[Determination of triclocarban and triclosan in urine by QuEChERS extraction and ultra-performance liquid chromatography-tandem mass spectrometry].

Objective: To establish a method for the determination of triclocarban (TCC) and triclosan (TCS) in urine by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) after purification by QuEChERS. Methods: In May 2022, urine samples were extracted by acetonitrile, purified by QuEChERS, separated by Waters Acquity UPLC BEH C18 column (100 mm×2.1 mm, 1.7 µm), and eluated with water-acetonitrile as mobile phase gradient at a flow rate of 0.3 ml/min. The detection was conducted in negative ion mode (ESI(-)) and multiple reaction monitoring (MRM) scanning, it was quantified with a internal standard method, and the methodology was verified. Results: The linear ranges of TCC and TCS were 0.5-100.0 µg/L and 1.0-100.0 µg/L, and the correlation coefficients were 0.9997 and 0.9991, respectively. The limits of detection and quantitation of TCC and TCS were 0.17 and 0.33 µg/L, and 0.5 and 1.0 µg/L, respectively. The recoveries of TCC and TCS were 100.1%-102.8% and 96.7%-108.6%, and the relative standard deviations were 4.9%-6.7% and 4.1%-8.3%, respectively, at 2.0, 10.0 and 80.0 µg/L. Conclusion: QuEChERS-UPLC-MS/MS method is simple, rapid, sensitive and reproducible, and can be used for rapid and accurate simultaneous detection of TCC and TCS exposure levels in occupational population.

[Regulatory effect of Ac-SDKP on phosphorylated heat shock protein 27/SNAI1 pathway in silicotic rats].

Objective: To study the effect of anti-fibrotic tetrapeptide N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) on phosphorylated heat shock protein 27 (P-HSP27) and zinc finger family transcriptional repressor 1 (SNAI1) expression to explore the anti-silicosis fibrosis effect of Ac-SDKP. Methods: In December 2014, the rat silicosis animal model was prepared by one-time bronchial infusion of silicon dioxide (SiO(2)) dust. 80 SPF healthy adult Wistar rats were selected, and the rats were divided into 8 groups according to the random number table method, 10 in each group. Model control group for 4 weeks (feeding for 4 weeks) , model control group for 8 weeks (feeding for 8 weeks) : bronchial perfusion with normal saline 1.0 ml per animal. Silicosis model group for 4 weeks (feeding for 4 weeks) and silicosis model group for 8 weeks (feeding for 8 weeks) : bronchial perfusion of 50 mg/ml SiO(2) suspension 1.0 ml per animal. Ac-SDKP administration group for 4 weeks (feeding for 4 weeks) , Ac-SDKP administration group for 8 weeks (feeding for 8 weeks) : Ac-SDKP 800 µg·kg(-1)·d(-1) was administered by intraperitoneal pump. Ac-SDKP preventive treatment group: 48 h after Ac-SDKP 800 µg·kg(-1)·d(-1) administration, bronchial perfusion of SiO(2) suspension 1.0 ml per animal, raised for 8 weeks. Ac-SDKP anti-fibrosis treatment group: after bronchial perfusion of 1.0 ml of SiO(2) suspension for 4 weeks, Ac-SDKP 800 µg·kg(-1)·d(-1) was administered for 4 weeks. Western blotting was used to detect the expression of P-HSP27, SNAI1, α-smooth muscle actin (α-SMA) , and collage typeⅠ and Ⅲ in each group. The expression of P-HSP27 and SNAI1 was detected by immunohistochemistry, and the co-localized expression of P-HSP27 and α-SMA was detected by laser confocal microscopy. Results: Compared with the model control group, the expressions of P-HSP27, SNAI1, α-SMA, and collage typeⅠ and Ⅲ in the silicosis fibrosis area of the rats in the silicosis model group were enhanced, and the differences were statistically significant (P<0.05) . After Ac-SDKP intervention, compared with silicosis model group for 8 weeks, the expressions of P-HSP27, SNAI1 α-SMA, and collage typeⅠ and Ⅲ in the Ac-SDKP preventive and anti-fibrosis treatment groups were significantly decreased, and the differences were statistically significant (P<0.05) . However, the expressions of P-HSP27 SNAI1, and collage typeⅠ and Ⅲ between the Ac-SDKP administration group and the model control group did not change significantly, and the differences were not statistically significant (P>0.05) . Laser confocal results showed that the positive cells expressing P-HSP27 and α-SMA in the lung tissue of the silicosis model group were more than those in the model control group. Compared with the silicosis model group, the Ac-SDKP prevention and anti-fibrosis treatment groups expressing the positive cells of P-HSP27 and α-SMA decreased. Compared with the model control group for 8 weeks, there were some double-positive cells expressing P-HSP27 and α-SMA in the nodules of the silicosis model group for 8 weeks. Conclusion: Ac-SDKP may play an anti-silicic fibrosis effect by regulating the P-HSP27/SNAI1 pathway.

