Regional variation in accessibility of automated external defibrillators in British Columbia

OBJECTIVES

Bystander-applied Automated External Defibrillators (AED) improve outcomes for out-of-hospital cardiac arrest. AED placement is often driven by private enterprise or non-for-profit agencies, which may result in inequitable access. We sought to compare AED availability between four regions in British Columbia (BC).

METHODS

We identified AEDs (confirmed to be operational) and emergency medical system (EMS)-treated out-of-hospital cardiac arrests (OHCA) from provincial registries. We compared AED availability between BC's four most populous regions. The primary outcome was the total regional weekly accessible AED-hours per 100,000 population. We also examined: AEDs per 100,000 population and per km2, the ratio of AEDs to OHCA, and the distance from each OHCA to the closest AED.

RESULTS

From provincial registries, we included 879 AEDs from BC's four most populous regions, where 9333 EMS-treated OHCA occurred over a 5-year period. The most common AED location types were stores, public community centres, and office buildings. Ten percent of AEDs were accessible for all hours. Weekly accessible AED-hours/100,000 population in the four regions were: 3845, 1734, 1594, and 1299. AEDs/100,000 population ranged from 22 to 48, and AEDs/km2 ranged from 0.0048 to 0.20. The number of OHCAs per AED per year ranged from 1.1 to 2.8. The median OHCA-to-closest AED distance ranged from 503 (IQR 244, 947) to 925 (IQR 455, 1501) metres. The regional mean accessibility of individual AEDs ranged between 59 and 79 h per week.

CONCLUSION

BC's four most populous regions demonstrate substantial variability in AED accessibility. Further benefit could be derived from AEDs if placed in locations accessible all hours. Our data may encourage community planning efforts to use data-based strategies to systematically place AEDs in optimal locations with strategies to maximize accessibility.

Efforts by the Coalition to End Social Isolation and Loneliness

Established in the Fall 2018 and based in Washington, D.C., the Coalition to End Social Isolation & Loneliness brings together dozens of national organizations including consumer groups, community-based organizations, health plans, mental and behavioral health organizations, health care innovators, and many others to lead a multi-stakeholder dialogue to address the crisis of social isolation and loneliness in America. The Coalition focuses on three major areas to achieve this goal: Disseminating research findings, developing and advocating for federal and state legislative and regulatory policy interventions, and leading public awareness events in Washington, D.C. and across the nation. The COVID-19 pandemic has greatly accelerated efforts to engage Congress and the Executive Branch on a range of federal policy priorities, including leveraging and advancing social services and supports, supporting health care delivery to support those who are socially isolated and/or lonely, and advancing federally-funded research initiatives.

Emergency care with lay responders in underserved populations: a systematic review

Objective

To assess the individual and community health effects of task shifting for emergency care in low-resource settings and underserved populations worldwide.

Methods

We systematically searched 13 databases and additional grey literature for studies published between 1984 and 2019. Eligible studies involved emergency care training for laypeople in underserved or low-resource populations, and any quantitative assessment of effects on the health of individuals or communities. We conducted duplicate assessments of study eligibility, data abstraction and quality. We synthesized findings in narrative and tabular format.

Findings

Of 19 308 papers retrieved, 34 studies met the inclusion criteria from low- and middle-income countries (21 studies) and underserved populations in high-income countries (13 studies). Targeted emergency conditions included trauma, burns, cardiac arrest, opioid poisoning, malaria, paediatric communicable diseases and malnutrition. Trainees included the general public, non-health-care professionals, volunteers and close contacts of at-risk populations, all trained through in-class, peer and multimodal education and public awareness campaigns. Important clinical and policy outcomes included improvements in community capacity to manage emergencies (14 studies), patient outcomes (13 studies) and community health (seven studies). While substantial effects were observed for programmes to address paediatric malaria, trauma and opioid poisoning, most studies reported modest effect sizes and two reported null results. Most studies were of weak (24 studies) or moderate quality (nine studies).

Conclusion

First aid education and task shifting to laypeople for emergency care may reduce patient morbidity and mortality and build community capacity to manage health emergencies for a variety of emergency conditions in underserved and low-resource settings.

New Pieces for the Older Americans Act Puzzle

With the passage of the new “Supporting Older Americans Act of 2020,” Congress acknowledged and address several under appreciated issues -the growing social isolation and loneliness of older adults, and the significant role that the aging network does and can play in providing supportive services to older adults with advanced illness (also known as serious illness). This presentation will provide information on these and other pieces of the OAA puzzle.

