Compliance-Adjusted Estimates of Aspirin Effects Among Older Persons in the ASPREE Randomized Trial

The Aspirin in Reducing Events in the Elderly (ASPREE) Trial recruited 19,114 participants across Australia and the United States during 2010-2014. Participants were randomized to receive either 100 mg of aspirin daily or matching placebo, with disability-free survival as the primary outcome. During a median 4.7 years of follow-up, 37% of participants in the aspirin group permanently ceased taking their study medication and 10% commenced open-label aspirin use. In the placebo group, 35% and 11% ceased using study medication and commenced open-label aspirin use, respectively. In order to estimate compliance-adjusted effects of aspirin, we applied rank-preserving structural failure time models. The results for disability-free survival and most secondary endpoints were similar in intention-to-treat and compliance-adjusted analyses. For major hemorrhage, cancer mortality, and all-cause mortality, compliance-adjusted effects of aspirin indicated greater risks than were seen in intention-to-treat analyses. These findings were robust in a range of sensitivity analyses. In accordance with the original trial analyses, compliance-adjusted results showed an absence of benefit with aspirin for primary prevention in older people, along with an elevated risk of clinically significant bleeding.

Sex hormones, SHBG and cognitive performance among older Australian women: an observational study

OBJECTIVE

This study aims to explore the associations between sex hormones and cognitive performance in older women.

METHODS

Associations between sex hormones, sex hormone binding globulin (SHBG) and cognitive performance were examined in women aged at least 70 years, without dementia and not using medications that influence sex hormones. Linear and generalized linear regression models included age, body mass index, education, smoking, alcohol, living circumstances, diabetes, hypertension, depression and impaired renal function.

RESULTS

The included 5511 women had a median (interquartile range) age of 73.9 (71.6-77.6) years. No associations were found for estrone, estradiol, testosterone or dehydroepiandrosterone and cognitive performance. SHBG concentrations above quartile 1 (Q1) were significantly inversely associated with processing speed (Q2, β = -0.94, 95% confidence interval [CI] - 1.64 to -0.24, p = 0.009; Q3, β = -0.82, 95% CI -1.53 to -0.10, p = 0.025; and Q4, β = -0.95, 95% CI -1.70 to -0.20, p = 0.013).

CONCLUSIONS

Sex hormones were not associated with cognitive performance. The finding that low SHBG is associated with better processing speed warrants further investigation. The null findings for the sex hormones establish a firm baseline to confidently explore the association between sex hormones and longitudinal cognitive performance in this population.

TRIAL REGISTRATION

International Standard Randomized Controlled Trial Number Register (ISRCTN83772183) and ClinicalTrials.gov (NCT01038583).

Substitution of a Surface-Exposed Residue Involved in an Allosteric Network Enhances Tryptophan Synthase Function in Cells

Networks of noncovalent amino acid interactions propagate allosteric signals throughout proteins. Tryptophan synthase (TS) is an allosterically controlled bienzyme in which the indole product of the alpha subunit (αTS) is transferred through a 25 Å hydrophobic tunnel to the active site of the beta subunit (βTS). Previous nuclear magnetic resonance and molecular dynamics simulations identified allosteric networks in αTS important for its function. We show here that substitution of a distant, surface-exposed network residue in αTS enhances tryptophan production, not by activating αTS function, but through dynamically controlling the opening of the indole channel and stimulating βTS activity. While stimulation is modest, the substitution also enhances cell growth in a tryptophan-auxotrophic strain of Escherichia coli compared to complementation with wild-type αTS, emphasizing the biological importance of the network. Surface-exposed networks provide new opportunities in allosteric drug design and protein engineering, and hint at potential information conduits through which the functions of a metabolon or even larger proteome might be coordinated and regulated.

Driving Protein Conformational Cycles in Physiology and Disease: "Frustrated" Amino Acid Interaction Networks Define Dynamic Energy Landscapes: Amino Acid Interaction Networks Change Progressively Along Alpha Tryptophan Synthase's Catalytic Cycle

A general framework by which dynamic interactions within a protein will promote the necessary series of structural changes, or "conformational cycle," required for function is proposed. It is suggested that the free-energy landscape of a protein is biased toward this conformational cycle. Fluctuations into higher energy, although thermally accessible, conformations drive the conformational cycle forward. The amino acid interaction network is defined as those intraprotein interactions that contribute most to the free-energy landscape. Some network connections are consistent in every structural state, while others periodically change their interaction strength according to the conformational cycle. It is reviewed here that structural transitions change these periodic network connections, which then predisposes the protein toward the next set of network changes, and hence the next structural change. These concepts are illustrated by recent work on tryptophan synthase. Disruption of these dynamic connections may lead to aberrant protein function and disease states.

P4557Factors associated with treatment and control of hypertension in a healthy elderly population free of cardiovascular disease: a cross-sectional study

Introduction

Despite readily available treatments, control of high blood pressure (BP) in the ageing population remains suboptimal. Gaps in understanding the management of high BP amongst the elderly exist, as most studies have been in predominantly middle-aged populations.

Purpose

We explored pharmacological BP lowering treatment and control among elderly hypertensive participants free from overt cardiovascular disease (CVD), and identified factors related to both “untreated” and “treated but uncontrolled” high BP.

Methods

We analyzed baseline data from 19,114 individuals aged ≥65 years enrolled from Australia and the US in the ASPirin in Reducing Events in the Elderly (ASPREE) study. Hypertension was defined as an average systolic/diastolic BP ≥140/90 mmHg and/or use of any BP-lowering medication. `Controlled hypertensives” were those receiving BP-lowering medication and with BP <140/90 mmHg. Descriptive analyses were used to summarize hypertension control rates; logistic regression was used to investigate relationships with treatment and BP control.

Results

Overall, 74% (14,213/19,114) of participants were hypertensive, and of these 29% (4,151/14,213) were untreated. Among those treated, 47% (4,732/10,062) had BP <140/90 mmHg. Participants who were untreated were more likely to be men, have higher educational status, and be in good physical health, and less likely to have significant comorbidities. The factors related to “treated but uncontrolled” hypertension included older age, being men, Black race (versus White), using BP lowering monotherapy and residing in Australia (versus US) (Figure 1).

Conclusion(s)

There were high levels of “untreated” and “treated but uncontrolled” BP, in an otherwise healthy elderly population, suggesting that opportunities for better BP control exist through targeting intervention to high-risk individuals.

