Alcohol discovered in the urine after death: ante-mortem ingestion or post-mortem artefact?

A study was undertaken of blood and urine alcohol levels in 44 cases where the bodies had been immersed in water, following accidents, for at least one day after death. In no case was there any ante-mortem evidence of ingested alcohol. In 15 cases there was a raised urine alcohol. The average urine-to-blood alcohol ratio in these cases was 0.56:1. This is dramatically less that that seen after ingestion. It is suggested that the alcohol, following its initial post-mortem production in the abdomen, enters the urine by diffusion from surrounding tissues. The presence of alcohol in the urine from bodies that have not been recovered and examined until several days after death cannot always be taken to indicate ante-mortem ingestion. Urine-to-blood alcohol ratios of less than 1:1 are strongly suggestive of post-mortem production.     

The relationship between blood and urine alcohol concentrations at autopsy

The relationship between the blood alcohol concentration and the urine alcohol concentration was studied in 109 routine coroner's autopsies. Although the average ratio for urine alcohol concentration to blood alcohol concentration lay close to the ratio of 4:3 quoted in the literature, the actual ratios determined were widely scattered around this value. Thus the use of this simple ratio to estimate the blood alcohol concentration from the urine alcohol concentration at post-mortem was unreliable. An equation determined by employing linear regression analysis was similarly unhelpful in enabling one to derive a precise value for the blood alcohol concentration from a given urine alcohol concentration. It was concluded that the main value in determining the urine alcohol concentration at autopsy was to exclude the possibility of the alcohol present in the blood sample having been generated during the post-mortem interval.     

Steroid profile analysis and UGT2B17 genotyping of the same urine sample to determine testosterone abuse

When testing a urine sample for testosterone abuse, a ratio of testosterone glucuronide (T) to epitestosterone glucuronide (ET) of 4.0 or above is considered suspicious. A degree of variation, however, has been observed in T/ET ratio between individuals from both the same and different ethnic backgrounds. The majority of this variation might be due to UGT2B17 deletion genotype (UGT2B17 deletion-type). The aim of this study was to investigate the use of the same urine sample for the analysis of T/ET ratio and UGT2B17 deletion-type. Japanese men were deletion-typed via a UGT2B17 copy number assay using DNA from blood. Urinary T and ET levels were determined using gas chromatography–mass spectrometry before (n = 112) and after a testosterone injection (n = 25). Basal T level and the increase in T/ET ratio after injection were dependent on UGT2B17 deletion-type, being lower in subjects with deletion (del/del) than nondeletion (ins/del or ins/ins) genotype. UGT2B17 deletion-typing was first performed using DNA from urine cryopreserved for 1–1.5 years (n = 66). The concentration of DNA required for discrimination between the deletion and nondeletion genotype by copy number assay was more than 0.1 ng/ml urine. Discrimination was possible in 94.0 % of urine samples (5–7 ml each). These findings show that T/ET ratio and UGT 2B17 deletion-type can be analyzed exclusively via urine samples, removing the need for the collection of other samples, such as blood or buccal cells. The combination of T/ET ratio and UGT 2B17 deletion-type may help inform decisions regarding a genotype-specific T/ET cutoff ratio.     

Correlation between postmortem ethanol levels in the blood and the testicle

Summary This study emphasizes the value of the presence of ethanol in the testicle. It proves particularly useful in cases where blood and urine are no more present in the body.In 633 cases where blood or urine were still available, a highly positive correlation between the blood alcohol and the amount of alcohol present in the testicle could be demonstrated, thus confirming the research carried out in the Department of Legal Medicine as far back as 1943.An attempt is further made to assess the possible influence of such factors as putrefaction, submersion or post-traumatic anemia on this correlation.Presented at the 9th Meeting of the International Association of Forensic Sciences, Bergen/Norway, June 1981     

Practical use of ethyl glucuronide and ethyl sulfate in postmortem cases as markers of antemortem alcohol ingestion