[The effect of a breathing trainer on relieving airway pressure caused by active cough in patients with mechanical ventilation].

Objective: To explore the effect of a breathing trainer on relieving the peak airway pressure caused by forced exhalation at the end of deep inspiration, gentle coughing at the end of calm inspiration and forced coughing at the end of deep inspiration in patients undergoing mechanical ventilation. Methods: From July to September 2018, 15 patients undergoing mechanical ventilation were selected from the First Affiliated Hospital of Guangzhou Medical University, including 5 patients with invasive ventilation (3 with tracheotomy and 2 with endotracheal intubation), and 10 patients with non-invasive ventilation through mask. The patients included 14 males and 1 female, aging 48-79 years, with an average age of (68±10) years. A Breathing Trainer developed by both Dongguan Yongsheng Medical Products Co., Ltd. and Guangzhou Institute of Respiratory Health was used to relieve the peak airway pressure. A one-way expiratory valve connected with a spring at the expiratory end of the Breathing Trainer was not opened until the pressure inside the airway was higher than 20 cmH(2)O (1 cmH(2)O=0.098 kPa), and opened completely when the pressure was higher than 35 cmH(2)O. Both before and after the Breathing Trainer was connected to the respiratory circuit, the patients were asked to exhale hard at the end of deep inspiration, to cough gently at the end of calm inspiration and to cough forcefully at the end of deep inspiration and the airway pressure were measured respectively. Each action was tested 3 times, and the interval time of each test was 1 min, and the interval of each action was 10 min. Results: Among the patients with tracheotomy or endotracheal intubation for invasive mechanical ventilation, when the patients exhaled hard at the end of deep inspiration,coughed gently at the end of gentle inspiration and coughed forcefully at the end of deep inspiration, the peak airway pressure measured before the ventilation circuit was connected to the Breathing Trainer was (30.0±4.5), (31.4±5.0) and (34.9±5.0)cmH(2)O, respectively, which was significantly higher than that after the ventilation circuit was connected to the Breathing Trainer(26.3±2.9), (26.7±3.5) and (29.0±4.1) cmH(2)O (all P<0.01). Among the patients with non-invasive mechanical ventilation wearing face masks, when the patients exhaled hard at the end of deep inspiration, coughed gently at the end of gentle inspiration and coughed forcefully at the end of deep inspiration, the peak airway pressure was (17.7±1.9), (16.6±2.5) and (18.9±2.5) respectively, before the ventilation circuit was connected to the Breathing Trainer, and was (18.9±2.5), (16.3±1.9) and (18.8±2.0) cmH(2)O respectively, after the ventilation circuit was connected to the Breathing Trainer. There was no significant difference between them (P>0.05). Conclusion: The application of Breathing Trainer in the mechanical ventilation circuit of tracheotomy or endotracheal intubation could significantly reduce the peak airway pressure caused by hard exhalation and cough. It could be used as an active cough assist device for mechanical ventilation patients to prevent high airway pressure.

Dietary Fat Intake and Cognitive Function among Older Populations: A Systematic Review and Meta-Analysis.