Acknowledgement/Funding

National Institute on Aging and the National Cancer Institute at NIH; NHMRC Australia, Monash University, Victorian Cancer Agency (Australia)

P6362Impact of the 2017 AHA/ACC hypertension guideline on hypertension prevalence and cardiovascular risk factors in a healthy older cohort

Background

The 2017 American Heart Association (AHA)/American College of Cardiology (ACC) hypertension guideline recommends a target blood pressure (BP) of <130/80 mmHg regardless of age, which is lower than previously recommended BP goals.

Purpose

We aimed to determine how much the updated classification for high BP would increase the overall prevalence of “hypertension” in an otherwise healthy elderly population. Additionally, we explored the cardiovascular disease (CVD) risk factor distribution in those newly classified “hypertensives” to determine whether the increased prevalence of hypertension was accompanied by an increase in other modifiable CVD risk factors.

Methods

We used baseline data from 19,114 participants (16,703 in Australia and 2,411 in the USA) aged ≥65 years who were enrolled in the ASPirin in Reducing Events in the Elderly (ASPREE) study between 2010 and 2014. Participants were classified as having hypertension using either: (a) pre-2017 thresholds (SBP ≥140 mmHg or mean DBP ≥90 mmHg and/or on anti-hypertensive) or (b) 2017 AHA/ACC guidelines (SBP ≥130 mmHg or DBP ≥80 mmHg and/or on anti-hypertensive). We assessed the presence of cardiovascular disease risk factors such as diabetes, hypercholesterolemia, smoking, obesity, reduced renal function among these hypertensive participants and also estimated their predicted risk over 10 years.

Results

Based on pre-2017 thresholds, 74% of the participants met the criteria for hypertension. Hypertension prevalence increased to 87% when the more stringent 2017 guideline was applied. 29% of this subset of newly classified hypertensive participants did not have any other identifiable traditional CVD risk factors. Further, a significantly lower 10-year predicted cardiovascular risk (22% versus 26%, p<0.001) among those newly classified hypertensive participants was observed in relation to those having hypertension based on pre-2017 guideline (Figure 1).

Figure 1. 10-year predicted CVD risk among hyoertensive and newly classified hypertensive ASPREE participants by presence of CVD risk factor

Conclusion

As expected, the prevalence of hypertension increased among the healthy elderly when applying the new AHA-2017 guideline; however, the increased prevalence occurs despite lack of an accompanying increase in additional CVD risk factors or predicted 10-year risk. Our findings suggest an individualized approach is needed in evaluating high BP among the healthy elderly.

Acknowledgement/Funding

National Institute on Aging and the National Cancer Institute at NIH; NHMRC Australia, Monash University, Victorian Cancer Agency (Australia)

Shaped-bolus protocol reduces contrast medium volume in abdominal CT while maintaining image quality

AIM

To prospectively assess whether bolus shaping to exponentially decrease the contrast medium injection rate leads to alteration in image validity or renal function.

MATERIALS AND METHODS

In this prospective study, patients alternatively received 100 ml contrast medium versus 75 ml via bolus shaping. Image quality was assessed via measurement of attenuation values in the aorta, liver, and spleen and also blinded subjective assessment of image sharpness, low contrast detectability, image noise, and overall quality. Renal function was assessed by change in creatinine levels up to 72 hours post-contrast medium administration.

RESULTS

Of 190 abdominal computed tomography (CT) studies performed in the 3-month period, 98 received the 75 ml dose. There was no significant difference in renal function or objective image quality with a significant improvement in image sharpness in the 100 ml group.

CONCLUSIONS

By using bolus-shaping software, it is possible to maintain objective image quality while reducing the contrast medium load to the patient. This has significant implications regarding clinical practice in decreasing cost and risks associated with iodinated contrast media.

How to … place a lower bonded retainer

Post-orthodontic relapse of lower incisors is a common phenomenon. Sometimes a bonded retainer is fitted to prevent this relapse. In this article, we suggest a handy clinical technique of fitting a lower bonded retainer, which is convenient and easy to carry out.

Seventy-five-million-year-old tropical tetra-like fish from Canada tracks Cretaceous global warming

Newly discovered fossil fish material from the Cretaceous Dinosaur Park Formation of Alberta, Canada, documents the presence of a tropical fish in this northern area about 75 million years ago (Ma). The living relatives of this fossil fish, members of the Characiformes including the piranha and neon tetras, are restricted to tropical and subtropical regions, being limited in their distribution by colder temperatures. Although characiform fossils are known from Cretaceous through to Cenozoic deposits, none has been reported previously from North America. The modern distribution of characiforms in Mexico and southern Texas in the southernmost United States is believed to have been the result of a relatively recent colonization less than 12 Ma. The new Canadian fossils document the presence of these fish in North America in the Late Cretaceous, a time of significantly warmer global temperatures than now. Global cooling after this time apparently extirpated them from the northern areas and these fishes only survived in more southern climes. The lack of early Cenozoic characiform fossils in North America suggests that marine barriers prevented recolonization during warmer times, unlike in Europe where Eocene characiform fossils occur during times of global warmth.

Postmenopausal hormone therapy and regional brain volumes: the WHIMS-MRI Study

OBJECTIVES

To determine whether menopausal hormone therapy (HT) affects regional brain volumes, including hippocampal and frontal regions.

METHODS

Brain MRI scans were obtained in a subset of 1,403 women aged 71-89 years who participated in the Women's Health Initiative Memory Study (WHIMS). WHIMS was an ancillary study to the Women's Health Initiative, which consisted of two randomized, placebo-controlled trials: 0.625 mg conjugated equine estrogens (CEE) with or without 2.5 mg medroxyprogesterone acetate (MPA) in one daily tablet. Scans were performed, on average, 3.0 years post-trial for the CEE + MPA trial and 1.4 years post-trial for the CEE-Alone trial; average on-trial follow-up intervals were 4.0 years for CEE + MPA and 5.6 years for CEE-Alone. Total brain, ventricular, hippocampal, and frontal lobe volumes, adjusted for age, clinic site, estimated intracranial volume, and dementia risk factors, were the main outcome variables.

RESULTS

Compared with placebo, covariate-adjusted mean frontal lobe volume was 2.37 cm(3) lower among women assigned to HT (p = 0.004), mean hippocampal volume was slightly (0.10 cm(3)) lower (p = 0.05), and differences in total brain volume approached significance (p = 0.07). Results were similar for CEE + MPA and CEE-Alone. HT-associated reductions in hippocampal volumes were greatest in women with the lowest baseline Modified Mini-Mental State Examination scores (scores <90).

CONCLUSIONS

Conjugated equine estrogens with or without MPA are associated with greater brain atrophy among women aged 65 years and older; however, the adverse effects are most evident in women experiencing cognitive deficits before initiating hormone therapy.

