Implementation of a stable, high-power optical lattice for quantum gas microscopy.

We describe the design and implementation of a stable high-power 1064 nm laser system to generate optical lattices for experiments with ultracold quantum gases. The system is based on a low-noise laser amplified by an array of four heavily modified, high-power fiber amplifiers. The beam intensity is stabilized and controlled with a nonlinear feedback loop. Using real-time monitoring of the resulting optical lattice, we find the stability of the lattice site positions to be well below the lattice spacing over the course of hours. The position of the harmonic trap produced by the Gaussian envelope of the lattice beams is stable to about one lattice spacing and the long-term (six-month) relative root-mean-square stability of the lattice spacing itself is 0.5%.

Automated rodent in situ muscle contraction assay and myofiber organization analysis in sarcopenia animal models.

Age-related sarcopenia results in frailty and decreased mobility, which are associated with increased falls and long-term disability in the elderly. Given the global increase in lifespan, sarcopenia is a growing, unmet medical need. This report aims to systematically characterize muscle aging in preclinical models, which may facilitate the development of sarcopenia therapies. Naïve rats and mice were subjected to noninvasive micro X-ray computed tomography (micro-CT) imaging, terminal in situ muscle function characterizations, and ATPase-based myofiber analysis. We developed a Definiens (Parsippany, NJ)-based algorithm to automate micro-CT image analysis, which facilitates longitudinal in vivo muscle mass analysis. We report development and characterization of translational in situ skeletal muscle performance assay systems in rat and mouse. The systems incorporate a custom-designed animal assay stage, resulting in enhanced force measurement precision, and LabVIEW (National Instruments, Austin, TX)-based algorithms to support automated data acquisition and data analysis. We used ATPase-staining techniques for myofibers to characterize fiber subtypes and distribution. Major parameters contributing to muscle performance were identified using data mining and integration, enabled by Labmatrix (BioFortis, Columbia, MD). These technologies enabled the systemic and accurate monitoring of muscle aging from a large number of animals. The data indicated that longitudinal muscle cross-sectional area measurement effectively monitors change of muscle mass and function during aging. Furthermore, the data showed that muscle performance during aging is also modulated by myofiber remodeling factors, such as changes in myofiber distribution patterns and changes in fiber shape, which affect myofiber interaction. This in vivo muscle assay platform has been applied to support identification and validation of novel targets for the treatment of sarcopenia.

Relationships between obesity and the clinical severity of psoriasis in Taiwan.

BACKGROUND: Obesity has been found to be associated with an increased risk of psoriasis in general population. However, studies addressing the relationship between obesity and clinical severity of psoriasis are still scarce, especially in Asian people. OBJECTIVES: In this study, we investigated the relationship between levels of obesity and the clinical severity of psoriasis in Taiwanese psoriasis patients. METHODS: This was a hospital-based cross-sectional study. A total of 399 patients with chronic plaque psoriasis were recruited. Their body mass index (BMI) was calculated as weight in kilograms divided by height in metres squared and was categorized into four groups (BMI < 24, normal; 24 or= 30, moderate-to-severe obesity). Disease severity was assessed by Psoriasis Area and Severity Index. Cumulative logistic regression models were used to estimate the association between BMI and Psoriasis Area and Severity Index. RESULTS: After adjusting for potential confounders (age, gender, cigarette smoking and duration of disease), moderate-to-severe obesity was significantly associated with an increased risk of clinically more severe psoriasis when compared with normal BMI [odds ratio, 2.70; 95% confidence interval,1.42-5.11]. There is a significant linear trend for clinically more severe psoriasis across increasing of BMI categories (P for trend = 0.004). The effect of obesity on the severity of psoriasis was greater in men than in women (test for interaction, P = 0.03). CONCLUSIONS: In psoriasis patients, obesity is associated with a more severe disease, especially in men. Bodyweight control may be important for the management of psoriasis.

Improvement in the growth performance of white shrimp, Litopenaeus vannamei, by a protease-producing probiotic, Bacillus subtilis E20, from natto.