OBJECTIVE: The associations between dietary fat intake and cognitive function are inconsistent and inconclusive. This study aimed to provide a quantitative synthesis of prospective cohort studies on the relationship between dietary fat intake and cognitive function among older adults. METHODS: PubMed, EMBASE, PsycINFO and Web of Science databases were searched for prospective cohort studies published in English before March 2018 reporting cognitive outcomes in relation to dietary fat intake. Four binary incident outcomes included were mild cognitive impairment (MCI), dementia, Alzheimer disease (AD) and cognitive impairment. The categories of dietary fat intake were based on fat consumption or the percentage of energy from fat consumption, including dichotomies, tertiles, quartiles and quintiles. The relative risk (RR) with the corresponding 95% confidence intervals (CIs) was pooled using a random effects model. RESULTS: Nine studies covering a total of 23,402 participants were included. Compared with the lowest category of consumption, the highest category of saturated fat intake was associated with an increased risk of cognitive impairment (RR = 1.40; 95% CI: 1.02-1.91) and AD (RR: 1.87, 95% CI: 1.09-3.20). The total and unsaturated fat intake was not statistically associated with cognitive outcomes with significant between-study heterogeneity. CONCLUSION: This study reported a detrimental association between saturated fat intake and cognitive impairment and mixed results between unsaturated fat intake and selected cognitive outcomes. Given the substantial heterogeneity in the sample size and methodology used across studies, the evidence presented here should be interpreted with caution.

[A Meta-analysis on the relations between short-term exposure to PM(2.5) and both mortality and related emergency visits in China].

Objective: To carry out a quantitative estimate that related to the effects of short-term exposure to PM(2.5) on all-cause mortality and emergency visits in China by using the systematic review and Meta-analysis. Methods: We selected all the studies published before March 2018 from China National Knowledge Infrastructure, Wanfang database, PubMed and EMBASE and data on relative risk (RR), excess risk (ER) and their 95%CIs: appeared in these papers were extracted. According to the differences in the size or direction (heterogeneity) of the results, we computed summary estimates of the effect values using a random-effect or fixed effect model. We also conducted the subgroup analysis and Meta-analysis to have assessed the selected studies for the evidence of study bias. Results: A total of 33 original studies, indexed in databases, were identified. Among those studies, 39 sets of data on mortality and 4 sets of data on emergency were valid to show that within the daily concentration range from 47.7 to 176.7 µg/m(3), for 10 µg/m(3) increases in PM(2.5) concentrations, it would increase the daily numbers of deaths by 0.49% (95%CI: 0.39%-0.59%) and 0.30% (95%CI: 0.10%-0.51%) for all-cause deaths and all-cause emergency-room visits, respectively. For subgroup analysis, the combined effect of PM(2.5) in causing short-term all-cause deaths in the northern areas (ER=0.42%, 95%CI: 0.30%-0.54%) seemed lower than that in the southern areas (ER=0.63%, 95%CI: 0.44%-0.82%). The combined effect of PM(2.5) concentration below 75 µg/m(3) (ER=0.50%, 95%CI: 0.37%-0.62%) was higher than that of PM(2.5) concentration ≥75 µg/m(3) (ER=0.39%, 95%CI: 0.26%-0.52%). Conclusion: Within the concentration range from 47.7 to 176.7 µg/m(3), short-term exposure to current level of PM(2.5) might increase both the all-cause daily mortality and daily emergency visits in China.

Cardioprotection with beta-blockers: myths, facts and Pascal's wager.

Beta-blockers were documented to reduce reinfarction rate more than 3 decades ago and subsequently touted as being cardioprotective for a broad spectrum of cardiovascular indications such as hypertension, diabetes, angina, atrial fibrillation as well as perioperatively in patients undergoing surgery. However, despite lowering blood pressure, beta-blockers have never shown to reduce morbidity and mortality in uncomplicated hypertension. Also, beta-blockers do not prevent heart failure in hypertension any better than any other antihypertensive drug class. Beta-blockers have been shown to increase the risk on new onset diabetes. When compared with nondiuretic antihypertensive drugs, beta-blockers increase all-cause mortality by 8% and stroke by 30% in patients with new onset diabetes. Beta-blockers are useful for rate control in patients with chronic atrial fibrillation but do not help restore sinus rhythm or have antifibrillatory effects in the atria. Beta-blockers provide symptomatic relief in patients with chronic stable angina but do not reduce the risk of myocardial infarction. Adverse effects of beta-blockers are common including fatigue, dizziness, depression and sexual dysfunction. However, beta-blockers remain a cornerstone in the management of patients having suffered a myocardial infarction and for patients with heart failure. Thus, recent evidence argues against universal cardioprotective properties of beta-blockers but attest to their usefulness for specific cardiovascular indications.