Cognitive impairment in hemodialysis patients is common

BACKGROUND

Hemodialysis patients are at high risk for cognitive impairment due to their older age and high prevalence of stroke and cardiovascular risk factors.

METHODS

Using a cross-sectional design, the authors measured cognitive function in 374 hemodialysis patients aged 55 years and older and an age-matched comparison group in Minneapolis and St. Paul, MN. Cognitive performance was measured in three domains: memory, executive function, and language. Subjects were classified as having no, mild, moderate, or severe cognitive impairment.

RESULTS

Of 338 subjects who completed testing in at least two of the three cognitive domains, 13.9% (95% CI 10.4, 18.1) were classified with mild impairment, 36.1% (31.0, 41.5) with moderate impairment, 37.3% (32.1, 42.7) with severe impairment, and 12.7% (9.4, 16.8) with normal cognition. Only 2.9% had a documented history of cognitive impairment. Factors associated with severe cognitive impairment on adjusted logistic regression were stroke (adjusted OR [AOR] 1.95; 95% CI 1.08, 3.49; p < 0.03), equilibrated Kt/V > 1.2 (1.67; 1.01, 2.75; p < 0.05), and education >12 years (0.32; 0.14, 0.72; p < 0.01). The AOR for severe cognitive impairment in a random sample of 101 hemodialysis patients vs an age-matched comparison group was 3.54 (1.28, 9.78; p < 0.02).

CONCLUSIONS

Moderate to severe cognitive impairment is common and undiagnosed in hemodialysis patients. Further studies are needed to determine whether dialysis exacerbates the cognitive impairment attributable to underlying disease. Cognitive testing in hemodialysis patients before dialysis initiation and periodically may be warranted.

How to avoid common errors in clinical photography

This paper demonstrates some of the errors commonly seen in both conventional and digital photography when used for clinical purposes, and details how some of these mistakes may be avoided.

Digital records in orthodontics

In this electronic age there is a general move towards keeping digital records, and many trades and professions now use digital images exclusively. In this article, the advantages (and occasional disadvantages) of the use of digital photography, digital radiography and the latest development--digital study models--in orthodontics are discussed.

Evaluation of a PCR/DNA probe colorimetric membrane assay for identification of Campylobacter spp. in human stool specimens

DNA was extracted from 50 human stool specimens using the QIAamp DNA stool minikit. PCR amplification was followed by post-PCR hybridization to DNA probes specific for the Campylobacter genus, Campylobacter jejuni, and Campylobacter coli in a colorimetric membrane assay. Thirty-two of 38 culture-positive specimens were PCR/DNA probe positive for C. jejuni. The assay is rapid and simple and can be applied to stool specimens for the detection of Campylobacter.

The oldest fossil cichlids (Teleostei: Perciformes): indication of a 45 million-year-old species flock

Five closely related species of fossil cichlids collected from an Eocene site in Tanzania, East Africa, represent the oldest known cichlids. The specimens are whole-body, articulated fishes that are extremely well preserved and, therefore, have the potential to add to our knowledge of the history of this family. Modern cichlids are particularly well known for the numerous species flocks of the East African Great Lakes. A great deal of research is ongoing regarding all aspects of the fishes in these flocks, including their evolutionary history The new collection of fossils reported here is interpreted as representing a species flock that arose in a small crater lake. These fossils indicate that cichlids' ability to form species flocks evolved early in the history of this family.

The teaching of occupational and environmental medicine to medical students in Australia and New Zealand

All the medical schools in Australia and New Zealand were surveyed in order to determine the amount of teaching devoted to occupational and environmental medicine in the medical courses in 1998. A 100% response rate was achieved. The results showed that the number of hours devoted to these topics varied widely, but averaged 12.8 h and 10.5 topics. The most significant factor accounting for the variability was the presence on the universities' teaching staff of individuals trained in the practice of occupational medicine. While our findings show a greater time devoted to these topics than those of similar studies in the United States and Britain, the absolute time remains small when compared with the prevalence of occupational medicine problems in the community. There is little congruence in terms of both content and assessment processes between schools.

For four sixes

This article reviews the literature on orthodontic treatment involving extraction of first molars and highlights many of the clinical considerations when treating such cases. Case reports illustrate the potential problems and indicate some solutions.

Differential effects of haloperidol and clozapine on ionotropic glutamate receptors in rats

Despite multiple lines of investigation the effect of neuroleptics on glutamate-mediated neurotransmission remains controversial. To study the effects of typical and atypical neuroleptics on selected parameters of glutamate-mediated neurotransmission, male Sprague-Dawley rats were randomly assigned to a 21-day oral treatment course with vehicle, haloperidol (HDL), or clozapine (CLZ). Coronal slices of rat brain were then incubated with tritiated ligands to measure NMDA, AMPA, and kainate receptor, and glutamate reuptake site density. Regions of interest included the frontal cortex, anterior cingulate cortex, dorsal striatum, ventral striatum, and the nucleus accumbens. CLZ increased the density of AMPA receptors significantly in the frontal and anterior cingulate cortices compared with normal controls. In the dorsal and ventral striatum, and nucleus accumbens as a whole, CLZ-treated rats had a higher AMPA receptor density compared with both the HDL- and vehicle-treated controls. Additionally, within the nucleus accumbens, CLZ-treated rats had a higher density of AMPA receptors compared with the HDL group in the core, and at trend level in the shell. There was a group by region interaction for NMDA receptor density, primarily reflecting the tendency of HDL treated rats to have high receptor densities in the frontal and anterior cingulate cortices. Kainate receptors and glutamate reuptake site densities did not differ significantly across groups. These results suggest a critical role for glutamate in the mediation of atypical antipsychotic drug action in anatomically-specific regions, and further encourage the investigation of glutamate neurotransmitter systems in schizophrenia.

Acyltransferase activities in the yolk sac membrane of the chick embryo

The activities of some enzymes of glycerolipid synthesis and fatty acid oxidation were measured in subcellular fractions of the yolk sac membrane (YSM), an extra-embryonic tissue that mediates the transfer of lipid from the yolk to the circulation of the chick embryo. The activities of monoacylglycerol acyltransferase and carnitine palmitoyl transferase-1 in the YSM (respectively, 284.8+/-13.2 nmol/min/mg microsomal protein and 145.6+/-9.1 nmol/min/mg mitochondrial protein; mean +/- SE; n = 4) at day 12 of development appear to be the highest yet reported for any animal tissue. Also, the carnitine palmitoyl transferase-1 of the YSM was very insensitive to inhibition by malonyl CoA. The maximal activities of glycerol-3-phosphate acyltransferase and diacylglycerol acyltransferase in the YSM (respectively, 26.7+/-2.2 and 36.1+/-2.1 nmol/min/mg microsomal protein) were also high compared with the reported values for various animal tissues. The very high enzymic capacity for glycerolipid synthesis supports the hypothesis that the yolk-derived lipids are subjected to hydrolysis followed by reesterification during transit across the YSM. The monoacylglycerol pathway appears to be the main route for glycerolipid resynthesis in the YSM. The results also suggest that the YSM has the capacity to perform simultaneously beta-oxidation at a high rate in order to provide energy for the lipid transfer process.

