-ethnography and synthesis of qualitative evidence was undertaken, informed by the Meta-Ethnography Reporting Guidelines (eMERGe). Four major databases were searched (Medline, EMBASE, CINAHL, PsycINFO; January 1995-January 2022, updated July 2023) for qualitative studies exploring survivors' and/or key supporters' experiences of cardiac arrest survival. The Critical Appraisal Skills Programme checklist and Grading of Recommendations Assessment, Development and Evaluation - Confidence in Evidence from Reviews of Qualitative Research (GRADE-CERQual) were applied to evaluate the overall confidence in research findings. Constructs were identified from each paper, informing theme and sub-theme development.

RESULTS

From 15,917 unique titles/abstracts and 196 full-text articles, 32 met the inclusion criteria. Three themes captured the survivors' experiences: 1) Making sense of my cardiac arrest; 2) Learning to trust my body and mind; and 3) Re-evaluating my life. A further three themes reflected key supporters' experiences: 1) Emotional turmoil; 2) Becoming a carer: same person but different me; and 3) Engaging with a new and unknown world. However, limited data and some methodological weaknesses in included studies reduced confidence in several themes. The findings were conceived within the overarching concept of 'negotiating a new normal'.

CONCLUSIONS

The enduring psychosocial and physical sequelae of cardiac arrest survival substantially impacts the lives of survivors and their key supporters, requiring negotiation of their 'new normality'. The need for sense-making, physical and psychological recovery, and the new roles for key supporters should be strong considerations in the development of future interventions.

An international collaborative study to co-produce a patient-reported outcome measure of cardiac arrest survivorship and health-related quality of life (CASHQoL): A protocol for developing the long-form measure

Background

Current measures of health-related quality of life are neither sufficiently sensitive or specific to capture the complex and heterogenous nature of the recovery and survivorship associated with cardiac arrest. To address this critical practice gap, we plan a mixed-methods study to co-produce and evaluate a new cardiac arrest-specific patient/survivor-reported outcome measure (PROM).

Methods

International guidelines have informed a two-stage, iterative, and interactive process.

Stage one will establish what is important to measure following cardiac arrest. A meta-ethnography of published qualitative research and a qualitative exploration of the experiences of survivors and their key supporters will inform the development of a measurement framework. This will be supplemented by existing, extensive reviews describing concepts that have previously been measured in this population. Focus groups with survivors, key supporters, and healthcare professionals, followed by further interviews with survivors and key supporters, will inform the iterative refinement of the framework, candidate items, and PROM structure.

Stage two will involve a psychometric evaluation following completion by a large cohort of survivors. Measurement theory will inform: the identification of items that best measure important outcomes; item reduction; and provide robust evidence of measurement and practical properties.

Discussion

An international, collaborative approach to PROM development will engage survivors, key supporters, researchers, and health professionals from study commencement. Successful co-production of the cardiac arrest survivorship and health-related quality of life (CASHQoL) measure will provide a robust, relevant, and internationally applicable measure, suitable for completion by adult survivors, and integration into research, registries, and routine care settings.

Ethical approval: University of Warwick Biomedical & Scientific Research Ethics Committee (BSREC 22/20-21 granted 10/11/20).

Acupuncture as an intervention to reduce alcohol dependency: a systematic review and meta-analysis

BACKGROUND

Acupuncture has been widely used as a treatment for alcohol dependence. An updated and rigorously conducted systematic review is needed to establish the extent and quality of the evidence on the effectiveness of acupuncture as an intervention for reducing alcohol dependence. This review aimed to ascertain the effectiveness of acupuncture for reducing alcohol dependence as assessed by changes in either craving or withdrawal symptoms.

METHODS

In this systematic review, a search strategy was designed to identify randomised controlled trials (RCTs) published in either the English or Chinese literature, with a priori eligibility criteria. The following English language databases were searched from inception until June 2015: AMED, Cochrane Library, EMBASE, MEDLINE, PsycINFO, and PubMed; and the following Chinese language databases were similarly searched: CNKI, Sino-med, VIP, and WanFang. Methodological quality of identified RCTs was assessed using the Jadad Scale and the Cochrane Risk of Bias tool.

RESULTS

Fifteen RCTs were included in this review, comprising 1378 participants. The majority of the RCTs were rated as having poor methodological rigour. A statistically significant effect was found in the two primary analyses: acupuncture reduced alcohol craving compared with all controls (SMD = -1.24, 95% CI = -1.96 to -0.51); and acupuncture reduced alcohol withdrawal symptoms compared with all controls (SMD = -0.50, 95% CI = -0.83 to -0.17). In secondary analyses: acupuncture reduced craving compared with sham acupuncture (SMD = -1.00, 95% CI = -1.79 to -0.21); acupuncture reduced craving compared with controls in RCTs conducted in Western countries (SMD = -1.15, 95% CI = -2.12 to -0.18); and acupuncture reduced craving compared with controls in RCTs with only male participants (SMD = -1.68, 95% CI = -2.62 to -0.75).