Principal uses of myocardial perfusion scintigraphy in the management of patients with known or suspected coronary artery disease.

The use of myocardial perfusion single photon emission computed tomography (SPECT) has undergone considerable expansion and evolution over the past 2 decades. Although myocardial perfusion imaging was first conceived as a noninvasive diagnostic tool for determining the presence or absence of coronary artery disease, its prognostic value is now well established. Thus, identification of patients at risk for future cardiac events has become a primary objective in the noninvasive evaluation of patients with chest pain syndromes and among patients with known coronary artery disease. In particular, the ability of myocardial perfusion SPECT to identify patients at low (< 1%), intermediate (1% to 5%) or high (> 5%) risk for future cardiac events is essential to patient management decisions. Moreover, previous studies have conclusively shown the incremental prognostic value of myocardial perfusion SPECT over clinical and treadmill exercise data in predicting future cardiac events. This report addresses the current role and new developments, with respect to the use of myocardial perfusion imaging, in determining patient risk for cardiac events and the cost-effective integration of such information into patient management decisions.

Clinical impact of arrhythmias on gated SPECT cardiac myocardial perfusion and function assessment.

BACKGROUND: We reported previously that mean quantified cardiac functional parameters computed by one gated single photon emission computed tomography (SPECT) technique were not significantly altered by common gating errors. However, it is not known to what extent other gated SPECT approaches that are based on different ventricular modeling assumptions are influenced by arrhythmias, nor are the effects of gating errors on visual analyses and their subsequent clinical implications known. METHODS: Projection data for 50 patients (aged 64 +/- 12 years; 68% men; 76% with myocardial perfusion defects) undergoing technetium-99m sestamibi gated SPECT who were in sinus rhythm during data acquisition were altered to simulate common arrhythmias. To determine quantitative effects, we performed calculations for original control and altered images by Gaussian myocardial detection (Quantitative Gated SPECT [QGS] program) and by wall thickening derived from gated perfusion polar maps (Emory Cardiac Toolbox program). To evaluate visual assessment in control and simulated-arrhythmia tomograms, 2 experienced blinded observers independently interpreted perfusion from polar maps and wall motion and thickening from tomographic cines, using a 4-point scale. RESULTS: Although mean functional parameters were scarcely altered, paired t tests showed ejection fraction fluctuations to be significantly different from control values, causing patients to change between abnormal and normal ejection fraction categories (2% of patients by QGS and 14% by Emory Cardiac Toolbox). Visual examination of QGS polar perfusion and function maps showed changes for 72% of cases, although in only 4% were these considered to have potential clinical consequences. The kappa statistic for visual analysis of concordance between control and arrhythmia readings showed that agreement was "excellent" for perfusion, "good" for motion, and "marginal" for thickening. CONCLUSIONS: As with quantitative measurements, thickening is the parameter most prone to error in the presence of arrhythmias. It is important to test data for gating errors to avoid potentially erroneous measurements and visual readings.

Development and application of normal limits for left ventricular ejection fraction and volume measurements from 99mTc-sestamibi myocardial perfusion gates SPECT.