Piggyback archwires

Commonly, clinicians' principal tool in the alignment phase of orthodontic mechanotherapy is the nickel-titanium wire. During the course of orthodontic treatment, however, there are times when some segments of the dental arch require flexible wires, while the rest would benefit from rigid wires. In this report, we describe a technique where both of these needs are satisfied simultaneously. Specifically, a segment of nickel-titanium wire is piggybacked onto a stainless steel wire in regions where flexibility is desired. This method eliminates the problems associated with the activation, de-activation forces created along a continuous archwire and might be more economical. Clinical pictures illustrate the point.

Loss of dopamine D2 receptors in Alzheimer's disease with parkinsonism but not Parkinson's or Alzheimer's disease

A significant proportion of patients with Alzheimer's disease (AD) exhibit extrapyramidal features that are referred to as parkinsonism (AD/Park) to distinguish the clinical and pathological features that differ from Parkinson's disease (PD). Previous results from this laboratory have shown that, although the presynaptic components of the dopamine (DA) system are markedly affected in AD/Park, the pathology is not similar to PD (Murray et al. 1995; Joyce et al. 1997). In the present study, we determined whether the parkinsonian symptoms in AD/Park might also reflect changes in numbers of postsynaptic DA receptors. We analyzed the binding of [125I]epidepride biding to DA D2/D3 receptors and [3H]SCH 23390 to D1 receptors by autoradiography in the striatum of six patients with PD, nine patients with AD, seven patients with AD/Park, and 14 neurologically intact control subjects. D2 receptors were reduced in the caudate and putamen of the AD/Park group (by 42 and 27% of controls, respectively) but not reduced in AD or PD. D1 receptors were elevated by 36% in the putamen of the PD group. Dopamine receptor changes are, therefore, not similar in PD, AD, and AD/Park. The elevation in D1 receptors in PD may contribute to the unwanted side effects of L-dopa treatment. The loss of D2 receptors in AD/Park, not observed in AD lacking overt parkinsonian symptomatology, may contribute to the presence of parkinsonian features and lack of responsiveness to L-dopa.

Production of glutathione-coated microtitre plates for capturing recombinant glutathione S-transferase fusion proteins as antigens in immunoassays

Glutathione S-transferase (GST) is commonly used as a fusion partner in producing recombinant proteins and this technology is increasingly being used to produce antigens for use in immunoassays to measure antibodies. To circumvent the requirement to purify such antigens before use, we developed a method for coupling glutathione to microtitre plates so that GST-containing recombinant proteins could be purified and immobilised in one step in a suitable state for immunoassays. This procedure involves covalent linkage (using the heterobifunctional cross-linker sulphosuccinimidyl 4-(p-maleimidophenyl)butyrate) of reduced glutathione through its sulphydryl group to lysine residues of haemoglobin previously immobilised on microtitre plates. Haemoglobin was superior over other proteins tested in giving the lowest non-specific binding; in this regard it was also important to limit the amount of cross-linker used to 0.1 mM. Using glutamic acid decarboxylase as a model antigen, the new affinity capture assay was at least as good as the two-step procedure involving direct adsorption to plates of previously purified antigen; it may have the additional advantage of preserving the antigen in a more native conformation than direct adsorption. The new assay also performed as well as an assay using anti-GST antibodies adsorbed onto plates; glutathione plates, unlike anti-GST plates, will only capture recombinant proteins containing functional GST--a significant point for some recombinant expression systems in which a large proportion of the protein product is insoluble because of incorrect folding.

Intestinal IgA plasma cells of the B1 lineage are IL-5 dependent

Two lineages of B cells, designated B1 and B2 cells, have been identified based upon their origins, anatomical distribution, cell surface markers, antibody repertoire and self-replenishing potential. B1 cells are maintained by self-renewal of cells resident in the peritoneal cavity (PerC) and they utilize a limited repertoire of germline V-region genes, mostly directed against ubiquitous bacterial antigens such as phosphoryl choline (PC). B2 cells are replenished from bone marrow precursors and use a larger repertoire of immunoglobulin V-region genes. Whereas most immunoglobulin A (IgA) plasma cells in the intestine derive from B2 lineage precursors in the Peyer's patch, a subpopulation of Per C-derived B1 cells populate the intestinal lamina propria where they mature into IgA plasma cells. In previous in vivo studies we have shown that whereas IgA+ B2 cells are interleukin (IL)-6 dependent, B1 cells are IL-6 independent. In view of the in vitro evidence that IL-5 is also involved in IgA expression, in the studies reported here we have used IL-5-deficient mice to evaluate the role of IL-5 in vivo in IgA expression in the gut. The results demonstrate that although total IgA cell numbers are only marginally depressed in IL-5-deficient mice, there is a marked selective depletion of IgA+ cells of the B1 lineage in the gut and a corresponding depression in the capacity of these mice to mount an intestinal response to a B1 antigen (PC) but not to a B2 antigen (oralbumin; OVA), reflecting intact B2-derived IgA cell function but a defect in the B1 cell contribution to IgA responses in IL-5 deficient mice. Collectively these data demonstrate differential cytokine regulation of subsets of IgA+ cells in the gut in that IgA+ cells of the B2 lineage are IL-6 dependent but IL-5 independent, but B1-derived IgA+ cells are IL-5 dependent and IL-6 independent.