ADVANCED ILLNESS AND THE AGING NETWORK

This session will provide insights on the many ways that the aging network and the Older Americans Act is able to assist individuals, and their families, who are dealing with a serious or advanced illness.

DEVELOPING A NEW FEDERAL POLICY AGENDA TO ADDRESS SOCIAL ISOLATION AND LONELINESS

The Coalition to End Social Isolation and Loneliness convenes a diverse group of allied stakeholders, including consumer and patient groups, health plans, community-based organizations, private sector researchers and innovators, and others, to address the epidemic of social isolation and loneliness. The Coalition is developing and advocating for bipartisan federal policy solutions to provide individuals the support they need to be socially engaged. This session will describe the role of the Coalition in engaging stakeholders, promoting innovative research, and advocating for policy changes that combat the adverse consequences of social isolation and loneliness and advance approaches and practices that improve social connectedness for all Americans.

Cannabis use as a risk factor for causing motor vehicle crashes: a prospective study

AIM

We conducted a responsibility analysis to determine whether drivers injured in motor vehicle collisions who test positive for Δ-9-tetrahydrocannabinol (THC) or other drugs are more likely to have contributed to the crash than those who test negative.

DESIGN

Prospective case-control study.

SETTING

Trauma centres in British Columbia, Canada.

PARTICIPANTS

Injured drivers who required blood tests for clinical purposes following a motor vehicle collision.

MEASUREMENTS

Excess whole blood remaining after clinical use was obtained and broad-spectrum toxicology testing performed. The analysis quantified alcohol and THC and gave semiquantitative levels of other impairing drugs and medications. Police crash reports were analysed to determine which drivers contributed to the crash (responsible) and which were 'innocently involved' (non-responsible). We used unconditional logistic regression to determine the likelihood (odds ratio: OR) of crash responsibility in drivers with 0 < THC < 2 ng/ml, 2 ng/ml ≤ THC < 5 ng/ml and THC ≥ 5 ng/ml (all versus THC = 0 ng/ml). Risk estimates were adjusted for age, sex and presence of other impairing substances.

FINDINGS

We obtained toxicology results on 3005 injured drivers and police reports on 2318. Alcohol was detected in 14.4% of drivers, THC in 8.3%, other drugs in 8.9% and sedating medications in 19.8%. There was no increased risk of crash responsibility in drivers with THC < 2 ng/ml or 2 ≤ THC < 5 ng/ml. In drivers with THC ≥ 5 ng/ml, the adjusted OR was 1.74 [95% confidence interval (CI) = 0.59-6.36; P = 0.35]. There was significantly increased risk of crash responsibility in drivers with blood alcohol concentration (BAC) ≥ 0.08% (OR = 6.00;95% CI = 3.87-9.75; P < 0.01), other recreational drugs detected (OR = 1.82;95% CI = 1.21-2.80; P < 0.01) or sedating medications detected (OR = 1.45; 95%CI = 1.11-1.91; P < 0.01).

CONCLUSIONS

In this sample of non-fatally injured motor vehicle drivers in British Columbia, Canada, there was no evidence of increased crash risk in drivers with Δ-9-tetrahydrocannabinol < 5 ng/ml and a statistically non-significant increased risk of crash responsibility (odds ratio = 1.74) in drivers with Δ-9-tetrahydrocannabinol ≥ 5 ng/ml.

Risk of injury from drinking: the difference which study design makes

BACKGROUND

The magnitude of risk of injury from drinking, based on emergency department (ED) studies, has been found to vary considerably across studies, and the impact of study design on this variation is unknown.

METHODS

Patients were interviewed regarding drinking within 6 hours prior to the injury or illness event, drinking during the same time the previous week, and usual drinking during the last 30 days. Risk estimates were derived from case-control analysis and from both pair-matched and usual frequency case-crossover analysis.

RESULTS

The odds ratio (OR) based on case-control (2.7; 1.9 to 3.8) was larger than that based on pair-matched case-crossover analysis (1.6; 1.0 to 2.6). The control-crossover estimate suggested the case-crossover estimate was an underestimate of risk, and when this adjustment was applied to the case-crossover estimate, risk of injury increased (OR = 3.2; 1.7 to 6.0). Adjusted case-crossover estimates compared with unadjusted showed the largest proportional increase at 7 or more drinks prior to injury (OR = 7.1; 2.2 to 22.9). The case-crossover estimate based on usual frequency of drinking was substantially larger (OR = 10.7; 8.0 to 14.3) than that based on case-control or pair-matched case-crossover analysis, but less than either when adjusted based on control-crossover usual frequency analysis (OR = 2.2; 1.5 to 3.3).

