Persistent resetting of the cerebral oxygen/glucose uptake ratio by brain activation: evidence obtained with the Kety-Schmidt technique

Global cerebral blood flow (CBF), global cerebral metabolic rates for oxygen (CMRO2), and for glucose (CMRglc), and lactate efflux were measured during rest and during cerebral activation induced by the Wisconsin card sorting test. Measurements were performed in healthy volunteers using the Kety-Schmidt technique. Global CMRO2 was unchanged during cerebral activation, whereas global CBF and global CMRglc both increased by 12%, reducing the molar ratio of oxygen to glucose consumption from 6.0 during baseline conditions to 5.4 during activation. Data obtained in the period following cerebral activation showed that the activation-induced resetting of the relation between CMRglc and CMRO2 persisted virtually unaltered for > or = 40 min after the mental activation task was terminated. The activation-induced increase in cerebral lactate efflux measured over the same time period accounted for only a small fraction of the activation-induced excess glucose uptake. These data confirm earlier reports that brain activation can induce resetting of the cerebral oxygen/glucose consumption ratio, and indicate that the resetting persists for a long period after cerebral activation has been terminated and physiologic stress indicators returned to baseline values. Activation-induced resetting of the cerebral oxygen/glucose uptake ratio is not necessarily accounted for by increased lactate production from nonoxidative glucose metabolism.

Transcranial Doppler is valid for determination of the lower limit of cerebral blood flow autoregulation

BACKGROUND AND PURPOSE

This study validates transcranial Doppler sonography (TCD) for determination of the lower limit of cerebral blood flow (CBF) autoregulation and establishes a relation between global CBF and mean flow velocity (Vmean) in the middle cerebral artery.

METHODS

Relative changes in CBF and in Vmean were compared in 12 normal volunteers (2 women and 10 men; median age, 30 years [range, 21 to 61 years]). Catheters was placed in the left radial artery and in the bulb of the right internal jugular vein, respectively. Baseline CBF was measured by single-photon emission computed tomography scanning; concomitantly, blood samples were drawn for calculation of the cerebral arteriovenous oxygen difference. Then changes in mean arterial pressure (MAP) were induced, and relative changes in global CBF were calculated according to Fick's principle assuming a constant cerebral oxygen metabolism. MAP was increased 30 mm Hg by norepinephrine infusion and was decreased by lower body negative pressure. Vmean was measured in the right middle cerebral artery by a 2-MHz probe, and blood samples were drawn at intervals of 5 mm Hg.

RESULTS

MAP values between 122 (range, 110 to 140) and 48 (range, 34 to 75) mm Hg were measured. The lower limit of autoregulation (the blood pressure under which autoregulation is off) as determined by Vmean did not differ significantly from that determined by relative changes in global CBF: 91 (range, 41 to 108) and 79 (range, 53 to 113) mm Hg, respectively. A significant correlation between Vmean and relative changes in global CBF was demonstrated below the lower limit of autoregulation (R2 = .73, P < .001; CBF = -6.3 + 1.0.Vmean). Above the lower limit both values were stable.

CONCLUSIONS

TCD is valid for determination of the lower limit of CBF autoregulation, and changes in CBF may be reliably evaluated by TCD during changes in cerebral perfusion pressure in normal subjects.

Plasma phospholipid fatty acid profiles and their association with food intakes: results from a cross-sectional study within the European Prospective Investigation into Cancer and Nutrition

BACKGROUND

Plasma phospholipid fatty acids have been correlated with food intakes in populations with homogeneous dietary patterns. However, few data are available on populations with heterogeneous dietary patterns.

OBJECTIVE

The objective was to investigate whether plasma phospholipid fatty acids are suitable biomarkers of dietary intakes across populations involved in a large European multicenter study.

DESIGN

A cross-sectional study design nested to the European Prospective Investigation into Cancer and Nutrition (EPIC) was conducted to determine plasma fatty acid profiles in >3,000 subjects from 16 centers, who had also completed 24-h dietary recalls and dietary questionnaires. Plasma fatty acids were assessed by capillary gas chromatography. Ecological and individual correlations were calculated between fatty acids and select food groups.

RESULTS

The most important determinant of plasma fatty acids was region, which suggests that the variations across regions are largely due to different food intakes. Strong ecological correlations were observed between fish intake and long-chain n-3 polyunsaturated fatty acids (r = 0.78, P < 0.01), olive oil and oleic acid (r = 0.73, P < 0.01), and margarine and elaidic acid (r = 0.76, P < 0.01). Individual correlations varied across the regions, particularly between olive oil and oleic acid and between alcohol and the saturation index, as an indicator of stearoyl CoA desaturase activity.