Cytokine gene expression in murine fetal intestine: potential for extrathymic T cell development

An increasing body of evidence suggests that certain T cell subsets mature extrathymically in the epithelium of the intestine. In the studies reported here, the authors have analysed cytokine/growth factor gene expression, recombinase-activating gene RAG-1 and RAG-2 gene expression and terminal deoxynucleotidyl transferase (TdT) gene expression in mouse fetal intestine and fetal thymus and liver, two known haematopoietic tissues. Stem cell factor (SCF) and interleukin 7 (IL-7) message was abundant in all three tissues during fetal development. IL-2 and IL-4 were not expressed in fetal gut but IL-4 was weakly detected in fetal liver and thymus. IL-9 and IL-13 mRNA was detected in all fetal tissues and IL-15 mRNA was abundant in fetal intestine but only weakly expressed in fetal liver and thymus. mRNA for SCF, IL-7, IL-13 and IL-15 was also detected in fibroblast-like cell lines derived from fetal intestine. RAG-1 and RAG-2 mRNA was detected in all three fetal tissues. TdT mRNA was not detected in fetal gut or liver but was weakly expressed in (fetal day) fd19-20 fetal thymus. Long-term (> 6 weeks) in vitro growth of IEL was achieved by coculturing intraepithelial lymphocytes (IEL) with IL-7-secreting fibroblasts in the presence of SCF and IL-2. The data show that the fetal mouse gut provides a suitable environment for lymphocyte development and receptor rearrangement, similar to fetal thymus and liver, even though expansion of intestinal IEL is delayed until 2-3 weeks after birth.

A postmortem study of frontal cortical dopamine D1 receptors in schizophrenics, psychiatric controls, and normal controls

We tested the hypothesis that aberrant dopaminergic innervation in frontal and cingulate cortices of schizophrenic patients might be revealed by examining dopamine D1 receptor density in these brain regions. A quantitative autoradiographic assay with [3H]-SCH 23390 was performed with samples from schizophrenic patients, normal controls, neuroleptic-treated controls, and suicides. There was a significant elevation in specific binding of [3H]-SCH 23390 in the intermediate layer of the prefrontal cortex from neuroleptic-treated controls (p = .05). Elevated [3H]-SCH 23390 binding in several layers from prefrontal and cingulate cortex was observed in schizophrenic subjects, although these results did not reach statistical significance. When data from subjects who had received neuroleptics (schizophrenics and neuroleptic controls) were compared to subjects who had not received neuroleptics (normal controls and suicides), there was a significant elevation in receptor density in both the prefrontal (p = .05) and cingulate cortices (p = .03). These data suggest that elevated [3H]-SCH 23390 binding in human prefrontal and cingulate cortices may occur with chronic neuroleptic treatment, although increased receptor density that may exist as a feature of psychotic illnesses cannot be excluded.

Distribution of dopamine D1-D4 receptor subtypes in human dorsal vagal complex

The distribution of D1/D5, D2/D3, D2/D3/D4, and individually, putative D2-D4 receptors across the dorsal vagal complex of the human medulla was assessed with quantitative receptor autoradiography. D1/D5 receptors were found in very low levels. D2 receptors were concentrated in the intermediate and medial subnuclei of the nucleus of the solitary tract (NTS), and in the dorsal motor nucleus of the vagus (DMN), while D3 receptors were more homogeneous across the entire NTS, area postrema (AP), and DMN. In contrast, D4 receptors were found almost exclusively in the intermediate and medial subnuclei of the NTS, and in the DMN. These findings suggest that the "D2 family" of receptors is an important component of brain stem mechanisms regulating visceral function, including gastrointestinal systems, such as emesis, along with cardiovascular and pulmonary systems. Compounds with individual selectivity for D2, D3, or D4 receptors may be useful in the manipulation of neural networks regulating these visceral systems.

Prevalence of parkinsonian signs and associated mortality in a community population of older people

BACKGROUND

Older people frequently have signs of parkinsonism, but information about the prevalence of parkinsonism and mortality among those with the condition in the community is limited.

METHODS

A stratified random sample of 467 residents of East Boston, Massachusetts, 65 years of age or older, were given structured neurologic examinations. Using uniform, specified combinations of parkinsonian signs, we estimated the prevalence of four categories of signs--bradykinesia, gait disturbance, rigidity, and tremor--and of parkinsonism, defined as the presence of two or more categories. We did not study Parkinson's disease because it could not be distinguished from other conditions that can cause parkinsonism. Proportional-hazards models were used to compare the risk of death among people with and those without parkinsonism.

RESULTS

One hundred fifty-nine persons had parkinsonism, 301 did not, and 7 could not be classified. The overall prevalence estimates were 14.9 percent for people 65 to 74 years of age, 29.5 percent for those 75 to 84, and 52.4 percent for those 85 and older. With a mean follow-up period of 9.2 years, 124 persons with parkinsonism (78 percent) and 146 persons without (49 percent) died. Adjusted for age and sex, the overall risk of death among people with parkinsonism was 2.0 (95 percent confidence interval, 1.6 to 2.6) times that among people without. Among people with parkinsonism, the presence of gait disturbance was associated with an increased risk of death.

CONCLUSIONS

Parkinsonism is very common among people over the age of 65, and its prevalence increases markedly with age. Parkinsonism is associated with a twofold increase in the risk of death, which is strongly related to the presence of a gait disturbance.

Peritoneal cavity CD5 (Bla) B cells: cytokine induced IgA secretion and homing to intestinal lamina propria in SCID mice

The mouse peritoneal cavity contains a unique population of B cells (Bla) with a high IgM/low IgD ratio, CD5+ (Ly1), MAC-1 + phenotype. These cells arise early in ontogeny, utilize a limited repertoire of immunoglobulin V genes, produce polyreactive IgM antibodies and have been implicated as the source of many auto-reactive immunoglobulins. Recent data from chimeric mice suggest that this B cell population also contains the precursors of many IgA plasma cells found in the lamina propria of the small intestine. In the present study we have investigated the potential of this cell population to secrete IgA (and IgG) in response to various cytokines. IL-5 alone, or in combination with IL-2, greatly enhanced secretion of both IgG and IgA. Cytokine-induced IgA secretion resulted from expansion of a subset of CD5 B cells co-expressing sIgA. Adoptive transfer of CD5 B cells while peripheral lymph nodes contained only IgM+ and some IgG+ B cells. Transfer of CD5+ B cells also reconstituted serum IgM, IgG and IgA and IgG, immunoglobulins characteristic of mucosal and anamnestic responses, when cultured in vitro with the appropriate cytokines. These cells also give rise to IgA plasma cells in the intestinal lamina propria following adoptive transfer to SCID mice, further supporting the hypothesis that cells of this lineage may be important in immune responses at mucosal surfaces.