CONCLUSIONS

The data suggest that while risk of injury based on case-control analysis may be biased, control data are important in providing adjustments derived from control-crossover analysis to case-crossover estimates, and are most important at higher levels of consumption prior to the event.

Lymphotoxin β receptor signaling promotes development of autoimmune pancreatitis

BACKGROUND & AIMS

Little is known about the pathogenic mechanisms of autoimmune pancreatitis (AIP), an increasingly recognized, immune-mediated form of chronic pancreatitis. Current treatment options are limited and disease relapse is frequent. We investigated factors that contribute to the development of AIP and new therapeutic strategies.

METHODS

We used quantitative polymerase chain reaction, immunohistochemical, and enzyme-linked immunosorbent analyses to measure the expression of cytokines and chemokines in tissue and serum samples from patients with and without AIP. We created a mouse model of human AIP by overexpressing lymphotoxin (LT)α and β specifically in acinar cells (Ela1-LTab mice).

RESULTS

Messenger RNA levels of LTα and β were increased in pancreatic tissues from patients with AIP, compared with controls, and expression of chemokines (CXCL13, CCL19, CCL21, CCL1, and B-cell-activating factor) was increased in pancreatic and serum samples from patients. Up-regulation of these factors was not affected by corticosteroid treatment. Acinar-specific overexpression of LTαβ (Ela1-LTαβ) in mice led to an autoimmune disorder with various features of AIP. Chronic inflammation developed only in the pancreas but was sufficient to cause systemic autoimmunity. Acinar-specific overexpression of LTαβ did not cause autoimmunity in mice without lymphocytes (Ela1-LTab/Rag1(-/-)); moreover, lack of proinflammatory monocytes (Ela1-LTab/Ccr2(-/-)) failed to prevent AIP but prevented early pancreatic tissue damage. Administration of corticosteroids reduced pancreatitis but did not affect production of autoantibodies, such as antipancreatic secretory trypsin inhibitor in Ela1-LTab mice. In contrast, inhibition of LTβR signaling reduced chemokine expression, renal immune-complex deposition, and features of AIP in Ela1-LTab mice.

CONCLUSIONS

Overexpression of LTαβ specifically in acinar cells of mice causes features of AIP. Reagents that neutralize LTβR ligands might be used to treat patients with AIP.

Association between CYP2D6 genotype and tardive dyskinesia in Korean schizophrenics

The CYP2D6 gene codes for human cytochrome P450 2D6 enzyme, which is responsible for the metabolism of many psychiatric drugs. In schizophrenic patients treated with neuroleptics, decreased or loss of function CYP2D6 alleles may contribute to the development of tardive dyskinesia (TD), a movement disorder that frequently occurs with chronic neuroleptic treatment. The goal of this study was to determine whether the occurrence of TD is associated with CYP2D6 genotype in a cohort of Korean schizophrenics by employing a CYP450 GeneChip((R)) oligonucleotide microarray and PCR assays to screen for 19 CYP2D6 alleles. Our results revealed that males with at least one decreased or loss of function allele have a moderately greater chance of developing TD than males with only wild-type alleles. Female schizophrenics did not have a significantly greater chance of developing TD. Our results demonstrate the utility of CYP2D6 microarrays to assess genotype status in this Korean cohort.

Abnormal fetal growth is not associated with altered chorionic villous expression of vascular endothelial growth factor mRNA

Altered placental and circulating levels of vascular endothelial growth factor (VEGF) and its receptor (flt-1) may be associated with pre-eclampsia and intrauterine growth restriction (IUGR). The aim of this study was to determine whether chorionic villous VEGF or flt-1 mRNA are altered at early gestation in pregnancies subsequently found to be complicated by abnormal fetal growth. Quantitative reverse transcription-polymerase chain reaction was performed on chorionic villous samples for VEGF and flt-1 using an internal RNA standard. Using the individualized birthweight ratio (IBR), the subjects (n = 51) were divided into three groups; IUGR (IBR <10th centile, n = 6), normal (IBR 10th-90th centiles, n = 41) and macrosomic (IBR >90th centile, n = 4). There was no correlation between the mRNA expression of VEGF(121) or VEGF(165) and gestational age of the normal controls. There was also no difference in the expression of either of the VEGF isoforms between the IUGR or macrosomic groups and the normal controls. Expression of flt-1 was below the detection limit of the assay. In conclusion, we have found that altered chorionic villous expression of VEGF is not associated with the initial stages of development of IUGR or macrosomia.