CONCLUSIONS

These findings indicate that specific plasma phospholipid fatty acids are suitable biomarkers of some food intakes in the EPIC Study. Moreover, these findings suggest complex interactions between alcohol intake and fatty acid metabolism, which warrants further attention in epidemiologic studies relating dietary fatty acids to alcohol-related cancers and other chronic diseases.

DHA induces ER stress and growth arrest in human colon cancer cells: associations with cholesterol and calcium homeostasis

Polyunsaturated fatty acids (PUFAs) are normal constituents of the diet, but have properties different from other fatty acids (e.g., through generation of signaling molecules). N-3 PUFAs reduce cancer cell growth, but no unified mechanism has been identified. We show that docosahexaenoic acid (DHA; 22:6 n-3) causes extensive changes in gene expression patterns at mRNA level in the colon cancer cell line SW620. Early changes include unfolded protein response (UPR) and increased levels of phosphorylated eIF2α as verified at protein level. The latter is considered a hallmark of endoplasmic reticulum (ER) stress and is abundantly present already after 3 h. It may coordinate many of the downstream changes observed, including signaling pathways for cell cycle arrest/apoptosis, calcium homeostasis, cholesterol metabolism, ubiquitination, and proteasomal degradation. Also, eicosapentaenoic acid (EPA), but not oleic acid (OA), induced key mediators of ER stress and UPR at protein level. Accumulation of esterified cholesterol was not compensated for by increased total levels of cholesterol, and mRNAs for cholesterol biosynthesis as well as de novo synthesis of cholesterol were reduced. These results suggest that cytotoxic effects of DHA are associated with signaling pathways involving lipid metabolism and ER stress.

Prediagnostic circulating vitamin D levels and risk of hepatocellular carcinoma in European populations: a nested case-control study

The association between vitamin D status and hepatocellular carcinoma (HCC) has not been well investigated, despite experimental evidence supporting an important role of vitamin D in liver pathophysiology. Our objective was to investigate the association between prediagnostic circulating 25-hydroxyvitamin D [25(OH)D] serum levels and the risk of HCC in a prospective, nested case-control study among 520,000 participants in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Each case (n = 138) diagnosed between 1992 and 2010 was matched to one control by age, sex, study center, date and time of blood collection, and fasting status. Serum baseline levels of 25(OH)D were measured by liquid chromatography/tandem mass spectrometry. Multivariable incident rate ratios (IRRs) of HCC associated with continuous (per 10 nmol/L) or categorical levels (tertiles or a priori-defined categories) of prediagnostic 25(OH)D were calculated using conditional logistic regression. Higher 25(OH)D levels were associated with a 49% reduction in the risk of HCC (highest versus lowest tertile: multivariable IRR = 0.51, 95% confidence interval [CI], 0.26 to 0.99; Ptrend  = 0.04; per 10 nmol/L increase: IRR = 0.80, 95% CI, 0.68-0.94). The finding did not vary substantially by time from enrolment to diagnosis, and did not change after adjustment for biomarkers of preexisting liver damage, nor chronic infection with hepatitis B or C viruses. The findings were not modified by body size or smoking status.

CONCLUSION

In this prospective study on western European populations, serum levels of 25(OH)D were inversely associated with the risk of HCC. Given the rising incidence of this cancer in low-risk developed countries and the strong public health interest surrounding the potentially cancer-protective roles of vitamin D, additional studies in different populations are required.

GlideScope videolaryngoscope vs. Macintosh direct laryngoscope for intubation of morbidly obese patients: a randomized trial

BACKGROUND

Morbidly obese patients are at increased risk of hypoxemia during tracheal intubation because of increased frequency of difficult and impossible intubation and a decreased apnea tolerance. In this study, intubation with the GlideScope videolaryngoscope (GS) was compared with the Macintosh direct laryngoscope (DL) in a group of morbidly obese patients.

METHODS

One hundred consecutive patients (body mass index ≥ 35 kg/m(2) ) scheduled for bariatric surgery were randomized 1 : 1 to intubation with GS (group GS) or DL (group DL). The primary outcome was intubation time. Secondary outcomes were number of attempts, Cormack-Lehane grade, intubation difficulty scale score (IDS), subjective difficulty of intubation, desaturation, airway bleeding, postoperative sore throat, and hoarseness. Group assignment was not blinded.