Differences in intraepithelial lymphocyte T cell subsets isolated from murine small versus large intestine

Intraepithelial lymphocytes (IELs) have been extensively studied in the murine small intestine. However, to date no studies have assessed IEL in the large intestine, despite the marked differences in function and lumenal environment. In the present study, we isolated IEL from both small and large intestine of three mouse strains (BALB/c, C3H/HeN, C57BL/6) and determined the frequency of CD2, CD4, and CD8 expression on CD3+ IEL, as well as the frequency of alpha beta and gamma delta TCR usage and V beta distribution. Higher numbers of IEL/unit length were always isolated from the small intestine (20-30 x 10(6)/5 mice) compared with large intestine (1.1-2.5 x 10(6)/5 mice). Interestingly, IEL from the large intestine of all strains were predominantly alpha beta TCR+ whereas gamma delta TCR+ IELs predominated in small intestine. Large intestinal IELs were mainly CD4+, in both BALB/c and C3H/HeN mouse strains. IELs from large intestine of C57BL/6 mice were mainly CD8+; however, the CD4+ subset was fourfold higher when compared with small intestine IEL. Potential functional differences between IEL subsets was assessed by determining the relative levels of mRNA for IL-1, 2, 4, 5, 10, IFN-gamma, TGF-beta, and TNF-gamma. Similar patterns of IL-1, IFN-gamma and TNF-alpha were seen while more IL-2, IL-4, IL-5, and IL-10 mRNA was noted in large intestinal IEL. Stimulation of C3H/HeJ IEL with anti-CD3 also resulted in higher levels of IL-3/GM-CSF, IL-4, and IL-6 by IEL from large intestine. These results show that marked differences occur among the T cell subsets present in IELs from mouse small and large intestine.

Differences in intraepithelial lymphocyte T cell subsets isolated from murine small versus large intestine

Intraepithelial lymphocytes (IELs) have been extensively studied in the murine small intestine. However, to date no studies have assessed IEL in the large intestine, despite the marked differences in function and lumenal environment. In the present study, we isolated IEL from both small and large intestine of three mouse strains (BALB/c, C3H/HeN, C57BL/6) and determined the frequency of CD2, CD4, and CD8 expression on CD3+ IEL, as well as the frequency of alpha beta and gamma delta TCR usage and V beta distribution. Higher numbers of IEL/unit length were always isolated from the small intestine (20-30 x 10(6)/5 mice) compared with large intestine (1.1-2.5 x 10(6)/5 mice). Interestingly, IEL from the large intestine of all strains were predominantly alpha beta TCR+ whereas gamma delta TCR+ IELs predominated in small intestine. Large intestinal IELs were mainly CD4+, in both BALB/c and C3H/HeN mouse strains. IELs from large intestine of C57BL/6 mice were mainly CD8+; however, the CD4+ subset was fourfold higher when compared with small intestine IEL. Potential functional differences between IEL subsets was assessed by determining the relative levels of mRNA for IL-1, 2, 4, 5, 10, IFN-gamma, TGF-beta, and TNF-gamma. Similar patterns of IL-1, IFN-gamma and TNF-alpha were seen while more IL-2, IL-4, IL-5, and IL-10 mRNA was noted in large intestinal IEL. Stimulation of C3H/HeJ IEL with anti-CD3 also resulted in higher levels of IL-3/GM-CSF, IL-4, and IL-6 by IEL from large intestine. These results show that marked differences occur among the T cell subsets present in IELs from mouse small and large intestine.

Distribution of putative D4 dopamine receptors in postmortem striatum from patients with schizophrenia

The identification of five dopamine receptor subtypes has given the dopamine hypothesis of schizophrenia new life. The D4 receptor is particularly intriguing because it binds clozapine with high affinity. Putative D4 receptors were labeled in postmortem human brain by subtracting the binding of a saturating concentration of 3H-raclopride (6 nM, which labels D2 and D3 receptors) from that labeled by a saturating concentration of [3H]YM 09151-2 (1-1.3 nM, which labels D2, D3, and D4 receptors). In the control brain, putative D4 receptors show a homogenous distribution in striatum and nucleus accumbens. This is also true in schizophrenic brains, although the levels are significantly higher (twofold). These data are inconsistent with mRNA studies that have shown negligible amounts in striatum and accumbens, with modest amounts reported in most of cerebral cortex. These findings suggest that the putative D4 receptors are not synthesized in this region, but are presynaptically localized on striatal afferent terminals. Our findings confirm and extend the report of Seeman et al. (1993). Extension of these findings into the nucleus accumbens is important because of its extensive connections to the limbic system while the putamen is exclusively "motor" striatum.

Damage to dopamine systems differs between Parkinson's disease and Alzheimer's disease with parkinsonism

Parkinsonism occurs in approximately 35 to 40% of patients with Alzheimer's disease (AD) even with little or no neuronal degeneration in the substantia nigra, which in idiopathic Parkinson's disease (PD) results in the severe loss of striatal dopamine transporter sites. It is not known if there is a loss of striatal dopamine transporter sites in AD with coexistent parkinsonism (AD/parkinsonism). We quantified the pattern of these sites in the striatum and midbrain of patients with the clinical diagnosis of PD, AD, and AD/parkinsonism in comparison with a group of age-matched control subjects. We also quantified the number of D2 receptors and the levels of tyrosine hydroxylase in the substantia nigra and ventral tegmental area of the same groups. The results showed that in AD the loss of dopamine transporter sites was restricted to the nucleus accumbens. The loss of these sites in the AD/parkinsonism group was more extensive than in the AD group, with the most severe losses in the rostral caudate and putamen and least in the caudal caudate and putamen. While the PD group showed an equally severe reduction in numbers of sites, the caudal to rostral gradient of loss differed from that in the AD/parkinsonism group. The PD group also showed a marked loss of dopamine transporter sites, tyrosine hydroxylase, and D2 autoreceptors (located on dopamine neurons) in the substantia nigra and ventral tegmental area. In contrast, no reductions in dopamine transporter sites, tyrosine hydroxylase, and D2 autoreceptors were observed in the substantia nigra and ventral tegmental area of the AD or AD/parkinsonism groups. Thus, the loss of striatal dopamine transporter sites in AD/parkinsonism may be related to the clinical parkinsonian symptoms. However, the loss is not simply the result of neuronal degeneration in the substantia nigra, but must derive from other processes.