CONCLUSION

This study showed that acupuncture was potentially effective in reducing alcohol craving and withdrawal symptoms and could be considered as an additional treatment choice and/or referral option within national healthcare systems.

Unexpected field-induced phase transitions between ferrielectric and antiferroelectric liquid crystal structures

Liquid crystals are intriguing electrically responsive soft matter systems. We report previously unexplored field-induced changes in the structures of some frustrated liquid crystal phases and describe them theoretically. Specifically, we have discovered using resonant x-ray scattering that the four-layer intermediate smectic phase can undergo either a transition to the ferrielectric (three-layer) phase or to the ferroelectric phase, depending on temperature. Our studies of intermediate phases using electric fields offer a way to test theories that describe ferroelectricity in self-assembling fluids.

Deduction of the temperature-dependent structure of the four-layer intermediate smectic phase using resonant X-ray scattering

A binary mixture of an antiferroelectric liquid-crystal material containing a selenium atom and a highly chiral dopant is investigated using resonant X-ray scattering. This mixture exhibits a remarkably wide four-layer intermediate smectic phase, the structure of which is investigated over a temperature range of 16K. Analysis of the resonant X-ray scattering data allows accurate measurement of both the helicoidal pitch and the distortion angle as a function of temperature. The former decreases rapidly as the SmC* phase is approached, whilst the latter remains constant over the temperature range studied at 8 degrees +/-3 degrees. We also observe that the senses of the helicoidal pitch and the unit cell of the repeating four-layer structure are opposite in this mixture and that there is no pitch inversion over the temperature range studied.

Visual outcomes in children in Malawi following retinopathy of severe malaria

AIM

To investigate whether retinal changes in children with severe malaria affect visual acuity 1 month after systemic recovery.

METHODS

All children with severe malaria admitted to a research ward in Malawi during one malaria season were examined by direct and indirect ophthalmoscopy. Visual acuity was tested in those attending follow up by Cardiff cards, Sheridan-Gardiner single letters, or Snellen chart.

RESULTS

96 (68%) children attended follow up, of whom 83 (86%) had visual acuity measured. Cardiff cards were used in 47 (57%) children, and Sheridan-Gardiner letters or Snellen chart in 29 (35%). There was no significant difference in the mean logMAR visual acuity between groups with or without macular whitening (0.14 versus 0.16, p = 0.55). There was no trend for worse visual acuity with increasing severity of macular whitening (p = 0.52) including patients in whom the fovea was involved (p = 0.32). Six (4.2%) children had cortical blindness after cerebral malaria, and all six had other neurological sequelae. Ophthalmoscopy during the acute illness revealed no abnormalities in four of these children.

CONCLUSION

Retinal changes in severe malaria, in particular macular whitening, do not appear to affect visual acuity at 1 month. This supports the hypothesis that retinal whitening is due to reversible intracellular oedema in response to relative hypoxia, caused by sequestered erythrocytes infected by Plasmodium falciparum. Impaired visual functioning after cerebral malaria is not attributable to retinal changes and appears to be a cortical phenomenon.

Non-equivalent roles of Drosophila Frizzled and Dfrizzled2 in embryonic wingless signal transduction

The highly conserved Wnt family of growth factors is essential for generating embryonic pattern in many animal species [1]. In the fruit fly Drosophila, most Wnt-mediated patterning is performed by a single family member, Wingless (Wg), acting through its receptors Frizzled (Fz) and DFrizzled2 (Dfz2). In the ventral embryonic epidermis, Wg signaling generates two different cell-fate decisions: the production of diverse denticle types and the specification of naked cuticle separating the denticle belts. Mutant alleles of wg disrupt these cellular decisions separately [2], suggesting that some aspect of ligand-receptor affinity influences cell-fate decisions, or that different receptor complexes mediate the distinct cellular responses. Here, we report that overexpression of Dfz2, but not Fz, rescues the mutant phenotype of wgPE2, an allele that produces denticle diversity but no naked cuticle. Fz was able to substitute for Dfz2 only under conditions where the Wg ligand was present in excess. The wgPE2 mutant phenotype was also sensitive to the dosage of glycosaminoglycans, suggesting that the mutant ligand is excluded from the receptor complex when proteoglycans are present. We conclude that wild-type Wg signaling requires efficient interaction between ligand and the Dfz2-proteoglycan receptor complex to promote the naked cuticle cell fate.