RESULTS

Intubation in group GS and group DL lasted 48 (22-148) and 32 s (17-209), respectively (median (range); P = 0.0001); median difference 11 s (95% confidence interval 6-17). Laryngoscopic views were better in group GS with Cormack-Lehane grades 1/2/3/4 distributed as 35/13/2/0 vs. 23/13/10/4 in group DL (P = 0.003). IDS scores were significantly lower with GS than with DL. No other statistically significant differences were found. Two cases of failed intubation occurred in group DL vs. none in group GS (non-significant). Both patients were intubated with the GlideScope without problems.

CONCLUSION

Intubation of morbidly obese patients with GS was slightly slower than with DL. The increased intubation time was of no clinical consequence as no patients became hypoxemic. Both devices generally performed well in the studied population, but the GS provided better laryngoscopic views and decreased IDS scores.

Age dependency of resistance to cerebrospinal fluid outflow

OBJECT

Resistance to cerebrospinal fluid (CSF) outflow (Rout)is an important parameter in assessing the need for CSF shunt placement in patients with hydrocephalus. The normal lower limit of Rout has been estimated on the basis of the clinical effect of shunt placement in patients with varying values of Rout and in young healthy volunteers. The lack of clinical effect from CSF shunts in some elderly patients, despite elevated Rout,suggests that the normal value of Rout increases with age and may be higher in elderly persons. The aim of the present study was to examine the relationship between Rout and age in patients without known CSF dynamic disturbances.

METHOD

Fifty-two patients ranging from 20 to 88 years of age and with no known CSF dynamic disorders were examined. The Rout was measured using a lumbar computerized infusion test. The correlation between Rout and age was analyzed by performing linear regression. The Rout increased significantly with patient age. The Rout in a patient in the eighth decade will be approximately 5 mm Hg/ml/minute higher than in a young patient.

CONCLUSIONS

The present study shows a small but critical increase in Rout with increased patient age. A notable residual variation was present and borderline values of Rout should be regarded and used with caution.

Effect of labetalol on cerebral blood flow, oxygen metabolism and autoregulation in healthy humans

We have studied the effects of labetalol on cerebral blood flow (CBF) and cerebral oxygen metabolism (CMRO2) in eight healthy volunteers. CBF was measured by single photon emission computerized tomography before and during infusion of labetalol. CMRO2 was calculated as CBF x cerebral arteriovenous oxygen content difference (CaO2-CvO2). CBF autoregulation was tested during infusion of labetalol by changing arterial pressure and estimating relative changes in global CBF from changes in (CaO2-CvO2). CBF before and during infusion of labetalol was 67 and 65 ml/100 g min-1, respectively (P > 0.05). CMRO2 was 2.9 and 2.8 ml/100 g min-1, respectively (P > 0.05). CBF autoregulation was preserved in all subjects. The lower limit of CBF autoregulation was 88 mm Hg (94% of baseline mean arterial pressure). We conclude that labetalol did not influence global or regional CBF, or CMRO2, and CBF autoregulation was preserved.

Changes in cerebral blood flow and carbohydrate metabolism during acute hyperketonemia

During starvation, brain energy metabolism in humans changes toward oxidation of ketone bodies. To investigate if this shift is directly coupled to circulating blood concentrations of ketone bodies, we measured global cerebral blood flow (CBF) and global cerebral carbohydrate metabolism with the Kety-Schmidt technique before and during intravenous infusion with ketone bodies. During acute hyperketonemia (mean beta-hydroxybutyrate blood concentration 2.16 mM), cerebral uptake of ketones increased from 1.11 to 5.60 mumol.100 g-1.min-1, counterbalanced by an equivalent reduction of the cerebral glucose metabolism from 25.8 to 17.2 mumol.100 g-1.min-1, with the net result being an unchanged cerebral uptake of carbohydrates. In accordance with this, global cerebral oxygen metabolism was not significantly altered (144 vs. 135 mumol.100 g-1.min-1). The unchanged global cerebral metabolic activity was accompanied by a 39% increase in CBF from 51.0 to 70.9 ml.100 g-1.min-1. Regional analysis of the glucose metabolism by positron emission tomography-[18F]fluoro-2-deoxy-D-glucose indicated that mesencephalon does not oxidize ketone bodies to the same extent as the rest of the brain. It was concluded that the immediate oxidation of ketone bodies induced a decrease in cerebral glucose uptake in spite of an adequate glucose supply to the brain. Furthermore, acute hyperketonemia caused a resetting of the coupling between CBF and metabolism that could not be explained by alterations in arterial CO2 tension or pH.