Localization of dopamine D3 receptors to mesolimbic and D2 receptors to mesostriatal regions of human forebrain

We characterized the binding of [125I]epidepride to dopamine D2-like and D3-like receptors in tissue sections of human striatum. The competition for binding of [125I]epidepride by domperidone, quinpirole, and 7-hydroxy-N,N-di(1-propyl)-2-aminotetralin (7-OH-DPAT) was best fit by assuming one site in the caudate but two sites in nucleus accumbens. Guanosine 5'-[beta, gamma-imido]triphosphate showed a large modulatory influence in agonist inhibition of [125I]epidepride binding in caudate but not in nucleus accumbens. The binding of [125I]epidepride in the presence of 7-OH-DPAT (1000-fold selective for D3-like versus D2-like sites) and domperidone (20-fold selective for D2-like versus D3-like sites) was used to quantify the numbers of D2-like and D3-like receptors in areas of human brain. The distribution of D2-like and D3-like receptors was largely nonoverlapping. Binding of [125I]epidepride to D3-like receptors was negligible in the dorsal striatum but was concentrated in islands of dense binding in the nucleus accumbens and ventral putamen that aligned with acetylcholinesterase-poor striosomes. Binding to D3-like receptors was also enriched in the internal globus pallidus, ventral pallidum, septum, islands of Calleja, nucleus basalis, amygdalostriatal transition nucleus of the amygdala, central nucleus of the amygdala, and ventral tegmental area. Binding of [125I]epidepride to D2 but not D3 receptors was detected in cortex and hippocampus.

Acute delirium and functional decline in the hospitalized elderly patient

BACKGROUND

Delirium is often considered a transient cognitive syndrome. Its effect on long-term physical function, however, has not been well defined.

METHODS

In a prospective study of 325 hospitalized community and nursing home elderly, we analyzed the effect of in-hospital delirium on subsequent physical function. ADL performance was assessed prior to admission, and at 3 and 6 months after hospital discharge.

RESULTS

There was a strong univariate (unadjusted) association between incident delirium and functional decline (p < .02). Delirious subjects lost a mean of almost one ADL, as measured 3 months after hospital discharge. Using multivariate linear regression analysis, with adjusted change in function as the dependent variable, delirium persisted as the sole predictor of loss of function (p = .009) at 3 months after discharge. The functional decline persisted at 6 months after hospital discharge.

CONCLUSION

This finding of a nontransient, perhaps permanent consequence of delirium invites reexamination of the definition of delirium from that of an acute, reversible syndrome to one of acute onset with long-term sequelae.

Induction of phenotypic changes in SCLC cell lines in vitro by hexamethylene bisacetamide, sodium butyrate, and cyclic AMP

BACKGROUND

Hexamethylene bisacetamide (HMBA), sodium butyrate (NaBt), and cyclic AMP (cAMP) have been shown to induce differentiation, which may regulate tumour growth differently from conventional cytotoxic drugs. It was the intention in the present study to determine whether alterations could be induced in the phenotype of small cell lung cancer (SCLC) cell lines with HMBA, NaBt and cAMP, and whether these alterations would correlate with reduced growth in vivo, implying a phenotypic shift from malignancy towards differentiation.

MATERIALS AND METHODS

The cell lines were NCI-H69, H187 and H128. The activity of dopa decarboxylase (DDC), the BB isozyme of creatine kinase (CK-BB), the synthesis of bombesin-like peptide (BLI), and the presence of neurone specific enolase (NSE) and chromogranin were used as markers of the small cell phenotype. Clonogenicity in suspension in agar, and growth as xenografts in nude mice, were used as malignancy-associated properties. Cell proliferation in vitro was determined by cell counting and growth curve analysis.

RESULTS

HMBA, NaBt and cAMP were found to be reversibly cytostatic in liquid culture and pre-exposure reduced the cloning efficiency in agar by 60%-80%. Growth as xenografts was inhibited (three- to five-fold increase in the tumour doubling time), most significantly by NaBt. Effects of phenotypic markers were more complex. The most significant were a two-fold reduction in DDC with NaBt and HMBA, a 50% increase in CK-BB with cAMP, and a 70%-100% increase in secreted BLI with HMBA and cAMP, in NCI-H69 cells. No significant effects were seen on NSE and chromogranin. There was little sign of an interaction with adriamycin and vincristine, although a slight increase was observed in the ID50 of VP-16 following treatment with cAMP.

CONCLUSIONS

NaBt, HMBA and cAMP were cytostatic and inhibited tumour growth, but there was no coordinated response in marker expression that would confirm phenotypic alteration indicative of differentiation. The problem of defining differentiation in SCLC further complicated the analysis. The possibility remains of combining these agents with conventional cytotoxics as there appears to be little antagonistic effect, and other studies have suggested synergism may be possible with correct scheduling.

Visualization of dopamine D3-like receptors in human brain with [125I]epidepride

In sections of human brain containing the striatum (caudate, nucleus, putamen, nucleus accumbens) the competition for binding of [125I]epidepride by compounds with differing selectivity for dopamine D2 and D3 receptors was examined. Domperidone showed higher affinity for D2-like than D3-like sites whereas 7-OH-DPAT (7-hydroxy-2-(N,N-di-n-propylamino)tetralin) and quinpirole demonstrated the reverse selectivity. The pattern of [125I]epidepride binding in the presence of a high concentration of domperidone was negligible in the dorsal striatum but indicated islands of dense binding to D3-like receptors in the nucleus accumbens and ventral putamen.

Identification and characterisation in vitro of cells with a non-SCLC cell-like phenotype derived from a continuous SCLC cell line

Two adherent sublines, H69V and H69VZ, have been isolated from the classic SCLC cell line NCI-H69. Significant morphological differences were observed between the parental and the derivative cell lines. While NCI-H69 grew as densely packed free floating cellular aggregates the derivative lines grew as a monolayer of epithelioid cells. The growth rates of both the derivative lines were faster than the parental line with doubling times closer to non-SCLC cell lines in the derivative lines. Both H69V and H69VZ either express very low levels or do not express neuroendocrine cell markers including L-dopa-decarboxylase (DDC), creatine kinase-BB isoenzyme (CK-BB), bombesin-like immunoreactivity (BLI), neuron specific enolase (NSE), and neurosecretory type dense core granules (DGCs), compared to the parental cell line. All the lines stained positive for epithelial markers such as CAM5.2. LDH isoenzyme and chromosome analyses confirmed the human origin of all the cell lines. Therefore, it appears that cell line NCI-H69 contains stem cell subpopulation capable of generating cells of both small and non-small cell like phenotypes.