AIMS: To isolate and identify a benefic bacterium, Bacillus subtilis E20, from natto (fermented soybeans), and incorporate it into shrimp feed to promote shrimp growth performance. METHODS AND RESULTS: A protease-producing bacterium, E20, isolated from natto was identified as B. subtilis by an API 50 CHB kit and the 16S rDNA sequence. B. subtilis E20 was able to grow at a broad range of temperatures (10-50 degrees C), pH values (5-10), and NaCl levels (0-9%). The best culture conditions for B. subtilis E20 to produce the protease were 40 degrees C, a pH of 6-8 and 0% NaCl. No shrimp died after being injected with B. subtilis E20 [up to 10(9) colony-forming units (CFU) per shrimp]. Bacillus subtilis E20 was incorporated in diets at the levels of 0 (control), 10(6), 10(7), and 10(8) CFU kg(-1) for shrimp grow-out culture, and results showed that after feeding on B. subtilis E20-containing diets (10(8) CFU kg(-1) of diet), shrimp had excellent growth performance and production compared to the control because protease activities in the digestive tract were improved by B. subtilis E20. CONCLUSIONS: Bacillus subtilis E20 isolated from natto is a great protease producer and is able to improve shrimp growth performance through increasing the digestibility of food. SIGNIFICANCE AND IMPACT OF THE STUDY: Results suggest that B. subtilis E20 is a potential candidate for use as a probiotic to improve shrimp growth performance, and consequently reduce feed costs.

Prevalence of hospital infection and antibiotic use at a university medical center in Hong Kong.

Hospital infection prevalence surveys were performed in our 1400-bed University medical centre in Hong Kong from 1985 to 1988. We investigated the rates of four major hospital-acquired infections (HAIs) (pneumonia, symptomatic urinary tract infection, surgical site infection and laboratory-confirmed bloodstream infection) in order to identify current distribution and any changes after 15 years. A one-day point prevalence study was performed on 7 September 2005. All inpatients were surveyed for HAIs, community-acquired infections (CAIs), risk factors, pathogenic isolates and antibiotics prescribed. Infections were diagnosed according to Centers for Disease Control and Prevention (CDC) criteria. In total, 1021 patients were surveyed; of these, 41 had 42 HAIs (4% prevalence) and 389 (38%) were receiving antibiotics. The commonest HAI was pneumonia (1.4%) followed by bloodstream infection (0.9%) and symptomatic urinary tract infection (0.8%). The prevalence of postoperative surgical site infection was 5.6%. The nosocomial prevalence rate was highest in the Intensive Care Unit, followed by the Pediatric and Neonatal Intensive Care Units, Children's Cancer Centre/Bone Marrow Transplant Unit and Orthopaedics with Traumatology. Meticillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa were the commonest pathogens. The rates are significantly lower than previously and reflect the increased resources for infection control made available following the outbreak of severe acute respiratory syndrome (SARS).

Behavioral and biochemical characterization of a mutant mouse strain lacking D-amino acid oxidase activity and its implications for schizophrenia.

D-amino acid oxidase (DAO) degrades D-serine, a co-agonist at the NMDA receptor (NMDAR). Hypofunction of the NMDAR has been suggested to contribute to the pathophysiology of schizophrenia. Intriguingly, DAO has been recently identified as a risk factor for schizophrenia through genetic association studies. A naturally occurring mouse strain (ddY/DAO-) has been identified which lacks DAO activity. We have characterized this strain both behaviorally and biochemically to evaluate DAO as a target for schizophrenia. We have confirmed that this strain lacks DAO activity and shown for the first time it has increased occupancy of the NMDAR glycine site due to elevated extracellular D-serine levels and has enhanced NMDAR function in vivo. Furthermore, the ddY/DAO- strain displays behaviors which suggest that it will be a useful tool for evaluation of the clinical benefit of DAO inhibition in schizophrenia.

Foreign body-induced aorto-oesophageal fistula: a review of five cases and their management.

Foreign body-induced aorto-oesophageal fistula is a rare cause of massive upper gastro-intestinal bleeding and, in the absence of a timely diagnosis and surgical intervention, can be fatal. During a period of 25 years, five patients with foreign body-induced aorto-oesophageal fistula underwent surgery in our department. Three patients survived. All survivors required more than one surgical intervention. The clinical course of these five patients and the management of this potentially fatal condition are reviewed.

Preliminary evidence on the measurement properties of the Chinese version of the Child Health Questionnaire, parent form (CHQ-pF50) and child form (CHQ-CF87).

UNLABELLED: The objective of this study was to evaluate the reliability and construct validity of the Chinese parent form (PF50) and child form (CF87) of the Child Health Questionnaire (CHQ). METHODS: To assess the construct validity and reliability of the Chinese versions, we invited 1099 parents of healthy children and 816 school children to complete the Chinese CHQ-PF50 and CHQ-CF87, respectively. RESULTS: Psychometric analysis on item convergent validity and discriminant validity showed > or = 99% rates of success for all 10 scales in the CF87 and > or = 94% for all but one scale in the PF50, the exception being general health scale (86%). We observed minimal floor effects for both questionnaires, but substantial ceiling effects for five scales in both the PF50 and CF87 (physical functioning, role-emotional/behavioral, role-physical, bodily pain and family activities). A substantially lower ceiling effect was observed for the physical scale and bodily pain in the CF87 (19% and 25%, respectively) relative to the PF50 (46% and 42%, respectively). The median alpha coefficient for CF87 and PF50 was 0.90 (range, 0.80-0.94) and 0.78 (range, 0.44-0.88), respectively. CONCLUSIONS: Our findings suggest that the Chinese CHQ-PF50 and CHQ-CF87 are robust and sufficiently reliable for group comparisons and perhaps also for use in other Chinese populations.