Validation of transcranial near-infrared spectroscopy for evaluation of cerebral blood flow autoregulation

The aim of the study was to evaluate a new noninvasive transcranial near-infrared spectroscopy (TNIRS) technique for determination of the lower limit of cerebral blood flow (CBF) autoregulation by comparing this technique with the standard cerebral arteriovenous oxygen saturation difference (AVDo2) method. In eight healthy volunteers, mean arterial blood pressure was increased by infusion of angiotensin and decreased by the combination of lower-body negative pressure and labetalol. For each 5-mm Hg change in mean arterial pressure, blood was sampled from the bulb of the internal jugular vein and a radial artery, and simultaneously, the oxygen saturation of hemoglobin in the brain was measured with an INVOS 3100 Cerebral Oximeter (Somanetics). The lower limit of autoregulation was then calculated by a computer using (a) AVDo2 and (b) the difference between arterial oxygen saturation and the saturation determined with the cerebral oximeter (ACDo2). The median lower limit of autoregulation determined by the two methods was 73 and 78.5 mm Hg, respectively (p > 0.05). A statistically significant correlation between relative CBF (percentage of baseline) determined with the two methods was found below the lower limit of autoregulation (1/AVDo2 = 12 + 0.8 x 1/ACDo2; r = 0.55; p < 0.001). For all the 98 pairs of saturations registered, the correlation was 0.37 (p < 0.001), the mean difference was 16%, and the limits of agreement were -2.2 and 33.8%. We conclude that the cerebral oximeter might be useful in evaluation of the lower limit of cerebral autoregulation. This method, however, is of no value for estimation of levels of global cerebral oxygen saturation.

Genome-wide profile of pleural mesothelioma versus parietal and visceral pleura: the emerging gene portrait of the mesothelioma phenotype

BACKGROUND

Malignant pleural mesothelioma is considered an almost incurable tumour with increasing incidence worldwide. It usually develops in the parietal pleura, from mesothelial lining or submesothelial cells, subsequently invading the visceral pleura. Chromosomal and genomic aberrations of mesothelioma are diverse and heterogenous. Genome-wide profiling of mesothelioma versus parietal and visceral normal pleural tissue could thus reveal novel genes and pathways explaining its aggressive phenotype.

METHODOLOGY AND PRINCIPAL FINDINGS

Well-characterised tissue from five mesothelioma patients and normal parietal and visceral pleural samples from six non-cancer patients were profiled by Affymetrix oligoarray of 38 500 genes. The lists of differentially expressed genes tested for overrepresentation in KEGG PATHWAYS (Kyoto Encyclopedia of Genes and Genomes) and GO (gene ontology) terms revealed large differences of expression between visceral and parietal pleura, and both tissues differed from mesothelioma. Cell growth and intrinsic resistance in tumour versus parietal pleura was reflected in highly overexpressed cell cycle, mitosis, replication, DNA repair and anti-apoptosis genes. Several genes of the "salvage pathway" that recycle nucleobases were overexpressed, among them TYMS, encoding thymidylate synthase, the main target of the antifolate drug pemetrexed that is active in mesothelioma. Circadian rhythm genes were expressed in favour of tumour growth. The local invasive, non-metastatic phenotype of mesothelioma, could partly be due to overexpression of the known metastasis suppressors NME1 and NME2. Down-regulation of several tumour suppressor genes could contribute to mesothelioma progression. Genes involved in cell communication were down-regulated, indicating that mesothelioma may shield itself from the immune system. Similarly, in non-cancer parietal versus visceral pleura signal transduction, soluble transporter and adhesion genes were down-regulated. This could represent a genetical platform of the parietal pleura propensity to develop mesothelioma.

CONCLUSIONS

Genome-wide microarray approach using complex human tissue samples revealed novel expression patterns, reflecting some important features of mesothelioma biology that should be further explored.

