[Efficacy of arteriovenous argatroban versus heparin flush anticoagulation after cardiovascular surgery]

Objective: To compare the effects of arteriovenous argatroban and heparin flushes on platelet count and assess the occurrence of heparin-induced thrombocytopenia (HIT) and other complications in patients undergoing cardiovascular surgeries. Methods: A single-center, prospective randomized control study was conducted. Patients who underwent cardiovascular surgery at Fuwai Hospital, Chinese Academy of Medical Sciences from March to December 2019 were randomly divided into the argatroban group (250 ml normal saline plus 2.5 mg of argatroban) and the heparin group (250 ml normal saline plus 10 mg of heparin). Platelet count, hemorrhage, and thrombosis were assessed. The 4T scores of HIT, the incidences of HIT and other complications were also evaluated. Results: A total of 491 patients (307 males and 184 females) were included in the study, with a mean age of (52.3±13.7) years. There were 245 cases in the argatroban group and 246 cases in the heparin group, respectively. There was no statistically significant difference in the preoperative platelet count between the argatroban and heparin groups [198.0 (161.0, 248.0)×10⁹/L vs 194.0 (157.2, 243.8)×10⁹/L, P=0.498]. Likewise, there were no statistically significant differences in the platelet count between the argatroban and heparin groups at 12 h, 1 day, and 5 days after operation [127.0 (100.0, 154.0)×10⁹/L vs 121.5 (90.2, 149.0)×10⁹/L, 126.0 (97.0, 162.0)×10⁹/L vs 123.5 (88.0, 151.0)×10⁹/L, 168.0 (130.0, 215.0) ×10⁹/L vs 161.0 (101.0, 210.5)×10⁹/L] (repeated measures ANOVA between groups: F=3.327, P=0.069; time comparison: F=532.523, P<0.001; time interaction between groups: F=0.675, P=0.512). The proportion of 4T scores of medium and high scores (≥4)[9.8% (24/245) vs 10.6% (26/246), P=0.777] and incidence of HIT antibody positive [1.63% (4/245) vs 1.63% (4/246), P=0.726] were similar between argatroban group and the heparin group. Mechanical ventilation time was shorter in the argatroban group than that in the heparin group [13.0 (11.0, 21.0) vs 15.5 (12.0, 21.0) h, P=0.020]. Conclusion: Compared with heparin, routine management with argatroban for arteriovenous flush in patients undergoing cardiovascular surgery does not affect the HIT incidence.

[Association of thrombocytopenia with mortality after surgery in patients with Standford type A aortic dissection]

Objective: To evaluate the association of thromboytopenia with mortality of Standford type A aortic dissection after cardiopulmonary bypass surgery. Methods: Total of 498 patients with Standford type A aortic dissection after surgery in Fuwai Hospital of the Chinese Academy of Medical Sciences from May 2017 to December 2018 were collected retrospectively. There were 350 males and 148 females, with a mean age of (51.7±12.0) years. The patients were divided into thrombocytopenia group (platelet count<75×10¹⁵/L, n=178) and normal platelet group (platelet count≥75×10¹⁵/L, n=320) according to the lowest platelet count within 72 hours after surgery. The perioperative in-hospital mortality and related complications were calculated by univariate and multivariate logistic regression analysis. The primary endpoint was in-hospital mortality, and the secondary endpoints included secondary thoracotomy, pneumonia, postoperative continuous renal replacement therapy, paraplegia, heart failure, length of hospital stay and intensive care unit (ICU) stay time. Results: The morbidity of thrombocytopenia after Standford type A aortic dissection surgery was 35.7% (178/498). Univariate logistic regression analysis showed that postoperative thrombocytopenia was significantly associated with in-hospital mortality and 7 secondary endpoints (P<0.05). Multivariate logistic regression analysis showed thrombocytopenia after aortic dissection surgery was significantly associated with increased postoperative mortality (OR=12.57, 95%CI: 2.26-69.93, P=0.004), secondary thoracotomy (OR=6.21, 95%CI: 1.31-29.46, P=0.022), continuous renal replacement therapy (OR=7.51, 95%CI: 2.53-22.34, P<0.001), paraplegia (OR=23.99, 95%CI: 1.47-392.21, P=0.026), heart failure (OR=4.71, 95%CI: 1.19-18.62, P=0.027) and longer ICU stay time (OR=1.86, 95%CI: 1.11-3.12, P=0.019). Conclusions: Thrombocytopenia after Standford type A aortic dissection after cardiopulmonary bypass surgery (the lowest platelet count within 72 hours) is strongly associated with postoperative in-hospital mortality. Trying to avoid the factors related to thrombocytopenia can prevent more complications at the same time.

[Early outcome of valve sparing aortic root replacement with partial upper sternotomy]