UNLABELLED: Gated SPECT is a reproducible method for assessing left ventricular volume (LVV) and left ventricular ejection fraction (LVEF) from 99mTc-sestamibi myocardial perfusion imaging studies. LVV and LVEF measurements by this approach correlate well with those obtained from other cardiovascular imaging techniques. Nevertheless, the lack of criteria for abnormal test findings has limited the potential clinical application of this new imaging technique. METHODS: Gated SPECT measurements were evaluated for 214 patients with a low Bayesian likelihood (< 10%) of coronary artery disease (CAD) before performance of 99mTc-sestamibi stress-rest myocardial perfusion SPECT. The patients were grouped into normotensive patients (n = 98), hypertensive patients without left ventricular hypertrophy (LVH) (n = 80), and hypertensive patients with LVH on resting electrocardiography (n = 36). Gated SPECT measurements for left ventricular end-diastolic volume (LVEDV) index, left ventricular end-systolic volume (LVESV) index, and LVEF were obtained according to a published method, using a modified Simpson's rule technique. RESULTS: Similar results were obtained for mean LVV and LVEF measurements between normotensive patients and hypertensive patients without LVH. Hence, these groups were combined (as group 1). By contrast, hypertensive patients with LVH (group 2), had significantly lower LVEF values (P = 0.01) and higher mean LVESV index values than normotensive patients (P = 0.03). Sex differences were marked: women had significantly higher mean resting LVEF values than men (P < 0.0001) and significantly lower mean resting LVEDV index values (P < 0.0001). A significant relationship was seen between LVEDV index and LVEF (r = -0.60; P < 0.0001) and between LVEDV index and heart rate (r = -0.26; P < 0.001). The normal limits were LVEF > or = 41% in men and > or = 49% in women, LVEDV index < or = 76 mL/m2 in men and < or = 57 mL/m2 in women, and LVESV index < or 38 mL/m2 in men and < or =26 mL/m2 in women. Among hypertensive patients, 22% with LVH had an abnormally low LVEF and 19% had an increased LVEDV index according to these test criteria. By contrast, no hypertensive patients without LVH had an abnormally low LVEF, and only 6% had volume abnormalities. CONCLUSION: Using a cohort of low-likelihood patients, we generated sex-specific normal limits for LVV and LVEF for myocardial perfusion gated SPECT. Application of these findings resulted in the detection of occult left ventricular dysfunction in approximately one fifth of hypertensive patients for whom concomitant LVH was found through resting electrocardiography. These normal limits can now be evaluated prospectively for their potential clinical value.

Echocardiographic validation of gated SPECT ventricular function measurements.

UNLABELLED: Left ventricular (LV) volumes are valuable prognostic indicators in the management of coronary artery disease and traditionally have been obtained by x-ray contrast angiography or echocardiography. There now are several scintigraphic methods to compute volumes that are based on different LV modeling assumptions. Both the reasons that calculations from different nuclear techniques can disagree with one another and the relationship of these values to the more conventional echocardiographic measurements must be investigated thoroughly for calculations to be interpretable for individual patients. METHODS: Echocardiographic volumes were determined in 33 retrospective subjects with coronary artery disease (mean age, 61 +/- 12 y; 42% men; 70% with abnormal perfusion and 58% with abnormal segmental wall motion) using the modified Simpson's rule technique applied to digitized apical 4-chamber and apical 2-chamber views of 4 averaged heartbeats. These volumes were compared with those from 3 gated SPECT methods based on Simpson's rule LV modeling similar to standard echocardiographic algorithms (SPECT EF from St. Luke's-Roosevelt Hospital) (method 1), Gaussian myocardial count profile curve fitting (QGS from Cedars-Sinai Medical Center) (method 2), and an endocardial model based on perfusion sampling and count-based thickening (Cardiac Toolbox from Emory University) (method 3). RESULTS: By ANOVA, there were no significant differences among ejection fractions (EFs), but there were for volumes. Paired t test analysis showed volumes from methods 2 and 3 to be significantly larger than echocardiographic volumes and larger than those of method 1. Linear regression analysis comparing gated SPECT and echocardiographic volumes showed a nearly identical strong correlation (r = 0.92; P < 0.000001) for all 3 methods. Excellent correlation also was found among gated SPECT volumes from the 3 methods (r = 0.94). Bland-Altman analysis and t tests showed that method 1 volumes (70 +/- 61 mL) were the same as for echocardiography (77 +/- 55 mL), but volumes were overestimated by method 2 (105 +/- 74 mL) and method 3 (127 +/- 92 mL), particularly for larger volumes. Pearson coefficients for EFs compared with echocardiography were r = 0.82, 0.75, and 0.72 for methods 1-3, respectively. EFs correlated strongly among the 3 gated SPECT methods (r = 0.86-0.92). The Fisher z test showed no differences among these methods for any of the volume or EF linear correlation analyses. CONCLUSION: All gated SPECT parameters correlated well with echocardiographic values. However, the gated SPECT method for which underlying assumptions most closely resembled those commonly used in echocardiography produced mean volume values closest in agreement with echocardiographic measurements.