Command-related distribution of regional cerebral blood flow during attempted handgrip

To localize a central nervous feed-forward mechanism involved in cardiovascular regulation during exercise, brain activation patterns were measured in eight subjects by employing positron emission tomography and oxygen-15-labeled water. Scans were performed at rest and during rhythmic handgrip before and after axillary blockade with bupivacaine. After the blockade, handgrip strength was reduced to 25% (range 0-50%) of control values, whereas handgrip-induced heart rate and blood pressure increases were unaffected (13 +/- 3 beats/min and 12 +/- 5 mmHg, respectively; means +/- SE). Before regional anesthesia, handgrip caused increased activation in the contralateral sensory motor area, the supplementary motor area, and the ipsilateral cerebellum. We found no evidence for changes in the activation pattern due to an interaction between handgrip and regional anesthesia. This was true for both the blocked and unblocked arm. It remains unclear whether the activated areas are responsible for the increase in cardiovascular variables, but neural feedback from the contracting muscles was not necessary for the activation in the mentioned areas during rhythmic handgrip.

Effect of 1 or 2 MAC isoflurane with or without ketanserin on cerebral blood flow autoregulation in man

We have studied the effect of 1 or 2 MAC isoflurane with or without ketanserin on cerebral blood flow (CBF), cerebral oxygen metabolism (CMRO2) and CBF autoregulation in 20 adult patients undergoing lumbar disc surgery. Ten patients received ketanserin and 10 isotonic saline. CBF measurements were started after 1 h of infusion of saline or ketanserin. The patients were anaesthetized with thiopentone 5 mg kg-1 followed by isoflurane. During 1 MAC of isoflurane, baseline values were recorded and then CBF autoregulation was examined (mean arterial pressure increased by about 30% with angiotensin). The sequence was repeated with 2 MAC of isoflurane. CBF was measured by the i.v. xenon-133 technique. CMRO2 was calculated as the product of CBF and the cerebral arterio-venous oxygen content difference. Ketanserin had no effect on CBF, CMRO2 or CBF autoregulation during isoflurane anaesthesia, therefore all patients were pooled for evaluation of the effect of isoflurane. Increasing isoflurane anaesthesia from 1 to 2 MAC increased mean CBF from 41 to 49 ml/100 g min-1 (P < 0.01) and decreased mean CMRO2 from 1.5 to 1.1 ml/100 g min-1 (P < 0.001) and thus abolished the coupling between flow and metabolism. The CBF autoregulation test indicated that autoregulation was disrupted at 2 MAC, but not during 1 MAC isoflurane anaesthesia.

Fish consumption and mortality in the European Prospective Investigation into Cancer and Nutrition cohort

Fish is a source of important nutrients and may play a role in preventing heart diseases and other health outcomes. However, studies of overall mortality and cause-specific mortality related to fish consumption are inconclusive. We examined the rate of overall mortality, as well as mortality from ischaemic heart disease and cancer in relation to the intake of total fish, lean fish, and fatty fish in a large prospective cohort including ten European countries. More than 500,000 men and women completed a dietary questionnaire in 1992-1999 and were followed up for mortality until the end of 2010. 32,587 persons were reported dead since enrolment. Hazard ratios and their 99% confidence interval were estimated using Cox proportional hazard regression models. Fish consumption was examined using quintiles based on reported consumption, using moderate fish consumption (third quintile) as reference, and as continuous variables, using increments of 10 g/day. All analyses were adjusted for possible confounders. No association was seen for fish consumption and overall or cause-specific mortality for both the categorical and the continuous analyses, but there seemed to be a U-shaped trend (p < 0.000) with fatty fish consumption and total mortality and with total fish consumption and cancer mortality (p = 0.046).

Low-frequency hearing loss after spinal anesthesia. Perilymphatic hypotonia?

Audiological tests were conducted on 34 patients before and after undergoing an operation under spinal anesthesia. One of these patients developed a considerable unilateral hearing loss in the low-frequency range, which persisted until an epidural blood-patch was given. Unexpectedly, we also found a general small significant threshold shift at 500 Hz, which has never before been described in the literature. The biological mechanism is discussed and the results suggest that the explanation of the hearing loss could be an endolymphatic hydrops resulting from perilymphatic hypotonia due to loss of liquor, during and after the spinal anesthesia.