Constitutive expression of the steroid sulfatase gene supports the growth of MCF-7 human breast cancer cells in vitro and in vivo

Many human breast tumors are driven by high intratumor concentrations of 17beta-estradiol that appear to be locally synthesized. The role of aromatase is well established, but the possible contribution of the steroid sulfatase (STS), which liberates estrogens from their biologically inactive sulfates, has been inadequately assessed and remains unclear. To evaluate the role of STS further, we transduced estrogen-dependent MCF-7 human breast cancer cells with a retroviral vector directing the constitutive expression of the human STS gene. Gene integration was confirmed by Southern hybridization, production of the appropriately sized messenger RNA by Northern hybridization, and expression of functional protein by metabolism of [(3)H]estrone sulfate to [(3)H]estrone. Maximum velocity estimates of estrone formation are 64.2 pmol estrone/mg protein.h in STS-transduced cells (STS Clone 20), levels comparable to those seen in some human breast tumors. Lower levels of endogenous activity are seen in MCF-7 cells (13.0 pmol estrone/mg protein.h) and in cells transduced with vector lacking the STS gene (Vector 3 cells; 12.0 pmol estrone/mg protein.h). 17beta-Estradiol sulfate induces expression of the progesterone receptor messenger RNA only in STS Clone 20 cells, whereas estrone sulfate produces the greatest stimulation of anchorage-independent growth in these cells. STS Clone 20 cells retain responsiveness to antiestrogens, which block the ability of estrogen sulfate to increase the proportion of cells in both the S and G(2)/M phases of the cell cycle. Consistent with these in vitro observations, only STS Clone 20 cells exhibit a significant increase in the proportion of proliferating tumors in nude ovariectomized mice supplemented with 17beta-estradiol sulfate. The primary activity in vivo appears to be from intratumor STS, rather than hepatic STS. Surprisingly, 17beta-estradiol sulfate appears more effective than 17beta-estradiol when both are administered at comparable concentrations. This effect, which is seen only in STS Clone 20 cells, may reflect differences in the cellular pharmacology of exogenous estrogens compared with those released by the activity of intracellular STS. These studies directly demonstrate that intratumor STS activity can support estrogen-dependent tumorigenicity in an experimental model and may contribute to the promotion of human breast tumors.

Relationship of hair calcium concentration to incidence of coronary heart disease

This study was designed to evaluate whether hair calcium concentration reflects the mortality from coronary heart disease on a UK-wide basis and to determine the effect--if any--of environmental factors which might affect calcium metabolism on this relationship. The study was based on our earlier findings of an inverse relationship between hair calcium concentration and that in the intima of the aorta and the association of high aorta calcium with severe alterations to the vessel walls which was found never to co-exist with hair calcium concentrations greater than 700 ppm. Hair samples were collected from 4393 males in an ethically approved study in 40 different health districts. These covered the range in known prevalence of heart disease as reflected in the published standardised mortality ratios (SMR). Data on water hardness were obtained from the Water Authorities and on mean annual sunshine hours from the Meteorological Office. Statistical analysis was by regression and multivariate regression techniques. Hair calcium was determined by XRF analysis and the accuracy validated by means of certified reference samples. Significant relationships were found between health district and county SMR and their respective mean hair calcium concentrations accounting for 37 and 55% of their respective variances in SMR. Water hardness and sunshine hours accounted for 39 and 49% of the variance in mortality from CHD. In combination they accounted for 54% of the variance and with the inclusion of hair calcium 65%. South-east England had the highest hair calcium, the hardest water and the most sunshine hours and the lowest mortality from CHD. The converse was true of Scotland. Hair calcium concentration did reflect the risk of CHD on a population basis and was strongly influenced by both the hardness of the water supply and the annual sunshine hours which also independently affected the SMR for CHD.

Designer egg evaluation in a controlled trial

OBJECTIVE

To evaluate the ability of designer eggs enriched in vitamin E, lutein, selenium (Se) and docosahexaenoic acid (DHA) to deliver micronutrients to the human in a palatable and visually acceptable form.

DESIGN

Double-blind, placebo-controlled trial, two treatment groups balanced for sex and age.

SETTING

Department of Biochemistry and Nutrition, SAC, Scotland.