Saponins isolated from Allium chinense G. Don and antitumor-promoting activities of isoliquiritigenin and laxogenin from the same drug.

Investigation of the Chinese crude drug "Xiebai," the bulbs of Allium chinense G. Don (Liliaceae), led to the isolation of 2 saponins, xiebai-saponin I (laxogenin 3-O-beta-xylopyranosyl (1-->4)-[alpha-arabinopyranosyl (1-->6)-beta-glucopyranoside) (1) and laxogenin 3-O-alpha-arabinopyranosyl (1-->6)-beta-glucopyranoside (2), and the aglycone, laxogenin (3), together with 2 chalcones, isoliquiritigenin (4) and isoliquiritigenin-4-O-glucoside (5), and beta-sitosterol glucoside (6). Compounds 1-5 were tested in vitro for their inhibitory effect on the 12-O-tetradecanoylphorbol-13-acetate (TPA)-stimulated 32Pi-incorporation into phospholipids of HeLa cells. In addition to this, laxogenin (3) was proven to have an antitumor-promoting activity in a two-stage lung carcinogenesis experiment.

Influence of arrhythmias on gated SPECT myocardial perfusion and function quantification.

UNLABELLED: Despite the importance of R-wave gating myocardial perfusion tomography for ventricular function assessment, neither prevalence of gating errors nor their influence on quantified cardiac parameters has been studied. METHODS: Arrhythmia-induced anomalies in curves of counts versus projection angle for each R-wave segment were detected visually and algorithmically. Arrhythmia prevalence was tabulated for 379 patients (group 1) with prospective coronary artery disease (mean age 63+/-13 y, 47% male). Myocardial counts were analyzed from all reconstructed cinematic midventricular slices to assess arrhythmia effects on percentage of systolic count increase, generally assumed to equal percentage of wall thickening. In a separate retrospective analysis of 41 patients (group 2), with coronary artery disease (mean age 64+/-12 y, 68% male) having no significant arrhythmias, 36 of whom also underwent equilibrium radionuclide angiography, original projection data were altered to simulate arrhythmia-induced aberrant count patterns to evaluate effects on ventricular function and perfusion measurements. RESULTS: Group 1 patients consisted of 26% without gating errors, 32% with count losses only in the last R-wave interval due to inconsistent transient increase of heart rate, 24% with count decreases in several late intervals due to consistently variable rates, 8% with early interval count increases paired with late interval count decreases due to ectopic beats and 9% with erratic count changes due to atrial fibrillation. Observed count patterns were strongly associated (P < 10(-3)) with arrhythmias detected by electrocardiogram monitoring. In group 2 simulations, ventricular volumes changed by only 2%+/-9% and ejection fraction (EF) by only 1%+/-4% from control values and correlated linearly (r> or = 0.96) with control values for all simulated arrhythmias. SPECT and equilibrium radionuclide angiography EFs correlated similarly (r = 0.85-0.89) for control and all simulations. Percentage changes from control in perfusion defect extent and severity were larger than processing reproducibility limits, the largest change being for atrial fibrillation. Control wall thickening was 38%+/-17%, significantly lower (P < 10(-6)) than for simulated arrhythmias, reflecting similar observations for group 1 patients. CONCLUSION: Even though ventricular volumes and EFs were affected minimally by arrhythmias, both perfusion analysis and wall thickening were compromised. Consequently, quality assurance of gating may be critically important for obtaining accurate quantified parameters.

Successful intracoronary thrombolysis in cocaine-associated acute myocardial infarction.