Ecological-level associations between highly processed food intakes and plasma phospholipid elaidic acid concentrations: results from a cross-sectional study within the European prospective investigation into cancer and nutrition (EPIC)

Elaidic acid is the main unnatural trans fatty acid isomer occurring during partial hydrogenation of vegetable oils used as ingredients for the formulation of processed foods. The main objective is to assess associations between processed food intakes and plasma phospholipid elaidic acid concentrations within the European Prospective Investigation into Cancer and Nutrition study. A cross-sectional study was used to determine fatty acid profiles in 3,003 subjects from 16 centers. Single 24-h dietary recalls (24-HDR) were collected using a standardized computerized interview program. Food intakes were computed according to their degree of processing (moderately/nonprocessed foods, processed staple foods, highly processed foods). Adjusted ecological and individual correlations were calculated between processed food intakes and plasma elaidic acid levels. At the population level, mean intakes of highly processed foods were strongly correlated with mean levels of plasma elaidic acid in men (P = 0.0016) and in women (P = 0.0012). At the individual level, these associations remained but at a much lower level in men (r = 0.08, P = 0.006) and in women (r = 0.09, P = 0.0001). The use of an averaged 24-HDR measure of highly processed food intakes is adequate for predicting mean levels of plasma elaidic acid among European populations.

Sources of pre-analytical variations in yield of DNA extracted from blood samples: analysis of 50,000 DNA samples in EPIC

The European Prospective Investigation into Cancer and nutrition (EPIC) is a long-term, multi-centric prospective study in Europe investigating the relationships between cancer and nutrition. This study has served as a basis for a number of Genome-Wide Association Studies (GWAS) and other types of genetic analyses. Over a period of 5 years, 52,256 EPIC DNA samples have been extracted using an automated DNA extraction platform. Here we have evaluated the pre-analytical factors affecting DNA yield, including anthropometric, epidemiological and technical factors such as center of subject recruitment, age, gender, body-mass index, disease case or control status, tobacco consumption, number of aliquots of buffy coat used for DNA extraction, extraction machine or procedure, DNA quantification method, degree of haemolysis and variations in the timing of sample processing. We show that the largest significant variations in DNA yield were observed with degree of haemolysis and with center of subject recruitment. Age, gender, body-mass index, cancer case or control status and tobacco consumption also significantly impacted DNA yield. Feedback from laboratories which have analyzed DNA with different SNP genotyping technologies demonstrate that the vast majority of samples (approximately 88%) performed adequately in different types of assays. To our knowledge this study is the largest to date to evaluate the sources of pre-analytical variations in DNA extracted from peripheral leucocytes. The results provide a strong evidence-based rationale for standardized recommendations on blood collection and processing protocols for large-scale genetic studies.

Prediagnostic telomere length and risk of B-cell lymphoma-Results from the EPIC cohort study

Recent epidemiological investigations have reported on the association between telomere length (TL) and a number of malignancies, including B-cell lymphoma (BCL). The reported results for BCLs are however inconsistent. We carried out a nested case-control study to determine whether TL is associated with future risk of BCL. Using quantitative polymerase chain reaction, the relative TL (i.e. the ratio of telomere repeat copy number to single gene copy number) was measured in mononuclear cell DNA of prediagnostic peripheral blood samples of 464 lymphoma cases and 464 matched controls (median time between blood collection and diagnosis, 4.6 years). Conditional logistic regression was used to analyze the association between TL and the risk of developing lymphoma and histologic subtypes. TL was significantly longer in cases compared to controls (p = 0.01). Multivariable models showed a significantly increased risk of BCL [odds ratio (OR) = 1.66, 1.80 and 3.20 for quartiles 2-4, respectively, p-trend = 0.001], diffuse large B-cell lymphoma (DLBCL) (OR = 1.20, 2.48 and 2.36 for quartiles 2-4, respectively, p-trend = 0.03) and follicular lymphoma (FL) (OR = 1.39, 1.90 and 2.69 for quartiles 2-4, respectively, p-trend = 0.02) with increasing TL. This study suggests an association between longer leucocyte TL and increased risk of BCL which was most pronounced for DLBCL and FL.

Dietary intake of trans fatty acids and breast cancer risk in 9 European countries

BACKGROUND

Trans fatty acids (TFAs) have been hypothesised to influence breast cancer risk. However, relatively few prospective studies have examined this relationship, and well-powered analyses according to hormone receptor-defined molecular subtypes, menopausal status, and body size have rarely been conducted.

METHODS

In the European Prospective Investigation into Cancer and Nutrition (EPIC), we investigated the associations between dietary intakes of TFAs (industrial trans fatty acids [ITFAs] and ruminant trans fatty acids [RTFAs]) and breast cancer risk among 318,607 women. Multivariable hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models, adjusted for other breast cancer risk factors.