In postmortem toxicology, it could be difficult to determine whether a positive blood ethanol concentration reflects antemortem ingestion or postmortem synthesis of alcohol. Measurement of the nonoxidative ethanol metabolite ethyl glucuronide (EtG) has been suggested as a marker of antemortem ingestion of alcohol, but EtG might degrade postmortem which could make interpretation difficult. So far, the published articles concern EtG only. Another nonoxidative metabolite, ethyl sulfate (EtS), which is more stable, has therefore been included in this study. We present a material of 36 deaths where postmortem formation of ethanol was suspected and where both EtG and EtS were measured in blood and urine to assist the interpretation. In 19 cases, EtG and EtS were positive in the body fluids analyzed. The median concentration of EtG and EtS in blood was 0.4 (range 0.1–23.2) and 0.9 mg/L (range 0.04–7.9), respectively. The median concentration of EtG and EtS in urine was 35.9 (range 1.0–182) and 8.5 mg/L (range 0.3–99), respectively. In another 16 cases, there was no trace of EtG or EtS in the specimens analyzed. In one case, there was inconsistency between the results of EtG and EtS; they were both positive in urine, while only EtS was positive in blood. This study showed that, out of 36 cases, antemortem ingestion of alcohol was very likely in 19 and unlikely in 16, according to EtG and EtS results. In the last case, the interpretation was more difficult. One possible explanation would be postmortem degradation of EtG in blood.     

瑞舒伐他汀钙联合步长脑心通降脂的疗效和安全性研究

目的评价瑞舒伐他汀钙和步长脑心通联合降脂的疗效和安全性,以及对低密度脂蛋白与高密度脂蛋白比值(LDL-C/HDL-C)和脂蛋白a[Lp(a)]的干预效果。方法采用随机平行组间对照研究的方法,将筛选合格的136例受试者随机分配为A组68例、B组68例,B组给瑞舒伐他汀钙10 mg,1次/d,A组在B组基础上给步长脑心通4粒,3次/d,连续治疗12周。分别于受试后的第4、8、12周随访。结果两组患者在治疗第4、8、12周后血脂水平均有显著下降(P<0.05),联合治疗效果均优于单用组。两组治疗4周时血脂水平均有下降,但两组差异无统计学意义。治疗8周时,联合治疗组血脂明显下降,且效果优于单用组,差异有统计学意义(P<0.05),治疗12周时,联合治疗组血脂水平下降显著,LDL-C/HDL-C和Lp(a)的水平下降更显著,差异有显著统计学意义(P<0.01)。结论瑞舒伐他汀钙联合步长脑心通可显著降低血脂水平,可显著降低LDL-C/HDL-C和Lp(a)的水平,且有良好安全性。     

Evaluating alleged drinking after driving--the hip-flask defence. Part 1. Double blood samples and urine-to-blood alcohol relationship

This two-part article examines the strengths and weaknesses of various ways of investigating claims of drinking alcohol after driving, commonly known as the hip-flask or glove-compartment defence. In many countries the onus of proof in hip-flask cases rests on the prosecution. With good co-operation from the police and timely sampling of body fluids, such as blood and urine for forensic analysis of ethanol, useful evidence can be mustered to support or challenge the truthfulness of alleged drinking after driving. The person's blood-alcohol concentration (BAC) can be compared with values expected on the basis of the amount of alcohol consumed after driving, according to theoretical Widmark calculations. The actual BAC measured is then adjusted for the additional amount of alcohol consumed in the after-drink. Double blood samples, that is, taking two specimens of venous blood about 30-60 minutes apart and looking at the magnitude and direction of change in BAC provides little or no more information than a single blood specimen. However, the relationship between alcohol in blood and urine is very useful in hip-flask cases whereby the concentration expected in the primary urine is compared with the concentration in the bladder urine voided. The concentration of alcohol determined in a second urine sample collected 30-60 min later gives supporting evidence in hip-flask cases. A graphical method, which entails plotting ethanol concentrations in blood and urine as a function of time provides a robust and practical way to investigate hip-flask defences. In the second part of the review, congener analysis is presented, which entails comparing the concentrations of n-propanol, isobutanol and occasionally other congeners in the alcoholic beverage allegedly consumed after driving with the volatiles present in the suspect's blood and urine determined by headspace gas chromatography.     

Graphical analysis and simplified quantification of striatal and extrastriatal dopamine D2 receptor binding with [123I]epidepride SPECT.