SUBJECTS

Forty healthy adult volunteers completed the study. Volunteers were recruited among staff of the Scottish Agricultural College Interventions: Volunteers consumed, for 8 weeks, either a designer egg or a normal table egg per day. Fasting blood samples were taken before and at the end of the study.

RESULTS

Consumption of designer eggs enriched in vitamin E, lutein, Se and DHA significantly increased the levels of alpha-tocopherol, lutein and DHA in plasma as compared to the changes found after consumption of normal table eggs, with the largest increases found in plasma lutein (1.88-fold increase). The proportion of DHA was increased in all the main lipid classes of the plasma including triacylglycerol (2.3-fold), free fatty acids (1. 6-fold), cholesteryl ester (1.4-fold) and phospholipid (1.3-fold). Egg consumption did not change Se concentration in plasma, blood pressure, total plasma lipid concentrations or the concentrations of total cholesterol and HDL-cholesterol in plasma.

CONCLUSION

Consumption of designer eggs enriched in vitamin E, lutein, DHA and Se as part of normal diet for 8 weeks effectively increased the blood levels of alpha-tocopherol, lutein and DHA.

SPONSORSHIP

Scottish Office Agriculture, Environment, and Fisheries Department.

Analysis of single-nucleotide polymorphisms in the interleukin-4 receptor gene for association with inflammatory bowel disease

Genetic linkage analysis in families with multiple cases of inflammatory bowel disease (IBD) has mapped a gene which confers susceptibility to IBD to the pericentromeric region of chromosome 16 (IBD1). The linked region includes the interleukin(IL)-4 receptor gene (IL4R). Since IL-4 regulation and expression are abnormal in IBD, the IL4R gene is thus both a positional and functional candidate for IBD1. We screened the gene for single-nucleotide polymorphisms (SNPs) by fluorescent chemical cleavage analysis, and tested a subset of known and novel SNPs for allelic association with IBD in 355 families, which included 435 cases of Crohn's disease and 329 cases of ulcerative colitis. No association was observed between a haplotype of four SNPs (val50ile, gln576arg, A3044G, G3289A) and either the Crohn's disease or ulcerative colitis phenotypes using the transmission disequilibrium test. There was also no evidence for association when the four markers were analyzed individually. The results indicate that these variants are not significant genetic determinants of IBD, and that the IL4R gene is unlikely to be IBD1. Linkage disequilibrium analyses showed that the val50ile and gln576arg variants are in complete equilibrium with each other, although they are separated by only about 21 kilobases of genomic DNA. This suggests that a very dense SNP map may be required to exclude or detect disease associations with some candidate genes.

The effect of oral selenium supplementation on human sperm motility

OBJECTIVES

To determine whether the decline in selenium intake and selenium status in men in the West of Scotland might be a contributory factor to male subfertility.

PATIENTS AND METHODS

Two semen samples were collected from patients attending a subfertility clinic and those patients with samples showing reduced motility were invited to participate in an ethically approved double-blind clinically controlled trial with informed consent. Sixty-nine patients were recruited and received either placebo, selenium alone or selenium plus vitamins A, C and E daily for 3 months. A further semen sample was collected at the end of the trial. Plasma selenium status was determined at the beginning and end of the trial period, as was total sperm density and motility.

RESULTS

Plasma selenium concentrations were significantly (P < 0.001) higher in both selenium-treated groups than in controls. No significant effect of treatment on sperm density was recorded. Sperm motility increased in both selenium-treated groups, in contrast to a slight decline in the placebo group, but the difference was not significant. However, as the provision of additional vitamins had no effect on any variable measured it was considered justified to combine the two selenium-treated groups and compare them with the placebo treatment. On this basis, selenium treatment significantly (P < 0.002) increased plasma selenium concentrations and sperm motility (P = 0.023) but sperm density was again unaffected. Five men (11%) achieved paternity in the treatment group, in contrast to none in the placebo group.

CONCLUSION

This trial confirms the result of an earlier study, that selenium supplementation in subfertile men with low selenium status can improve sperm motility and the chance of successful conception. However, not all patients responded; 56% showed a positive response to treatment. The low selenium status of patients not supplemented again highlights the inadequate provision of this essential element in the Scottish diet.