RESULTS

After a median follow-up of 8.1 years, 13,241 breast cancer cases occurred. In the multivariable-adjusted model, higher total ITFA intake was associated with elevated breast cancer risk (HR for highest vs lowest quintile, 1.14, 95% CI 1.06-1.23; P trend = 0.001). A similar positive association was found between intake of elaidic acid, the predominant ITFA, and breast cancer risk (HR for highest vs lowest quintile, 1.14, 95% CI 1.06-1.23; P trend = 0.001). Intake of total RTFAs was also associated with higher breast cancer risk (HR for highest vs lowest quintile, 1.09, 95% CI 1.01-1.17; P trend = 0.015). For individual RTFAs, we found positive associations with breast cancer risk for dietary intakes of two strongly correlated fatty acids (Spearman correlation r = 0.77), conjugated linoleic acid (HR for highest vs lowest quintile, 1.11, 95% CI 1.03-1.20; P trend = 0.001) and palmitelaidic acid (HR for highest vs lowest quintile, 1.08, 95% CI 1.01-1.16; P trend = 0.028). Similar associations were found for total ITFAs and RTFAs with breast cancer risk according to menopausal status, body mass index, and breast cancer subtypes.

CONCLUSIONS

These results support the hypothesis that higher dietary intakes of ITFAs, in particular elaidic acid, are associated with elevated breast cancer risk. Due to the high correlation between conjugated linoleic acid and palmitelaidic acid, we were unable to disentangle the positive associations found for these fatty acids with breast cancer risk. Further mechanistic studies are needed to identify biological pathways that may underlie these associations.

Fetal death following labetalol administration in pre-eclampsia

Labetalol (Trandate) 50 mg i.v. was administered to a pre-eclamptic primigravida with an asphytic fetus prior to cesarean section, in order to reduce the risk of excessive increase in blood pressure during induction of anesthesia. Blood pressure fell rapidly from 170/110 to 115/85 mmHg. A dead infant was born. Oral labetalol is arguably a suitable remedy for pre-eclampsia, but if i.v. administration is necessary, an initial dose of 5-10 mg is recommended.

Scrutinizing incident reporting in anaesthesia: why is an incident perceived as critical?

BACKGROUND

The purpose of the present study was to measure the incidence and type of incidents that occurred in relation to anaesthesia and surgery during a 1-year period in six Danish hospitals. Furthermore, we wanted to identify risk factors for incidents, as well as risk factors for incidents being deemed critical.

METHODS

A four-page questionnaire describing patient data, type of anaesthesia and surgery, and occurrence of incidents was filled in for all anaesthesias in the period, and subsequently processed. The incident reporting form incorporated 59 predefined adverse events. The occurrence of one or more of these events described the incident. When the reporting anaesthetist deemed that an incident had harmed the patient, that incident was defined as critical.

RESULTS

A total of 64,312 anaesthesias were reported, and in 7754 of them one or more incidents occurred. A total of 8510 incidents occurred, 4077 of them were solely related to the anaesthetic procedure, 3702 described events related to physiological alterations in the patient (physiological incidents). Three hundred and twenty-three of the incidents were deemed critical. High ASA score, high age, abdominal surgery, urgent surgery, and complex anaesthetic procedure were significant risk factors for physiological incidents and critical incidents. We could not identify a simple subset of adverse events that could adequately be used to describe the critical incidents. However, complex incidents, i.e. incidents involving more than one adverse event, were more likely to be deemed critical than simple incidents.

CONCLUSION

The incidence of incidents was 12.1%, and the incidence of critical incidents was 0.5%. Incidents were more likely to be deemed critical in patients with an ASA score of III and above undergoing urgent surgery.

Nutrient-wide association study of 92 foods and nutrients and breast cancer risk

BACKGROUND

Several dietary factors have been reported to be associated with risk of breast cancer, but to date, unequivocal evidence only exists for alcohol consumption. We sought to systematically assess the association between intake of 92 foods and nutrients and breast cancer risk using a nutrient-wide association study.

METHODS

Using data from 272,098 women participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) study, we assessed dietary intake of 92 foods and nutrients estimated by dietary questionnaires. Cox regression was used to quantify the association between each food/nutrient and risk of breast cancer. A false discovery rate (FDR) of 0.05 was used to select the set of foods and nutrients to be replicated in the independent Netherlands Cohort Study (NLCS).