The purpose of this study was to extend the graphical analysis of reversible tracer binding to account for labeled lipophilic metabolites (metabolites) in quantifying [123I]epidepride binding to striatal and extrastriatal D2 receptors and, additionally, to evaluate the feasibility of simplified analysis to measure the specific volume of distribution (V3') using single-sample blood data because the tissue ratio (RT) may be a less reliable measure of D2 binding in the presence of metabolites. METHODS: Multilinear regression analysis (MLRA) and graphical analysis (GA) using plasma parent (P) plus metabolite (M) activities as input and time activities of receptor-free (RF, cerebellum) and receptor-containing regions (RR, striatum and temporal cortex) derived V3' = (alpha(RR)(P) - alpha(RF)(P)), V3' = (1 + delta) (alpha(RR) - alpha(RF)) and RT = V3'/(V2P' + deltaV2M'), where alpha is a regression coefficient, delta is the equilibrium area ratio of M and P, and (V2P'/V2M') are the corresponding nondisplaceable distribution volumes. V3' by simplified analysis (SA) was calculated from RT determined without blood data and (V2P' + deltaV2M') with single-blood sample data. The accuracy of these three V3' values was assessed relative to the metabolite-accounted kinetic analysis (KA) for [123I]epidepride SPECT studies of 11 healthy volunteers, in which each participant had 27 scans and 30 plasma samples drawn during the 14 h after injection. RESULTS: All three V3' values (mL/g) significantly correlated with those by KA (r > or = 0.90) (striatum/temporal cortex: MLRA, 77.8 +/- 36.6/2.35 +/- 1.16; GA, 98.8 +/- 34.2/4.61 +/- 1.77; SA, 83.9 +/- 24.8/4.26 +/- 1.74; KA, 107.6 +/- 34.4/5.61 +/- 1.84). However, the correlation between RT and V3' was only moderate (r < or = 0.65) because of significant intersubject variability (23%) in (V2P' + deltaV2M'). CONCLUSION: The graphical analysis can be extended to account for metabolites in measuring D2 binding with [123I]epidepride SPECT for both high and low D2 density regions. Additionally, simplified V3' measurements with single blood sampling are feasible and may be a practical alternative to the tissue ratio RT because RT suffers as a measure of D2 binding from significant intersubject variability in the metabolite-contributed distribution volume of the nondisplaceable compartment.     

电烧伤患者血清肌酸磷酸激酶变化与电烧伤肌肉坏死感染的关系

目的：探讨血清肌酸磷酸激酶(craetine phos phokinase，CK)及其同工酶(CK—MM)的变化对电烧伤患者肌肉感染、坏死的诊断价值。方法：高压电击伤与电弧烧伤各40例，分为A、B两组，A组为手术证实有明显的肌肉坏死者，B组为手术证实无肌肉坏死者。分别监测患者伤后、术前及术后血清CK—MM的浓度，同期进行血、尿常规，肝、肾功能检查，并以30例正常人血清CK—MM值作为对照。结果：(1)A组伤后及扩创术后1天血清CK—MM的浓度显著升高，达正常对照组的5倍；术后3天降至正常，其变化与手术所见、外周血白细胞计数变化相一致；(2)B组植皮术前及术后CK-MM值轻度升高。结论：CK-MM可作为电击伤肌肉感染坏死的监测指标，具有较高的特异性和敏感性。     

A study of blood and urine alcohol concentrations in cases of alleged drug-facilitated sexual assault in the United Kingdom over a 3-year period

This paper details the alcohol concentrations found in a selection of 1,014 cases of claimed drug-facilitated sexual assault analysed at The Forensic Science Service, London Laboratory between January 2000 and December 2002. Where appropriate, either a whole blood sample and/or a urine sample was analysed for alcohol, common drugs of abuse and potentially stupefying drugs. The samples were collected from a complainant within 12 h of an alleged incident in 391 of the 1014 cases analysed. Of these, the majority (81%) contained alcohol. The presence of alcohol itself was not surprising as most of the alleged incidents were associated with social situations such as at a public house, bar, night-club or party, where it is expected that alcohol would have been consumed. However, 233 (60%) of the 391 cases had a high back-calculated figure, where high is defined as greater than 150 milligrams per 100 millilitres (150 mg%). Some of these samples were also found to contain illicit drugs. This is the first paper to our knowledge which discusses in detail the significance of the alcohol concentrations found in cases of this type.     

Simple quantification of skeletal muscle glucose utilization by static 18F-FDG PET.