Directionality of wingless protein transport influences epidermal patterning in the Drosophila embryo

Active endocytotic processes are required for the normal distribution of Wingless (Wg) protein across the epidermal cells of each embryonic segment. To assess the functional consequences of this broad Wg distribution, we have devised a means of perturbing endocytosis in spatially restricted domains within the embryo. We have constructed a transgene expressing a dominant negative form of shibire (shi), the fly dynamin homologue. When this transgene is expressed using the GAL4-UAS system, we find that Wg protein distribution within the domain of transgene expression is limited and that Wg-dependent epidermal patterning events surrounding the domain of expression are disrupted in a directional fashion. Our results indicate that Wg transport in an anterior direction generates the normal expanse of naked cuticle within the segment and that movement of Wg in a posterior direction specifies diverse denticle cell fates in the anterior portion of the adjacent segment. Furthermore, we have discovered that interfering with posterior movement of Wg rescues the excessive naked cuticle specification observed in naked (nkd) mutant embryos. We propose that the nkd segment polarity phenotype results from unregulated posterior transport of Wg protein and therefore that wild-type Nkd function may contribute to the control of Wg movement within the epidermal cells of the segment.

Protein kinase C isotype expression and regulation of lymphoid cell motility

Lymphocyte migration into inflammatory sites involves a change from a spherical, non-motile phenotype to an irregular, constantly shape-changing, motile phenotype. We have previously shown that lymphocytes are maintained in the non-motile state by the constitutive activity of protein kinase C (PKC). In this paper we have attempted to identify the PKC isotype which regulates these morphological changes by three different approaches. (a) Motile and non-motile T-cell lines were compared for expression of the alpha, beta I, beta II, gamma, delta, epsilon, eta, zeta and theta isotypes by Western blotting. There was no obvious correlation of isotype expression with motility. (b) Two different PKC inhibitors, one specific for classical isotypes, Go6976 and the other GF109203X, which inhibits both classical and non-classical isotypes were compared for induction of motility in non-motile lymphocytes. Only GF109203X induced motility implying that a non-classical isotype is involved. (c) Non-motile lymphocytes were chronically treated with the PKC activator bryostatin and the time courses of induction of motility and downregulation of PKC isotypes were compared. Induction of motility correlated better with downregulation of epsilon, eta and theta than with alpha or beta. It is concluded that the data fit best with the involvement of a non-classical PKC isotype in regulating lymphocyte motility although no association with a particular isotype was found.

Inhibition of protein kinase C results in a switch from a non-motile to a motile phenotype in diverse human lymphocyte populations

Circulating lymphocytes are rounded, non-motile cells which on contact with cytokines, specialized or activated endothelium, acquire a constantly shape-changing, polarized morphology which enables migration into appropriate sites. The biochemical mechanisms which regulate this switch are not understood but the various stimuli may have a common final pathway. In this study we show that protein kinase C (PKC) inhibitors of the bisindolylmaleimide type (GF 109203X, Ro 31-8220, CGP 41,251) induce resting, spherical lymphocytes to change rapidly (< 30 min) into polarized, locomotory cells. This phenomenon was seen with diverse populations of blood T lymphocytes, tonsillar B cells and Jurkat and Molt4 T-cell lines. Consistent with this, down-regulation of PKC by chronic treatment (44 hr) with bryostatin also induced the polarized phenotype in blood lymphocytes and non-motile Molt4 cells. Conversely, treatment of a spontaneously motile subline of Molt4 cells with various PKC activators caused a reversion to the non-motile phenotype within minutes. PKC activation must be sufficient to overcome the effects of a constitutively active phosphatase because bisindolylmaleimide induction of motility could be prevented by pretreatment of the cells with a phosphatase inhibitor, calyculin A. It is concluded that, in resting lymphocytes, chronic activation of a PKC offsets the action of a constitutively active phosphatase and the net result is maintenance of the non-motile state. Agents which alter the kinase/phosphatase balance in favour of dephosphorylation result in induction of the locomotory phenotype.