Age-related changes in the regulation of behavior by D-1:D-2 dopamine receptor interactions

Functional interactions between D-1 and D-2 dopamine receptor systems appear important in the regulation of psychomotor behavior, and may alter with aging. Male Sprague-Dawley rats of 5 and 20-24 months were challenged with the selective D-2 agonist LY 163502 alone or following pretreatment with the selective D-1 antagonist SCH 23390. Typical sniffing and locomotor responses to LY 163502 alone were significantly reduced in aged animals. Pretreatment with SCH 23390 blocked these typical responses in both young and aged animals, consistent with their regulation by cooperative D-1:D-2 interactions; however, SCH 23390 released a significant excess of atypical limb/body jerking to LY 163502 in aged animals, a response which appears to have its basis in oppositional D-1:D-2 interactions. These results suggest that the net effect of aging on dopaminergic transmission is to reduce tonic activity through D-1 receptors to a greater extent than that occurring through D-2 receptors. As the present aged animals showed a selective loss of striatal D-2 but not of D-1 receptors in radioligand binding studies, such a reduction of D-1-mediated transmission with aging would seem to involve loss of presynaptic function or of postsynaptic mechanisms beyond the D-1 recognition site.

The interaction of clozapine with dopamine D1 versus dopamine D2 receptor-mediated function: behavioural indices

Studies were undertaken to clarify further the mechanism(s) of action of the atypical neuroleptic clozapine, using a behavioural model with the ability to distinguish between relative antagonism of D1 vs. D2 dopamine receptor-mediated function. Pretreatment with low doses of clozapine (2.5-25.0 mg/kg) readily antagonised intense grooming induced by the selective D1 agonist SK&F 77434 (0.75 mg/kg), and in a less consistent manner antagonised hyperactivities induced by the selective D2 agonist LY 163502 (0.05 mg/kg). In animals whose typical responses to SK&F 77434 were antagonised by clozapine, no atypical behaviours such as vacuous chewing emerged. However, in animals whose typical responses to LY 163502 were antagonised by clozapine, a syndrome of atypical limb/body jerking was released. Despite clozapine showing comparable affinities for D1 and D2 receptors in vitro, this behavioural profile shows similarities to that seen when these agonists are given after pretreatment with a selective D1 antagonist, rather than with a selective D2 antagonist or with non-selective neuroleptics. These results suggest that clozapine has some preferential though not selective action in vivo to antagonise D1 dopamine receptor-mediated function.

Propofol for long-term sedation in the intensive care unit. A comparison with papaveretum and midazolam

Thirty-seven patients with a wide range of illnesses were studied during mechanical ventilation of the lungs in an intensive care unit. Fifteen were sedated with a continuous propofol infusion, with analgesia provided by bolus doses of papaveretum. Twelve received a continuous infusion of papaveretum, supplemented by bolus doses of midazolam. The level of sedation was assessed every four hours and measurements were made of haemodynamic and respiratory variables. Levels of sedation were generally satisfactory in both groups. Six patients who received propofol required the use of muscle relaxants, because of their strong respiratory drives, to achieve synchronisation with the ventilator. There was no significant difference in respiratory or haemodynamic variables between the groups, but several patients required inotropic support because of their disease. There was no evidence of inhibition of adrenal steroidogenesis in the propofol group. Propofol can be a useful sedative agent in the intensive care unit, but sedative regimens should be tailored to individual patient requirements.

New putative selective agonists at the D-1 dopamine receptor: behavioural and neurochemical comparison of CY 208-243 with SK&F 101384 and SK&F 103243

Three putative D-1 agonists with nonbenzazepine structures were compared with the prototype benzazepine D-1 partial agonist SK&F 38393 for their behavioural effects in the intact adult rat, and for their relative affinities for D-1 and D-2 dopamine receptors in vitro. SK&F 103243, a restricted conformation analogue of SK&F 38393, and SK&F 101384 (8-Cl-ADTN) showed low affinity for D-1 and D-2 receptors in in vitro binding studies, and failed to induce any behavioural effects on peripheral administration. CY 208-243, an indolophenanthridine derivative, showed appreciable affinity not only for D-1 receptors but also for D-2 receptors, while in behavioural studies it showed some of the characteristics of a partial D-1 dopamine receptor agonist; thus, it failed to promote stereotyped behaviour, but induced episodes of intense grooming which were sensitive to blockade by the D-1 antagonist SCH 23390. No such effect was induced by the selective D-2 agonist RU 24213. CY 208-243 is the first nonbenzazepine which shows some of the properties of a D-1 agonist in the intact adult animal. However, the differences between its in vitro binding characteristics and its functional properties remain enigmatic.

Magnets and orthodontics

The first part of this paper is a literature review of magnets and their uses in orthodontics. The biological safety of magnets is considered and a report is given of experiments carried out on rat osteosarcoma cell line UMR-106. The second part of the paper describes a case where neodynium-iron-boron magnets were used to assist eruption of an unerupted, vertically impacted upper right canine. Previously, space was available for this tooth, but it failed to show signs of eruption. Following surgical attachment of a magnet, and the use of a second magnet attached to an upper removable appliance, rapid eruption occurred producing a favourable position for bonding.

Outcomes of cardiopulmonary resuscitation in the elderly

STUDY OBJECTIVE

To determine the success rate of cardiopulmonary resuscitation in the elderly and to define characteristics of elderly patients for whom cardiopulmonary resuscitation is effective.

DESIGN

Retrospective chart review.

SETTING

Five Boston health-care institutions: two acute-care hospitals; two chronic-care hospitals; and one long-term-care institution.

PATIENTS

Five hundred and three consecutive patients aged 70 and over who received cardiopulmonary resuscitation.

MEASUREMENTS AND MAIN RESULTS

Of 503 patients, 112 (22%) survived initially but only 19 (3.8%) survived to hospital discharge. The poorest outcomes were for patients with unwitnessed arrests (1 of 116 survived), terminal arrhythmias such as asystole and electromechanical dissociation (1 of 237 survived), and patients with cardiopulmonary resuscitation lasting more than 15 minutes (1 of 360 survived). Only 2 (0.8%; CI, 0.0% to 2.0%) of 244 patients with out-of-hospital cardiopulmonary arrests left the hospital alive. Of 259 patients with in-hospital arrests, 17 (6.5%; CI, 3.4% to 9.6%) survived to discharge. Most survivors had ventricular arrhythmias and were resuscitated within minutes. Initial survivors with either impaired consciousness or functional impairment after the arrest had significantly worse chances of survival than patients without these impairments.

CONCLUSION

Cardiopulmonary resuscitation is rarely effective for elderly patients with cardiopulmonary arrests that are either out-of-hospital, unwitnessed, or associated with asystole or electromechanical dissociation.

Crystalloid versus colloid for circulatory preload for epidural caesarean section

Sixty mothers were randomly allocated to receive either 2 litres of crystalloid or 1 litre of colloid solution (hydroxyethyl starch) in order to preload the circulation prior to elective Caesarean section under epidural anaesthesia. There were no differences in the incidence of hypotension, degree of haemodilution, umbilical cord blood gas tensions or umbilical blood osmolalities between the two groups.