Skeletal muscle glucose utilization (SMGU) can be measured by dynamic PET imaging with (18)F-FDG to characterize insulin resistance. The aim of this study was to determine the validity of simple methods to quantify SMGU by static PET imaging. METHODS: Ten patients underwent dynamic (18)F-FDG PET of the femoral region during hyperinsulinemic euglycemic clamping. SMGU was determined by Patlak graphical analysis using data from dynamic imaging with frequent arterial blood sampling. Standardized uptake values (SUVs) were calculated at 45 and 55 min after tracer injection. Skeletal muscle-to-background ratio (SM/B ratio), tissue count divided by venous plasma activity, was also computed at 45 and 55 min. These simple indices were compared by linear regression with the SMGU measured as above, and an estimated SMGU was obtained using the regression equation thus generated, together with a simple index. RESULTS: SMGU was highly correlated with SUVs (r = 0.941 at 45 min, r = 0.951 at 55 min) and SM/B ratios (r = 0.968 at 45 min, r = 0.984 at 55 min). Although SMGU was almost proportional to SM/B ratios, the y-intercepts of the regression lines for SUVs significantly differed from zero. The residual in estimating SMGU using the regression equation was marginally smaller for SM/B ratios than for SUVs and for indices at 55 min than at 45 min, but these differences did not reach statistical significance. Correction for plasma glucose level slightly elevated the correlation coefficients between SMGU and these simple indices. CONCLUSION: It is proposed that the simple quantitative indices, SUV and the SM/B ratio, are reliable indicators of SMGU during hyperinsulinemic euglycemic clamping. Static imaging with or without a single venous blood sampling may therefore be able to replace dynamic imaging with frequent arterial blood sampling, offering substantially greater convenience in evaluating insulin resistance.     

Blood, urine and vitreous isopropyl alcohol as biochemical markers in forensic investigations

Isopropyl alcohol (IPA) is widely used as an industrial solvent and cleaning fluid. After ingestion or absorption, IPA is converted into acetone by alcohol dehydrogenase. However, in ketosis, acetone can be reduced to IPA. The aim of this study was to investigate blood IPA and acetone concentrations in a series of 400 medico-legal autopsies, including cases of diabetic ketoacidosis, hypothermia and alcohol misuse-related deaths, to illustrate the extent of ketosis at the time of death. Vitreous glucose, blood 3-β-hydroxybutyrate (3HB) and acetoacetate (AcAc) concentrations were also determined systematically. Additionally, vitreous and urine IPA, acetone, 3HB and AcAc concentrations as well as other biochemical markers, including glycated hemoglobin and carbohydrate-deficient transferrin (CDT) were also determined in selected cases. The results of this study indicate that ketosis is characterized by the presence of IPA resulting from the acetone metabolism and that IPA can be detected in several substrates. These findings confirm the importance of the systematic determination of IPA and acetone levels that is used to quantify biochemical disturbances and the importance of ketosis at the time of death.     

A bacterial signature-based method for the identification of seven forensically relevant human body fluids

Detection and identification of body fluids plays a crucial role in criminal investigation, as it provides information on the source of the DNA as well as corroborative evidence regarding the crime committed, scene, and/or association with persons of interest. Historically, forensic serological methods have been chemical, immunological, catalytic, spectroscopic, and/or microscopic in nature. However, most of these methods are presumptive, with few robust confirmatory exceptions. In recent years several new molecular methods (mRNA, miRNA, DNA methylation, etc.) have been proposed; although promising, these methods require high quality human DNA or RNA. Additional steps are required in RNA based methods. Additionally, RNA based methods cannot be used for old cases where only DNA extracts remain to sample from. In this study, a novel non-human DNA (microbiome) based method was developed for the identification of the majority of forensically relevant human biological samples. Eight hundred and twelve (n = 812) biological samples (semen, vaginal fluid, menstrual blood, saliva, feces, urine, and blood) were collected and preserved using methods commonly used in forensic laboratories for evidence collection. Variable region four (V4) of 16 S ribosomal DNA (16 S rDNA) was amplified using a dual-indexing strategy and then sequenced on the MiSeq FGx sequencing platform using the MiSeq Reagent Kit v2 (500 cycles) and following the manufacturer’s protocol. Machine learning prediction models were used to assess the classification accuracy of the newly developed method. As there was no significant difference in bacterial communities between vaginal fluid, menstrual blood, and female urine, these were combined as female intimate samples. Except in urine, the bacterial structures associated with male and female body fluid samples were not significantly different from one another. The newly developed method accurately identified human body fluid samples with an overall accuracy of more than 88%. This newly developed bacterial signature-based method is fast (no additional steps are needed as the same DNA can be used for both body fluid identification and STR typing), efficient (consume less sample as a single test can identify all major body fluids), sensitive (needs only 5 pg of bacterial DNA), accurate, and can be easily added into a forensic high throughput sequencing (HTS) panel.     