We describe a case of cocaine-associated acute myocardial infarction managed by cardiac catheterization and intracoronary thrombolysis. Based on this and other reported cases, it appears that an invasive approach to the management of cocaine-associated acute myocardial infarction is advantageous over intravenous thrombolysis. Such a strategy would define the pathophysiology of acute myocardial infarction in the setting of cocaine use and allow mechanical intervention should pharmacologic therapy be unsuccessful.

Improved Doppler echocardiographic assessment of the left atrial appendage by peripheral vein injection of sonicated albumin microbubbles.

We evaluated the usefulness of peripherally injected sonicated albumin microbubbles in transesophageal echo-Doppler cardiographic assessment of the left atrial appendage in 19 patients (age 61 +/- 19 [range 21 to 86] years; 12 [63%] women). Multiplane transesophageal echocardiography was performed before and after intravenous injection of sonicated albumin, and the left atrial appendage image and Doppler flow signal quality were assessed by a grading system of 0 to 3+ (0 = poor, 1 + = adequate, 2+ = good, and 3+ = excellent). Microbubbles appeared in the left atrium in 15 (79%) of 19 patients and completely opacified the left atrial appendage in 7 (37%) of 19 patients. Left atrial appendage maximal and minimal areas by planimetry were similar before and after contrast injection, although image quality improved in 13 (68%) of 19 patients (echocardiographic grade 1.8 +/- 0.6 vs 2.6 +/- 0.5, p< 0.001). Similarly, left atrial appendage peak emptying and peak filling Doppler flow velocities did not change before and after contrast injection, although Doppler flow signal quality improved in 12 (63%) of 19 patients (Doppler grade 1.6 +/- 0.5 vs 2.1 +/- 0.8, p < 0.05). Overall, contrast injection improved left atrial appendage echocardiographic or Doppler quality in 16 (84%) of 19 patients. Thus peripheral vein injection of sonicated albumin microbubbles can improve the assessment of left atrial appendage structure and function by transesophageal echocardiography.

Prevalence of vitamin B12 deficiency among geriatric outpatients.

BACKGROUND: Healthy people can have low levels of cobalamin (vitamin B12) without symptoms or signs of cobalamin deficiency. Early detection of deficiency is imperative for treatment to be effective. Development of radioimmunoassay tests has greatly improved accurate determination of cobalamin (Cbl) levels. Nevertheless, results of studies of Cbl deficiency vary widely because of the variety of populations studied. METHODS: In a prospective study, we tested 100 consecutive, unselected geriatric outpatients in a primary care setting to determine the prevalence of cobalamin deficiency. All patients, 65 years of age or older, who visited the office of one of the authors during a period of 11 consecutive working days, had their serum Cbl level checked. If the level was 299 pg/mL or lower, serum intrinsic factor and parietal cell antibodies, serum gastrin, part 1 Schilling test, serum methylmalonic acid, and total homocysteine were done, when possible, for the diagnosis of type A gastritis and intracellular Cbl deficiency. RESULTS: Sixteen percent of geriatric outpatients had serum Cbl levels of 200 pg/mL or below, and 21% had levels between 201 and 299 pg/mL. Among the 16 patients with levels < or = 200 pg/mL, 2 patients had macrocytic anemia, 3 patients had peripheral neuropathy, and 8 patients had type A gastritis. Among the 21 patients with levels of 201 to 299 pg/mL, 2 patients had peripheral neuropathy, 9 patients had type A gastritis, and none of the patients had macrocytic anemia. Among the patients whose methylmalonic acid and total homocysteine levels were determined, the results were high in 80% of those with Cbl levels < or = 200 pg/mL and in 33% of those with levels from 201 to 299 pg/mL. CONCLUSIONS: The prevalence of Cbl deficiency in geriatric outpatients was found to be higher than in any recent report. The lower limit of the normal range for Cbl level should be increased to 300 pg/mL.

Human teeth with and without dental caries studied by visible luminescent spectroscopy.

The visible emission spectra and fluorescent life-time from decayed and nondecayed regions of teeth were measured and compared. The spectrum from carious lesions is different from that of noncarious tooth regions. This may offer a non-X-ray method for diagnosing dental caries in humans.