Effect of serine/threonine kinase inhibitors on motility of human lymphocytes and U937 cells

Mononuclear cell migration across the endothelium and through connective tissue into inflammatory sites is a multi-step process. After adhesion to the endothelium, there is an initial change in shape from spherical to irregular, followed by the migratory phase itself in which the cells constantly change in shape. In this paper we have investigated the possibility that the shape-changing in this latter phase is controlled by serine/threonine phosphorylation. For this purpose, we used a spontaneously shape-changing variant of U937 monocytoid cells as well as human peripheral blood lymphocytes that had been previously activated by anti-CD3. To test the role of phosphorylation in shape-changing, a wide range of serine/threonine kinase inhibitors was tested, including ML-7, KT5720, KT823, H7, H8, staurosporine, calphostin C, sphingosine, bisindolylmaleimide, chelerythrine and KN-62. Only those compounds which inhibited protein kinase C prevented lymphocyte and U937 shape-change and transmigration across polycarbonate filters. However, one specific protein kinase C inhibitor, bisindolylmaleimide, stimulated lymphocyte shape-change. In conclusion, these studies show that activation of a serine/threonine kinase is necessary for the constant shape-changing required for motility of mononuclear cells. The kinase may be a protein kinase C isotype or a closely related enzyme.

Nitric oxide is produced during TNF killing of U937A cells but does not contribute to the cytotoxic process

Proinflammatory cytokines, including TNF, stimulate nitric-oxide free radical production in a variety of tissues through the induction of the enzyme nitric-oxide synthase. As free radicals are considered likely candidates in the cytotoxic action of TNF, we examined nitric oxide production in TNF-sensitive U937A and TNF-resistant U937A/R cells and its potential role in TNF-induced cytotoxicity. TNF stimulated U937A nitrite production through a process that was abolished by the competitive inhibitors of nitric-oxide synthase N-omega-nitro-L-arginine methyl ester (NAME) and N-G-monomethyl-L-arginine (NMMA) without inhibition of TNF-induced cytotoxicity. TNF also increased nitrite production in TNF-resistant U937A/R cells. In addition, the cytotoxic action of TNF was independent of L-arginine substrate availability. Thus, although cytokine-inducible nitric oxide production is emerging as an effective antitumour mechanism, here, TNF clearly exerted potent antitumour activity against U937A cells through a nitric-oxide-independent mechanism.

Interleukin-1 beta effects on cyclic GMP and cyclic AMP in cultured rat islets of Langerhans-arginine-dependence and relationship to insulin secretion

When islets were cultured with interleukin-1 beta (1 or 100 pmol/l) for 12 h in arginine-containing medium, cyclic GMP levels were increased 1.6- and 4.5-fold respectively. The arginine analogue, N-omega-nitro-L-arginine methyl ester, which blocks nitric oxide formation and partially reverses inhibition of insulin secretion by 100 pmol/l interleukin-1 beta, largely, but not completely, blocked generation of cyclic GMP. Treatment of islets with 100 pmol/l interleukin-1 beta for 12 h significantly decreased islet cyclic AMP generation in the absence of isobutylmethylxanthine (from 13.1 +/- 0.7 to 9.3 +/- 0.8 fmol/micrograms islet protein), this fall was arginine-dependent and may have resulted from an effect on a cyclic AMP phosphodiesterase, since it was masked if isobutylmethylxanthine was present. Isobutylmethylxanthine (0.4 mmol/l) reduced the inhibitory potency of interleukin-1 beta in 15 h slightly but significantly from 80.5 to 59.0%. The morpholinosydnonimine SIN-1, which is a nitric oxide donor, inhibited insulin secretion, raised islet cyclic GMP and lowered cyclic AMP; its effects were similar to those of interleukin-1 beta. However, 6-anilinoquinoline-5,8-quinone, [LY83583 (1-10 mumol/l)], inhibited insulin secretion, and significantly decreased cyclic GMP while 8-bromocyclic GMP stimulated insulin secretion. Both low- and high-dose interleukin-1 beta treatment give a large arginine-dependent and a small, yet significant, arginine-independent increase in cyclic GMP. The inhibitory effect of SIN-1 or interleukin-1 beta on insulin secretion seems to depend to a small extent on decreased islet cyclic AMP, though sustained increases in nitric oxide or depleted islet GTP may directly affect the secretory process.

Tumour necrosis factor induction of ELAM-1 and ICAM-1 on human umbilical vein endothelial cells--analysis of tumour necrosis factor-receptor interactions