Necrotic cardiac haemangioma masquerading as sepsis with disseminated intravascular coagulation.

Cardiac haemangiomas are exceptionally rare benign vascular tumours. We report a case of cardiac haemangioma presenting with pyrexia of unknown origin and clinical features simulating sepsis with disseminated intravascular coagulation. The clinical course was complicated by systemic embolism.

Evolution of the management approach for pulmonary atresia with intact ventricular septum.

OBJECTIVE: To review the evolution of the management approach for pulmonary atresia with intact ventricular septum (PAIVS) in the past two decades and to assess its impact on patient outcomes. DESIGN AND PATIENTS: Retrospective review of the management and outcomes of 94 patients (55 male patients) with PAIVS diagnosed between July 1980 and August 2003. SETTINGS: Tertiary paediatric cardiac centre. RESULTS: Seven patients died before interventions. Of the remaining 87 patients who underwent intervention at a median age of 9 days (from 1 day to 2 years), 12 had right ventricular outflow tract reconstruction (RVOTR), 42 had closed pulmonary valvotomy (CPV), and 15 had laser assisted valvotomy with balloon valvoplasty. A systemic-pulmonary shunt was inserted in 18 patients, six of whom had subsequent RVOTR (n = 4) or laser assisted valvotomy (n = 2). Since 1990, catheter intervention accounted for 38% (17 of 45) of the right ventricular outflow procedures. The mean (SEM) freedom from reintervention was 93 (7)%, 71 (12)%, and 57 (13)% after RVOTR, 75 (7)%, 40 (8)%, and 14 (6)% after CPV, and 54 (13)%, 24 (12)%, and 16 (10)% after laser assisted valvotomy at one month, six months, and one year, respectively (RVOTR versus CPV, p < 0.001; RVOTR versus laser assisted valvotomy, p = 0.001). Low cardiac output syndrome was significantly less common after catheter intervention than after RVOTR (0% v 44%, p = 0.003) or CPV (0% v 29%, p = 0.01). The overall mean (SEM) survival was 77 (5)% and 70 (5)% at one and five years, respectively, and the overall mortality was 33% (29 of 87). There were no significant differences in survival between the three groups. CONCLUSIONS: Multiple interventions are often required in the treatment algorithm of PAIVS. The shift towards increased use of the transcatheter approach has reduced the occurrence of postprocedural low cardiac output syndrome.

Assessment of left ventricular function long term after arterial switch operation for transposition of the great arteries by dobutamine stress echocardiography.

OBJECTIVES: To use dobutamine stress echocardiography to determine left ventricular (LV) function and wall motion of children long term after arterial switch operation (ASO) for transposition of the great arteries. DESIGN AND PATIENTS: 31 patients (24 boys) with ASO performed at a mean (SD) of 15.5 (4.3) days of life were studied at an age of 9.4 (2.0) years. All had normal coronary angiographic findings. LV echocardiographic indexes, including fractional shortening, ejection fraction, rate corrected velocity of circumferential fibre shortening (VCFc), and wall stress, as well as LV wall motion abnormalities were determined at rest and under dobutamine stress. The results were compared with those of 20 healthy age matched control participants. SETTING: Tertiary paediatric cardiac centre. RESULTS: Fractional shortening, ejection fraction, and VCFc were significantly lower in patients than in controls at rest (all with p < 0.001). Stress-velocity index detected impaired LV contractility in 19 (61%) patients at rest. An older age at operation (p = 0.01), longer bypass (p = 0.01) and circulatory arrest times (p = 0.045), and an unusual coronary artery pattern (p = 0.059) were associated with impaired resting LV contractility. Dobutamine stress echocardiography unmasked wall motion abnormalities in 23 (74%) patients. Exercise myocardial perfusion scan, performed in 22 patients, showed reversible myocardial perfusion defects in 17. These defects corresponded to segments of hypokinesia as detected by dobutamine stress echocardiography. CONCLUSION: A significant proportion of children, albeit asymptomatic, had impaired baseline LV contractility and reversible myocardial perfusion defects and mild wall motion abnormalities on stress after ASO.