Trace analysis of platinum in blood and urine by ESI-MS-MS

A simple, rapid, and sensitive method has been developed for determination of platinum (Pt) in blood and urine by tandem mass spectrometry (MS-MS). Pt⁴⁺ in wet-ashed blood or acid-treated urine was complexed with diethyldithiocarbamate (DDC), extracted with isoamyl alcohol, and acidified with oxalic acid; a 1-μl aliquot of the isoamyl alcohol layer containing the Pt-DDC complex was directly injected into the MS-MS instrument without chromatographic separation. The quantitation was performed using selected reaction monitoring at m/z 491 of the product ion Pt(DDC)₂⁺, which was produced by collision-induced dissociation from the precursor ion Pt(DDC)₃⁺ at m/z 639. This method was validated for the analysis of blood and urine samples; the limits of quantitation were about 0.3 and 0.1 ng/ml for blood and urine, respectively, using only 10 μl of sample. The calibration curves for Pt in urine and blood showed linearity from 0.1 to 30 ng/ml. Because chromatographic separation is not required before MS-MS detection, the analysis can be completed in less than 10 min.     

Conventional measurements of GFR using <Superscript>51</Superscript>Cr-EDTA overestimate true renal clearance by 10 percent

It is widely believed that measurement of the area under the plasma clearance curve (AUC) following a single intravenous injection of chromium-51 labelled ethylene diamine tetra-acetic acid ((51)Cr-EDTA) is a gold standard method for determining glomerular filtration rate (GFR). However, there are reports that (51)Cr-EDTA may have a significant extrarenal clearance. The aim of this study was to identify the non-renal component of (51)Cr-EDTA plasma clearance contributing to the AUC measurement of GFR. Seventy healthy postmenopausal women (mean age 60 years, range 45-79 years) were injected with 3 MBq (51)Cr-EDTA and 0.25 MBq iodine-125 labelled human serum albumin and 11 blood samples taken between 0 and 4 h through an indwelling venous cannula. For the first 21 subjects, two complete urine collections were made 0-2 h and 2-4 h after injection, and for the final 49 patients, four 1-h urine collections were made. The mean (51)Cr-EDTA total plasma clearance was 84 ml/min (range 50-132 ml/min). The mean ratio (SEM) of urine to total clearance determined from the cumulative 1-, 2-, 3- and 4-h data was 0.903 (0.018), 0.891 (0.013), 0.898 (0.011) and 0.899 (0.010) respectively and remained constant despite the mean urine concentration decreasing from 122% to 15%/litre during this period. A least squares fit to data from the 238 individual urine collections was used to determine the fraction of the total plasma clearance attributable to renal clearance, alpha(0), and the residual urine volume, delta V. The results were alpha(0)=0.910 (95% CI: 0.889-0.932) and delta V=14 ml (95% CI: -4 to +34 ml). The overestimation of the true renal clearance of (51)Cr-EDTA by the AUC method is believed to be due to the failure of the plasma clearance curve to reach the true terminal exponential by 2 h after injection as usually assumed. As a result, conventional measurements of GFR using (51)Cr-EDTA overestimate the true renal clearance of tracer by approximately 10%.     