Effect of supplementing the hen's diet with vitamin A on the accumulation of vitamins A and E, ascorbic acid and carotenoids in the egg yolk and in the embryonic liver

1. The effect of a range of supplementations of vitamin A to the laying hen on the concentration of vitamins A, E, ascorbic acid and carotenoids in the maternal liver, the egg yolk and the embryonic liver were investigated. 2. Four groups of 25 Rhode Island Red hens were fed on standard layer-breeder diets with concentrations of supplemented vitamin A ranging from 0 to 120 micrograms/g retinol equivalents from 28 weeks of age. After 3 months, the concentration of vitamin A in the maternal liver was found to be greatly enhanced in proportion to the increasing rates of supplementation with the vitamin. However, the concentration of vitamin E in the maternal liver was markedly reduced by high dietary contents of vitamin A. 3. The concentration of vitamin A in the yolk of the hens' eggs was markedly increased by the dietary supplementation. However, the concentration of both vitamin E and carotenoids in the yolks were significantly reduced by high dietary contents of vitamin A. 4. The concentration of vitamin A in the liver of the embryo and the day old chick was greatly increased by the high concentrations of maternal vitamin A provision. However, the concentration of vitamin E, carotenoids and ascorbic acid in the embryonic/neonatal liver were significantly reduced by high contents of vitamin A in the maternal diet. 5. The susceptibility of the embryonic/neonatal liver to lipid peroxidation was significantly increased as a result of high provisions of maternal vitamin A. 6. It is concluded that excessive provision of vitamin A to the laying hen results in an adverse effect on vitamin E, carotenoids and ascorbic acid in the embryonic/neonatal liver and can compromise the antioxidant status of the progeny.

Effect of supplementation with selenium on whole blood glutathione peroxidase activities and on plasma and tissue selenium concentrations in lambs

In recent years the selenium (Se) intake of the human population of the UK has shown a marked decline from 60 micrograms/d in 1978 to around 30 micrograms/d in 1990 owing largely to a significant reduction in the importation of North American wheat for bread-making flour. Other countries (Finland, for example) in similar situations have instituted fertilization programs in order to raise cereal Se concentrations and thus boost dietary intakes. An alternative approach would be to increase the Se concentration of carcass meat by supplementation of meat animals for a limited period prior to slaughter. A trial was set up with store lambs to evaluate this approach. Sixteen Scottish Blackface lambs were stratified according to live weight and then randomly allocated to one of four treatments: unsupplemented, or 3.5, 7, or 10.5 mg Se/head/wk. After 14 wk, the lambs were sacrificed and samples of shoulder and thigh muscle, liver, and kidney were obtained for analysis. All three treatments effected an increase in whole blood glutathione peroxidase (GSH-Px) and plasma Se concentrations over controls. Shoulder, thigh, and liver Se exhibited a dose-response relationship to treatment, but kidney Se concentrations were unaffected by treatment. Muscle and some organ meat Se concentrations can therefore be increased by supplementation and could contribute to increased human dietary intakes of the element.

Selenium content of convenience and fast foods in Ayrshire, Scotland

Selenium concentrations were determined via hydride generation atomic absorption spectrometry in more than 100 convenience and fast foods including 34 vegetarian dishes. The foods were purchased mainly in Ayrshire, Scotland but some came from other parts of the UK. The results indicate a considerable amount of selenium in certain mushrooms, spinach, fish, offals and chicken-based products. The selenium content of beef- and pork-based products was generally somewhat lower. Vegetarians having a sufficient intake of mushrooms (in particular button and closed cap mushrooms) and spinach do not seem to be at risk of selenium deficiency provided of course that the selenium in mushrooms, in particular, is bioavailable.

Intestinal permeability: an overview

The noninvasive assessment of intestinal permeability in humans has a 20-year history. Because the tests are increasingly used in clinical practice and research and because there is much controversy, we reviewed the literature and outlined the potential and possible shortcomings of these procedures. Data was obtained from personal files and from a systemic search through MEDLINE and EMBASE. The principle of the differential urinary excretion of orally administered test markers is explained with reference to the desired physicochemical properties of the markers and how the principle can be exploited to allow assessment of various other gastrointestinal functions. The use of intestinal permeability tests for diagnostic screen for small bowel disease and assessment of responses to treatment, the pathogenesis of disease, normal intestinal physiology, and the effect of drugs and toxins on the intestine is described and reviewed. The controversy surrounding the anatomic location of the permeation pathways that the markers use is highlighted. Noninvasive tests of intestinal permeability have fulfilled early promises of usefulness in clinical practice and research. There is now a need for integrated research into the basic mechanisms of regulatory control of the intestinal barrier function.