Pericardial effusion after open heart surgery for congenital heart disease.

OBJECTIVES: To determine the prevalence and time course of pericardial effusion after open heart surgery for congenital heart diseases and to identify predisposing risk factors. DESIGN AND PATIENTS: Prospective assessment of development of pericardial effusion in 336 patients (163 males) undergoing open heart surgery for congenital heart disease by serial echocardiography on days 5, 7, 14, 21, and 28 postoperatively. SETTING: Tertiary paediatric cardiac centre. RESULTS: The prevalence of pericardial effusion was 23% (77 of 336). Of the 77 patients who developed effusion, 43 (56%) had moderate to large effusions and 18 (23%) were symptomatic. Patients who had a large amount of effusion were more likely to be symptomatic than those with only a small to moderate amount (47.4% v 15.5%, p = 0.01). The mean (SD) onset of pericardial effusion was 11 (7) days after surgery, with 97% (75 of 77) of cases being diagnosed on or before day 28 after surgery. The prevalence of effusion after Fontan-type procedures (60%, 6 of 10) was significantly higher than that after other types of cardiac surgery: repair of left to right shunts (22.1%, 43 of 195), repair of lesions with right ventricular outflow tract obstruction (22.6%, 19 of 84), arterial switch operation (6.7%, 1 of 15), and miscellaneous procedures (25%, 8 of 32) (p = 0.037). Univariate analyses showed that female patients (p = 0.009) and those receiving warfarin (p = 0.002) had increased risk of postoperative pericardial effusion. A greater pericardial drain output in the first four hours after surgery also tended to be significant (p = 0.056). Multivariate logistic regression similarly identified warfarin treatment (beta = 1.73, p = 0.009) and female sex (beta for male = -0.63, p = 0.037) as significant determinants. CONCLUSIONS: Pericardial effusion occurs commonly after open heart surgery for congenital heart disease. Serial echocardiographic monitoring up to 28 days postoperatively is indicated in selected high risk patients such as those with symptoms of postpericardiotomy syndrome and those given warfarin.

Outcome of infants with right atrial isomerism: is prognosis better with normal pulmonary venous drainage?

OBJECTIVE: To compare the outcome of infants and children who have right atrial isomerism and normal pulmonary venous drainage with those who have anomalous drainage, and to determine factors associated with poor outcome. DESIGN AND PATIENTS: Retrospective review of management and outcome of 116 infants and children determined to have right atrial isomerism between January 1980 and December 2000. SETTING: Tertiary paediatric cardiac centre. RESULTS: The 116 patients presented at a median of one day (range 1 day to 3.7 years) with cyanosis in the majority (96%). No interventions were planned in 31 (27%) patients, all of whom died. The early surgical mortality for pulmonary venous repair was 25% (2 of 8), Fontan procedure 26% (5 of 19), cavopulmonary shunting 7.7% (1 of 13), and systemic pulmonary arterial shunt insertion 1.9% (1 of 53). Late mortality was related to infection (n = 10), sudden death of unknown aetiology (n = 7, 5 with history of arrhythmia), and documented arrhythmia (n = 1). Patients with obstructed anomalous pulmonary venous drainage had the worst survival (p < 0.001). The mean (SEM) survival estimates for those with normal pulmonary venous drainage at 1, 5, 10, and 15 years was 81 (5.3)%, 67 (6.6)%, 60 (7.8)%, and 43 (12)%, respectively, similar to those for patients with non-obstructed anomalous drainage (p = 0.06). Independent risk factors for mortality included pulmonary venous obstruction (relative risk 3.8, p = 0.001) and a single ventricle (relative risk 2.9, p = 0.016). An analysis of only patients with normal pulmonary venous drainage identified no risk factors for mortality. CONCLUSIONS: The long term outcome of infants and children with right atrial isomerism in association with a normal pulmonary venous drainage remains unfavourable. Sepsis and sudden death that may potentially be related to cardiac arrhythmia are major causes of late mortality.

Analysis of indications for surgical closure of subarterial ventricular septal defect without associated aortic cusp prolapse and aortic regurgitation.