白芨在经肝动脉化疗栓塞术治疗大鼠肝细胞癌实验中的应用

目的评价白芨在经肝动脉化疗栓塞术(transarterialchemoembolization,TACE)治疗ACI大鼠肝细胞癌实验中的应用价值。方法在30只ACI大鼠肝包膜下植入MorrisHepatom3924A肝癌瘤块(2mm3),移植术后13d进行MR检查,测量肿瘤体积(V1),第14天时,经大鼠胃十二指肠动脉逆行插管至肝动脉,采取以下治疗方案A组01mg丝裂霉素+01ml碘油+10mg白芨(10只);B组01mg丝裂霉素+01ml碘油+10mg白芨+肝动脉结扎(10只);C组01mg丝裂霉素+01ml碘油(对照组,10只)。13d后再次进行MR检查以测量肿瘤体积(V2),比较肝肿瘤体积生长率(V2/V1)。结果介入治疗后与治疗前肿瘤体积之比(V2/V1)分别为A组628,B组153,C组914。与对照组C相比,采取A、B组的治疗方案均能抑制肝肿瘤的生长(P<005和P<001),A组与B组之间的肿瘤生长率差异亦有统计学意义(P<001)。结论白芨作为肝动脉栓塞剂,结合局部化疗术和肝动脉结扎术能明显抑制大鼠肝细胞癌的生长。     

全身照射后肠黏膜通透性与肠三叶因子mRNA表达的关系

目的 探讨全身照射(TBI)对肠道黏膜通透性和肠三叶因子(ITF)mRNA表达的影响以及二者之间的关系.方法 32只BALB/c小鼠随机均分为4组:空白对照组和总剂量8.0 Gy全身照射后4、8和12 d组.TBI剂量8.0 Gy,剂量率1.0 Gy/min.高效液相色谱-蒸发光散射检测器分析(HPLC-ELSD)检测尿液标本中乳果糖与甘露醇的排出率比值(L/M),评价各组小鼠的肠道通透性;收集空肠组织标本,实时荧光定量PCR检测肠道ITF mRNA表达水平.结果 TBI后4、8和12d组L/M比值分别为0.5092±0.0353,0.7174±0.0116和0.7295±0.0063,均明显高于空白对照组(0.2908±0.0533,F=321.47,P＜0.05).TBI后4、8和12 d组ITF mRNA表达水平分别为0.78612±0.1428,0.2521±0.1223,和0.2306±0.0221,均显著低于空白对照组(1.3498±0.0476,F=235.71,P＜0.05).各TBI组中L/M与肠道ITF mRNA水平呈显著负相关(r=-0.985,P＜0.01).结论 TBI后随着时间延长ITF mRNA表达逐渐下降而肠黏膜通透性逐渐增加,即TBI后ITF mRNA表达与肠道通透性呈显著负相关.ITF在TBI所致肠道黏膜通透性增加中起着保护作用.

Abstract：

Objective To investigate the change of the intestinal permeability,the expression level of intestinal trefoil factor (ITF) mRNA and the relationship between them after total body irradiation (TBI),and explore the effect of TBI on the development of intestinal permeability and the expression level of ITF mRNA.Methods Twenty two BALB/c mice were randomly divided into 4 equal groups: 3 groups at 4,8 and 12 d after TBI with the total dose of 8.0 Gy and the dose rate of 1.0 Gy/min respectively,and a control group.Lactulose (L) and mannitol (M) were perfused into the esophagus before the experiment and urine samples were collected.Liquid chromatography was used to measure the L/M excretion ratio in the urine samples collected 4,8,and 12 days after the TBI.And then the mice were killed with their intestine were taken out.The expression of ITF mRNA in the jejunum tissue was detected by real-time fluorescence quantitative PCR.Results The urine L/M ratio levels of the groups 4,8 and 12 days after TBI were (0.5092 ± 0.0352),(0.7174 ± 0.0116),and (0.7295 ± 0.0533) respectively,all significantly higher than that of the control group [(0.2908 ± 0.0533),F = 321.47,P ＜ 0.05].The ITF mRNA expression levels of groups 4,8 and 12 days after TBI were (0.78612 ±0.1428),(0.2521 ±0.1223),and (0.2306 + 0.0221 ) respectively,all significantly lower than that of the control group [( 1.3498 + 0.0476),F = 235.71 ,P ＜ 0.05].The urine L/M ratio was significantly negatively correlated with the expression of ITF mRNA in all TBI groups (r = - 0.985,P ＜ 0.01 ).Conclusions The intestinal permeability increases and the expression level of ITF mRNA decreases after TBI.The urine L/M ratio is negatively correlated with the expression level of ITF mRNA after TBI.ITF is involved in protection against intestinal permeability induced by TBI.     