Beard calcium concentration as a marker for coronary heart disease as affected by supplementation with micronutrients including selenium

Hair calcium concentration is biologically regulated and inversely correlated to the concentration in the aorta. Populations generally divide into high and low hair calcium groups which differ significantly from each other. It has been found that about 90% of people who suffer an acute myocardial infarction belong to the low hair calcium group. It follows that raising a person's calcium status from the low to the high group should decrease their risk of coronary heart disease. A trial was set up with four groups of 12 people, randomly allocated to one of the following treatments: placebo; vitamin D; antioxidants; and antioxidants plus vitamin D. Beard samples were collected for two months prior to four months of supplementation and for two months afterwards. Blood samples were collected at the end of the supplementation period. All treatments significantly lowered plasma calcium concentrations but did not significantly affect beard calcium concentrations due, primarily, to some large individual fluctuations. Within the limitations of the experiment the combined treatment was the most effective as it was the only one to raise beard calcium levels for the duration of the supplementation period. A higher rate of vitamin D supplementation [i.e., > 50% recommended daily allowance (RDA)] might have established clear differences but larger group sizes would also have been helpful. Of the unsupplemented subjects 80% had plasma selenium concentrations of < 90 micrograms l-1 in contrast to only 10% of supplemented ones.(ABSTRACT TRUNCATED AT 250 WORDS)

Breast cancer gene therapy: transgenic immunotherapy

A number of studies have demonstrated that potent anti-tumor immunity can be induced using cytokine gene transfer, a strategy termed transgenic immunotherapy. Our aim is to express cytokine genes in the vicinity of tumor cells, either by transducing tumor cells themselves, or by delivering cytokine-expressing endothelial cells to tumor sites. We compared the ability of cytokine-expressing tumor cells or endothelial cells to inhibit the tumorigenesis of MDA-MB-435 breast cancer cells in athymic nude mice. Retroviral vectors containing either human interleukin 2 (hIL-2) or interleukin 1 (hIL-1 alpha) were used to transduce MDA-MB-435 cells or human umbilical vein endothelial cells (HUVEC). Using a modified MTT bioassay and an ELISA specific for hIL-2, 43 of 70 MDA-MB-435 clones transduced with IL-2 were found to secrete between 100-800 units of IL-2/10(6) cells/24 hr. hIL-2 and hIL-1 alpha-transduced HUVEC secreted 40 ng/IL-2/10(6)/24 hr and 1.8 ng/10(6)/24 hr, respectively. To facilitate in vivo tracking of tumor cells, both nontransduced and IL-2-expressing MDA-MB-435 cells were genetically-marked with the E. coli lacZ gene and selected using flow cytometry. To study in vivo tumorigenicity, cells were injected into the mammary fat pad of athymic nude mice: (1) lacZ/MDA-MB-435 cells injected alone formed tumors in all animals; (2) IL-2-expressing lacZ/MDA-MB-435 cells did not form any tumors; (3) co-inoculation of MDA-MB-435/IL-2, or HUVEC/IL-2, or HUVEC/IL-1 alpha with lacZ/MDA-MB-435 cells prevented or delayed tumor growth.(ABSTRACT TRUNCATED AT 250 WORDS)

The gene therapy of cancer: transgenic immunotherapy

Gene therapy can be defined as the insertion of functional genes into cells to treat a disease. Cellular augmentation, whereby gene transfer confers a novel function to the cell, has proved to be useful in designing strategies for the treatment of cancer. In particular, a variety of cell types may be transduced with immune response genes that are intended to elicit a more effective immune attack against tumor cells. This process has been termed transgenic immunotherapy. Preclinical studies involving the transduction of tumor cells, stromal cells, and lymphocytes with a number of immune response genes have demonstrated potent cytotoxic lymphocyte responses against tumor cells, and in some cases the induction of long-lasting immunity against tumor rechallenge. It is hoped that this form of cancer immunotherapy will permit the development of vaccines effective in eradicating minimal residual disease and immunizing individuals at risk for cancer.

Selenium content of wheat for bread making in Scotland and the relationship between glutathione peroxidase (EC 1.11.1.9) levels in whole blood and bread consumption

The selenium content of the 1989 harvest of wheat used for bread making in Scotland ranged from 0.028 microgram/g dry weight for home-grown wheat to 0.518 microgram/g for Canadian wheat. The tonnage values indicate that 13.8% of the wheat used in bread making came from Canada. This reflects in a calculated dietary intake of 31 micrograms/d which is well below the recommended levels of 70 and 55 micrograms for adult males and females respectively (National Research Council, 1989). The average glutathione peroxidase (EC 1.11.1.9) level in 478 samples of human whole blood was 6.08 (SE 0.065) units/ml. This increased to 6.65 (SE 0.321) in sixty-two subjects consuming brown or wholemeal bread but was unaffected by oily fish consumption. Analysis of a small number of samples of whole milk, eggs and meat indicated slightly higher concentrations than previously published values but this trend was insufficient to compensate for the lower cereal provision of Se.