RESULTS

Six foods and nutrients were identified as associated with risk of breast cancer in the EPIC study (10,979 cases). Higher intake of alcohol overall was associated with a higher risk of breast cancer (hazard ratio (HR) for a 1 SD increment in intake = 1.05, 95% CI 1.03-1.07), as was beer/cider intake and wine intake (HRs per 1 SD increment = 1.05, 95% CI 1.03-1.06 and 1.04, 95% CI 1.02-1.06, respectively), whereas higher intakes of fibre, apple/pear, and carbohydrates were associated with a lower risk of breast cancer (HRs per 1 SD increment = 0.96, 95% CI 0.94-0.98; 0.96, 95% CI 0.94-0.99; and 0.96, 95% CI 0.95-0.98, respectively). When evaluated in the NLCS (2368 cases), estimates for each of these foods and nutrients were similar in magnitude and direction, with the exception of beer/cider intake, which was not associated with risk in the NLCS.

CONCLUSIONS

Our findings confirm a positive association of alcohol consumption and suggest an inverse association of dietary fibre and possibly fruit intake with breast cancer risk.

Prevention of hypotension during spinal anaesthesia for caesarean section

Twenty-six parturients scheduled to receive spinal anaesthesia for caesarean section were randomized to receive either isotonic saline 750 ml plus 20 ml/kg (group A) or 750 ml plus 500 ml (group B) before subarachnoid administration of bupivacaine 13 mg. Ephedrine 0.15 mg/kg i.v. followed by an infusion 0.4 mg.kg(-1) h(-1) were then administered in group B. In both groups ephedrine 10 mg/min i.v. was given if the mean arterial blood pressure decreased more than 10 mmHg. Despite the fluid preload and large doses of ephedrine noted {median (range), group A 30 mg (10-80), group B 92 mg (25-194)}, hypotension, sometimes accompanied by nausea, still occurred. Mean maternal arterial was significantly lower in group A than in group B 5-10 min after induction of spinal anaesthesia (P < 0.05). There was no difference in the frequency of nausea or vomiting, Apgar score, or pH in umbilical cord blood. One neonate in group A and 2 in group B were acidotic. In conclusion, a reduced volume loading could be compensated with an increased ephedrine administration after induction of spinal anaesthesia, without increasing the incidence of hypotension or other maternal or neonatal complications. However, the fluid volumes and/or ephedrine doses used were not sufficient to prevent hypotension altogether.

Circulating inflammatory biomarkers, adipokines and breast cancer risk-a case-control study nested within the EPIC cohort

BACKGROUND

Inflammation has been hypothesized to play a role in the development and progression of breast cancer and might differently impact breast cancer risk among pre and postmenopausal women. We performed a nested case-control study to examine whether pre-diagnostic circulating concentrations of adiponectin, leptin, c-reactive protein (CRP), tumour necrosis factor-α, interferon-γ and 6 interleukins were associated with breast cancer risk, overall and by menopausal status.

METHODS

Pre-diagnostic levels of inflammatory biomarkers were measured in plasma from 1558 case-control pairs from the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. We used conditional logistic regression to estimate the odds ratios (ORs) of breast cancer at blood collection, per one standard deviation increase in biomarker concentration.

RESULTS

Cases were diagnosed at a mean age of 61.4 years on average 8.6 years after blood collection. No statistically significant association was observed between inflammatory markers and breast cancer risk overall. In premenopausal women, borderline significant inverse associations were observed for leptin, leptin-to-adiponectin ratio and CRP [OR= 0.89 (0.77-1.03), OR= 0.88 (0.76-1.01) and OR= 0.87 (0.75-1.01), respectively] while positive associations were observed among postmenopausal women [OR= 1.16 (1.05-1.29), OR= 1.11 (1.01-1.23), OR= 1.10 (0.99-1.22), respectively]. Adjustment for BMI strengthened the estimates in premenopausal women [leptin: OR = 0.83 (0.68-1.00), leptin-to-adiponectin ratio: OR = 0.80 (0.66-0.97), CRP: OR = 0.85 (0.72-1.00)] but attenuated the estimates in postmenopausal women [leptin: OR = 1.09 (0.96-1.24), leptin-to-adiponectin ratio: OR = 1.02 (0.89-1.16), CRP: OR = 1.04 (0.92-1.16)].

CONCLUSIONS

Associations between CRP, leptin and leptin-to-adiponectin ratio with breast cancer risk may represent the dual effect of obesity by menopausal status although this deserves further investigation.