A comparison of the indirect estimate of mean arterial pressure calculated by the conventional equation and calculated to compensate for a change in heart rate

The standard equation used to calculate mean arterial pressure (MAP) assumes that diastole persists for 2/3 and systole for 1/3 of each cardiac cycle. This ratio is altered when heart rate increases, and therefore we investigated the efficacy of predicting MAP during exercise using non-invasive indirect methods. Eight subjects exercised on a cycle ergometer for 3 minute intervals to elicit heart rates between 100-110, 120-130, 140-150, 160-170, and 180-190 beats/min. In the last minute of each 3 min interval an ECG recording was taken and systolic (SP) and diastolic (DP) blood pressure was measured by manual auscultation. MAP was calculated for each heart rate interval by: MAP=DP+1/3(SP-DP) (method A), and MAP= DP + Fs(SP- DP) (method B), where Fs is the fraction of the cardiac cycle comprising systole, measured from the ECG. Fs increased from 0.35+/-0.049 at rest to 0.47+/-0.039 at a heart rate of 180-190 beats/min. MAP measured by method B was consistently greater than MAP calculated by method A at all heart rates greater than resting heart rate (p<0.01). The error incurred when using the standard MAP equation (method A) to derive MAP during exercise (measured as the percentage difference between method A and B) increased linearly with heart rate (r=0.98). The standard MAP equation should not be applied during exercise, as it does not account for the change in the systolic: diastolic period ratio as heart rate increases.     

颈动脉粥样硬化与冠心病关系的研究

目的　探讨颈动脉粥样硬化与冠心病之间的关系。方法　采用高频超声对 72例因急性心肌梗死、心绞痛及胸痛待查而入院接受冠状动脉造影的病人进行颈动脉检查 ,根据冠状动脉造影结果分为正常冠状动脉组(A组 )和冠状动脉病变组 (分别为单支病变组B1、双支病变组B2、三支病变组B3) ,采用高频超声探测双侧颈总动脉、颈内动脉及颈外动脉 ,计算颈动脉斑块积分 ,测量血管后壁内中膜厚度 (IMT)及颈动脉内血流频谱Vmax。结果　冠状动脉病变组的IMT值明显高于冠状动脉正常组 (P <0 0 5 ) ,冠状动脉三支病变组的IMT值高于单支和双支病变组 (P<0 0 5 ) ,提示颈动脉的病变与冠状动脉病变之间有良好的相关性 (r=0 4 5 ,P <0 0 5 ) ,且外周动脉粥样硬化的程度与冠状动脉病变的程度密切相关。结论　通过对颈动脉的超声检测 ,可以早期发现冠状动脉的病变 ,并可初步预测冠状动脉病变的程度     

Investigation into the suitability of a portable psychometric device to be used in the field: an illicit drugs field investigation

RATIONALE: Driving performance is easily disrupted as a direct consequence of the use of alcohol, licit and illicit drugs. The use of such drugs has a high degree of correlation with increased accident risk. Europe wide research projects into drugged driving have called for the development of a portable objective device capable of screening those impaired through drug use which can be used at the roadside. OBJECTIVE: This study investigated the cognitive and psychomotor performance of a cohort of polydrug drug users in field conditions. Volunteers completed a psychometric test battery on a hand held device in music festival conditions. The test battery comprised a critical tracking task (CTT) and a sustained attention to response task (SART). Volunteers also took a breathanalyser and provided a saliva sample for a DOA screen. RESULTS: On the CTT significance was observed for tracking error following response to a peripheral stimulus in the high alcohol (>80 mg/100 ml) illicit drug group (p=0.0090) and approached significance for the low alcohol (<80 mg/100 ml) illicit drug group (p=0.088). For the SART, incorrect presses to the target stimulus was impaired for volunteers in both the low (<80 mg/100 ml) alcohol illicit drug group (p=0.0080) and the high alcohol (>80 mg/100 ml) illicit drug group (p=0.0415). Discrimination analysis demonstrated that the impairment device was able to discriminate between those individuals who had consumed neither alcohol nor drugs (94.12%), those in the low alcohol drug group (46.67%) and those in the high alcohol drug group (60.00%). CONCLUSION: It is possible to derive an impairment ratio. Further research will demonstrate whether this device could significantly contribute to drug driving detection and road traffic safety.