The influence of a low cobalt intake on the neutrophil function and severity of Ostertagia infection in cattle

Two trials involving housed cattle examined the effect of Co depletion and supplementation on immune status as assessed by the neutrophil function test which measures the ability of isolated neutrophils to kill the yeast Candida albicans. A third trial investigated the extent to which Co status influenced the severity of Ostertagia ostertagi infection. In the first two trials liveweight gains were unaffected until some 40-60 weeks on the low dietary Co intake despite very low serum vitamin B12 values being recorded after 10 weeks. However, the immune status as measured by the neutrophil function test was reduced within 10 weeks of commencing the low Co diet. On administration of Ostertagia ostertagi larvae, Co-depleted cattle showed a greater weight loss than Co-supplemented cattle but showed no difference in the length of the prepatent period, worm egg production or serum gastrin and pepsinogen concentrations. After anthelmintic treatment both groups showed a similar response. It is postulated that the lowered immune response of Co-depleted cattle resulted in the greater severity of the Ostertagia ostertagi infection.

A comparison of serum vitamin B12 and serum methylmalonic acid as diagnostic measures of cobalt status in cattle

In two trials an assessment was made of serum methylmalonic acid as a diagnostic criterion of cobalt status in housed cattle. Despite the small number of animals used the method showed some promise, and normal concentrations are tentatively suggested as being less than 2 mumole/litre, subclinically cobalt deficient 2 to 4 mumole/litre and cobalt-deficient greater than 4 mumole/litre. However, for assessing how cobalt status is likely to influence the rate of liveweight gain of cattle, measurements of both serum methylmalonic acid and vitamin B12 concentrations would appear to be better.

Serum vitamin B12 and methylmalonic acid determinations in the diagnosis of cobalt deficiency in pregnant ewes

Serum vitamin B12 and methylmalonic acid (MMA) concentrations were used to monitor the development of cobalt (Co) deficiency and repletion from the deficient state in housed pregnant hill sheep. Serum MMA concentrations were less variable and provided a more accurate diagnosis of Co deficiency than serum vitamin B12. This was particularly the case for subclinical disease. However, unlike serum MMA, concentrations of the vitamin in serum could be used prognostically. The most precise diagnosis was provided by serum vitamin B12 and MMA data used in conjunction, but where one technique is to be used, serum MMA determinations are preferred.

Duration of effective benefit from administration of graded oral doses of cobalt to sheep

The rapidity and duration of the response of sheep to graded oral doses of cobalt, given as the sulphate or as a cobalt-supplemented anthelmintic Panacur SC, was assessed by the determination of serum vitamin B12 and methylmalonic acid concentrations. The rapidity of the response to the treatments, which ranged from 1 to 250 mg cobalt, was unaffected by dose rate but the effective duration was dose related. There was some evidence of a cumulative effect from repeat treatments of the anthelmintic at three weekly intervals. It is suggested that the optimum inclusion rate for cobalt in anthelmintics lies within the range 21 to 100 mg/treatment.

Evaluation of the efficacy of trace element supplementation of an anthelmintic

The efficacy of the selenium and cobalt contents of a trace element supplemented anthelmintic was evaluated in a series of trials with lambs in Scotland and Northern Ireland. The product was compared with other methods of supplementation and was found to be an adequate source of selenium when administered at monthly intervals. Its cobalt content was shown to be of some nutritional benefit on four of five sites but not as effective as the monthly 250 mg oral cobalt dose, vitamin B12 injection or intraruminal soluble glass bolus treatments also used. No growth responses were obtained and unsupplemented animals generally had an adequate cobalt and selenium status. No toxicity problems were encountered from either element.

Methods of selenium supplementation of ruminants

Three methods of selenium supplementation, by subcutaneous injection, intraruminal pellet and addition to water, were tested in experiments with cattle and a fourth method, oral supplementation of a sodium selenite solution, was evaluated with lambs. All four methods worked effectively for periods ranging from four months to one year after treatment. It is suggested that choice of treatment will depend on the circumstances of each case, including cost, husbandry system and ease of administration.