Subarterial ventricular septal defect (VSD) is relatively common in Orientals. We reviewed the outcome of 214 patients (137 males) who were followed for 8.6 +/- 5.2 years (range 0.1 to 24.3) and addressed the issue regarding the necessity and optimum timing of closing subarterial defects before development of aortic valve deformities. Demographic data, transthoracic and transesophageal echocardiographic findings, cardiac catheterization results, and operative findings were reviewed. Kaplan-Meier actuarial analysis was performed to assess the development of aortic valve complications over time. Seventy-five patients with heart failure and pulmonary hypertension underwent surgical closure of VSD at the age of 2.4 +/- 2.9 years. No patient had aortic cusp prolapse before operation and none developed aortic cusp prolapse or aortic regurgitation (AR) on follow-up. In contrast, of the 139 asymptomatic patients managed conservatively, 102 (73%) developed aortic cusp prolapse, 78% of whom (80 of 102) developed AR. The prevalence of aortic cusp prolapse and AR at 1, 5, 10, and 15 years old was 8%, 30%, 64%, and 83%, and 3%, 24%, 45%, and 64%, respectively. Significant prolapse or AR prompted surgical closure of VSD with (n = 22) or without (n = 26) valvoplasty in 48 of 102 patients (47%). The size of the VSD was significantly larger in patients with heart failure (9.6 +/- 3.3 mm) or aortic cusp prolapse (11.7 +/- 4.1 mm) compared with those without heart failure (4.5 +/- 1.4 mm, p <0.001). All patients with aortic cusp prolapse and all but 1 with heart failure had a defect size of > or =5 mm. In conclusion, subarterial VSD of > or =5 mm should be closed as early as possible to prevent development of aortic cusp prolapse and AR. Asymptomatic patients with small defects <5 mm could be managed conservatively.

Activation-dependent changes in receptor distribution and dendritic morphology in hippocampal neurons expressing P2X2-green fluorescent protein receptors.

ATP-gated P2X(2) receptors are widely expressed in neurons, but the cellular effects of receptor activation are unclear. We engineered functional green fluorescent protein (GFP)-tagged P2X(2) receptors and expressed them in embryonic hippocampal neurons, and report an approach to determining functional and total receptor pool sizes in living cells. ATP application to dendrites caused receptor redistribution and the formation of varicose hot spots of higher P2X(2)-GFP receptor density. Redistribution in dendrites was accompanied by an activation-dependent enhancement of the ATP-evoked current. Substate-specific mutant T18A P2X(2)-GFP receptors showed no redistribution or activation-dependent enhancement of the ATP-evoked current. Thus fluorescent P2X(2)-GFP receptors function normally, can be quantified, and reveal the dynamics of P2X(2) receptor distribution on the seconds time scale.

Coronary artery fistulas: long-term results of surgical correction.

BACKGROUND: Opinions vary as to whether operation should be offered patients with coronary artery fistula, particularly to those who are asymptomatic. Published studies lacked long-term follow-up data. METHODS: We studied 41 patients with coronary artery fistula operated in our unit in the past 30 years with restudies including coronary angiograms in those who agreed to the investigation. RESULTS: There was no operative mortality and operative morbidity was low. The mean duration of follow-up was 9.1 years and 96.9% of the patients were asymptomatic. Twenty-one patients had a coronary angiogram. The native coronary artery either remained dilated and tortuous, or more frequently had thromboses with a short proximal stump. (None of these patients had evidence of myocardial ischemia.) Four patients had demonstrable recurrence fistula but without hemodynamic disturbance. CONCLUSIONS: We advocate operation for all patients with coronary artery fistulas and demonstrable shunting in view of minimal operative risks. Small asymptomatic fistulas without demonstrable shunting should be left alone. The relatively high incidence of residual or recurrent fistula makes long-term follow-up mandatory.

Single-molecule measurements calibrate green fluorescent protein surface densities on transparent beads for use with 'knock-in' animals and other expression systems.

Quantitative aspects of synaptic transmission can be studied by inserting green fluorescent protein (GFP) moieties into the genes encoding membrane proteins. To provide calibrations for measurements on synapses expressing such proteins, we developed methods to quantify histidine-tagged GFP molecules (His6-GFP) bound to Ni-NTA moieties on transparent beads (80-120 microm diameter) over a density range comprising nearly four orders of magnitude (to 30000 GFP/microm2). The procedures employ commonly available Hg lamps, fluorescent microscopes, and CCD cameras. Two independent routes are employed: (1) single-molecule fluorescence measurements are made at the lowest GFP densities, providing an absolute calibration for macroscopic signals at higher GFP densities; (2) known numbers of His6-GFP molecules are coupled quantitatively to the beads. Each of the two independent routes provides linear data over the measured density range, and the two independent methods agree with root mean square (rms) deviation of 11-21% over this range. These satisfactory results are obtained on two separate microscope systems. The data can be corrected for bleaching rates, which are linear with light intensity and become appreciable at intensities > approximately 1 W/cm2. If a suitable GFP-tagged protein can be chosen and incorporated into a 'knock-in' animal, the density of the protein can be measured with an absolute accuracy on the order of 20%.