Induction of the adhesion molecules ELAM-1 and ICAM-1 on endothelial cells is a key pro-inflammatory effect of tumour necrosis factor (TNF). Earlier work in non-human systems has suggested that unlike other cell types, endothelial cells interact with the N-terminus of the TNF molecule, thereby implying novel TNF receptors on endothelial cells. This is also supported by 125I-TNF cross-linking studies on bovine endothelial cells. The present study aimed to see whether TNF induction of ELAM-1 and ICAM-1 on human umbilical vein endothelial cells (HUVECs) involved novel TNF-receptor interactions. Three approaches were employed. First, antibodies directed at different sites on the TNF molecule were tested for inhibition of TNF-induction of ELAM-1 and ICAM-1 on HUVECs. Inhibition was seen only with antibodies reacting with epitopes outside the N-terminal region. Second, an N-terminal TNF peptide (residues 1-26) failed to induce ELAM-1 and ICAM-1 on HUVECs or antagonise TNF induction of these molecules. Third, HUVEC/125I-TNF cross-linking revealed a major complex characteristic of the known 55 kDa TNF receptor: this was confirmed with receptor-specific monoclonal antibodies. It is concluded that (a) the same part of the TNF molecule interacts with TNF-receptors on HUVECs and other cell types and (b) TNF induction of ELAM-1 and ICAM-1 on HUVECs is mediated via the well-characterized 55 kDa TNF receptor.

Inhibition of insulin secretion by interleukin-1 beta and tumour necrosis factor-alpha via an L-arginine-dependent nitric oxide generating mechanism

Inhibition of glucose-induced insulin secretion by interleukin-1 beta (IL-1 beta), or IL-1 beta plus tumour necrosis factor-alpha (TNF-alpha), was less marked when rat islets of Langerhans were cultured for 12 h with these cytokines in L-arginine-free medium as opposed to medium containing L-arginine (1 mM). Inhibition of secretion by IL-1 beta was further alleviated when islets were maintained in L-arginine-free medium supplemented with N-omega-nitro-L-arginine methyl ester (NAME), while synergism between IL-1 beta plus TNF-alpha was completely abolished. Tissue culture medium nitrite levels were raised in islets treated with IL-1 beta or TNF-alpha (48 h). Cytokine-stimulated nitrite production was not observed in islets cultured with NAME (1 mM). In conclusion, an L-arginine-dependent nitric oxide generating mechanism is involved in the inhibition of insulin secretion by IL-1 beta, and accounts for the phenomenon of synergism between IL-1 beta and TNF-alpha.

Inhibition of insulin secretion from rat islets of Langerhans by interleukin-6. An effect distinct from that of interleukin-1

Glucose-induced insulin secretion from islets cultured in the presence of interleukin-6 (IL-6) for 12-24 h was inhibited to a similar extent as when islets were treated with interleukin-1 beta (IL-1 beta). However, unlike IL-1 beta, IL-6 did not potentiate insulin secretion during an acute (30 min) exposure of islets to the cytokine, nor did it inhibit DNA synthesis during a 24 h culture period. A 12 h pretreatment of islets with tumour necrosis factor-alpha (TNF-alpha) combined with IL-1 beta potentiated the inhibitory effect of IL-1 beta on secretion, such that 20 mM-glucose-induced insulin secretion was abolished. No synergistic inhibition of secretion was observed with TNF-alpha and IL-6. However, IL-1 beta and IL-6 were found to inhibit insulin secretion in an additive manner. These results suggest that IL-6 inhibits insulin secretion in a manner distinct from that of IL-1 beta, and that IL-6 is unlikely to mediate the inhibitory effects of IL-1 beta or TNF-alpha on rat islets of Langerhans.

Mechanism of action of growth-hormone-releasing hormone in stimulating insulin secretion in vitro from isolated rat islets and dispersed islet cells

Human growth-hormone-releasing hormone [(1-44)NH2] (hGHRH) was a potent stimulus for insulin release from rat islets of Langerhans in vitro; the optimum concentration used was 10(-11) M. The dose response curves for hGHRH effects on insulin secretion were notably different in intact islets of Langerhans compared to cultured dispersed islet cells. Pancreatic islets responded to a very low hGHRH concentration (10(-12) M), but at a higher hGHRH concentration (10(-9) M) no stimulation of insulin release was observed. When somatostatin antiserum was included in the incubation medium, hGHRH (10(-9) M) stimulated insulin release from intact islets. In cultured dispersed islet cells, which are principally insulin-secreting B cells, hGHRH directly and potently stimulated insulin release even at a concentration of 10(-9) M. Addition of somatostatin (10(-7), 10(-8) M) significantly reduced the hGHRH-induced insulin-secretory responses of dispersed islet cells. hGHRH (10(-11)-10(-9) M) raised islet cAMP levels; individually, hGHRH and theophylline exerted positive effects on insulin release, their combined effect was greater than that caused by either one. We conclude that hGHRH directly affects insulin secretion in vitro by a cAMP-dependent mechanism, and that the difference in responses of intact islets versus islet cells to increasing concentrations of hGHRH may be related to hGHRH-induced release of somatostatin in intact rat islets.