Objective: To examine the early outcome of valve sparing aortic root replacement with reimplantation technique (David procedure) with partial upper sternotomy. Methods: From April 2016 to April 2020, 31 patients underwent valve sparing aortic root replacement under partial upper sternotomy at Vascular Surgery Center, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College. There were 28 males and 3 females, aging (44±13) years (range: 11 to 65 years). Preoperative aortic regurgitation was found greater than moderate in 15 patients, moderate in 6 patients and less than moderate in 10 patients. The diameter of aortic annulus was (26±3) mm (range: 21 to 34 mm), the diameter of aortic sinus was (51±6) mm (range: 41 to 68 mm), the diameter of ascending aorta was (43±8) mm (range: 26 to 62 mm). The preoperative ejection fraction was (65±4) % (range: 59% to 72%) and left ventricular end-diastolic diameter was (55±6) mm (range: 42 to 68 mm). All cases were treated with David Ⅰ procedure, including simple David procedure in 26 patients, David+ascending aorta and partial aortic arch replacement in 3 patients, David+thoracic endovascular aortic repair in 1 patient, David+stent elephant trunk implantation in 1 patient. Results: The operation time, cardiopulmonary bypass time and aortic cross-clamping time were (330±58) minutes (range: 214 to 481 minutes), (138±23) minutes (range: 106 to 192 minutes) and (108±17) minutes (range: 82 to 154 minutes), respectively. There were no death and serious complications (stroke, myocardial infarction, renal insufficiency, severe infection, etc.). The postoperative drainage volume within 24 hours was (314±145) ml (range: 130 to 830 ml). The intubation time was (14±3) hours (range: 8 to 21 hours), and the ICU time was (M(Q_R)) 2.1(1.5) days (range: 1.0 to 5.0 days). Eight patients had no blood transfusion, the proportion of red blood cell use was 9.7% (3/31), plasma use was 22.6% (7/31), and platelet use was 71.0% (22/31). The postoperative left ventricular ejection fraction was (62±4)% (range: 54% to 69%), and left ventricular end-diastolic diameter was (48±4) mm (range: 39 to 56 mm). After operation, aortic regurgitation was significantly improved, with no more than moderate regurgitation, small to moderate regurgitation in 3 patients, minor regurgitation in 3 patients, micro regurgitation in 12 patients and no regurgitation in 13 patients. The follow-up period was 3.5(6.1) months (range: 2.0 to 39.0 months). Echocardiographic follow-up data were obtained in 26 cases, including moderate regurgitation in 1 patient, small to moderate regurgitation in 9 patients, minor regurgitation in 5 patients, micro regurgitation in 6 patients and no regurgitation in 5 patients. There were no major adverse cardiovascular events and aortic events during the follow-up period. No patient was reoperated for aortic regurgitation. Conclusion: Valve sparing aortic root replacement under partial upper sternotomy is safe and feasible, and the early result is satisfactory.

Cone photoreceptor reflectance variation in the northern tree shrew and thirteen-lined ground squirrel

In vivo images of human cone photoreceptors have been shown to vary in their reflectance both spatially and temporally. While it is generally accepted that the unique anatomy and physiology of the photoreceptors themselves drives this behavior, the exact mechanisms have not been fully elucidated as most studies on these phenomena have been limited to the human retina. Unlike humans, animal models offer the ability to experimentally manipulate the retina and perform direct in vivo and ex vivo comparisons. The thirteen-lined ground squirrel and northern tree shrew are two emerging animal models being used in vision research. Both models feature cone-dominant retinas, overcoming a key limitation of traditional rodent models. Additionally, each possesses unique but well-documented anatomical differences in cone structure compared to human cones, which can be leveraged to further constrain theoretical models of light propagation within photoreceptors. Here we sought to characterize the spatial and temporal reflectance behavior of cones in these species. Adaptive optics scanning light ophthalmoscopy (AOSLO) was used to non-invasively image the photoreceptors of both species at 5 to 10 min intervals over the span of 18 to 25 min. The reflectance of individual cone photoreceptors was measured over time, and images at individual time points were used to assess the variability of cone reflectance across the cone mosaic. Variability in spatial and temporal photoreceptor reflectance was observed in both species, with similar behavior to that seen in human AOSLO images. Despite the unique cone structure in these animals, these data suggest a common origin of photoreceptor reflectance behavior across species. Such data may help constrain models of the cellular origins of photoreceptor reflectance signals. These animal models provide an experimental platform to further explore the morphological origins of light capture and propagation.

[Application of sutureless integrated stented graft in patients with aortic dissection]

Objective: To preliminarily investigate effectiveness and safety of sutureless integrated stented graft (SIS graft) on aortic dissection patients undergoing surgeries. Methods: In October 2019, 2 patients with aortic dissection were treated by SIS graft in Shenzhen Fuwai Hospital. Data of the operations and follow-up were recorded. Results: Patient 1 (male, 42 years old) was treated with aortic sinus repair, ascending aortic replacement, total arch replacement combined with frozen elephant trunk implantation. Time of cardiopulmonary bypass and circulatory arrest was 81 minutes and 9.5 minutes,respectively. The lowest nasopharynx temperature was 27.3 ℃. This patient was followed up for 10 months and no postoperative complication was found. Six-month postoperative aortic CT angiography (CTA) revealed SIS graft was patent and no anastomosis fistula or stent leakage occurred. True lumen of stented area was full-filled and false lumen disappeared. Incomplete false lumen thrombosis was seen in un-stented thoracic aorta, but no progressive aortic enlargement appeared. Patient 2 (male, 61 years old) was treated with ascending aortic replacement, ascending aorta to right femoral artery bypass graft, total arch replacement combined with frozen elephant trunk implantation. Time of cardiopulmonary bypass and circulatory arrest was 77 minutes and 7 minutes,respectively. The lowest nasopharynx temperature was 27.3 ℃. This patient was also followed up for 10 months and was free of postoperative complications. Six-month postoperative aortic CTA revealed SIS graft was patent and there was no anastomosis fistula or stent leakage. Perfusion of true lumen in thoracic aorta and branches of abdominal aorta improved significantly and complete false lumen thrombosis could be seen in thoracic aorta. Progressive aortic enlargement was not detected. Conclusion: Application of SIS graft can reduce circulatory arrest time and avoid deep hypothermia, which will decrease risks of postoperative complications, and this graft can simplify surgery procedure. However, further clinical trial for effectiveness and safety of SIS graft should be applied.

[Overview of multi-center registry of aortic dissection]

Aortic dissection is a life-threatening cardiovascular disease. Multi-center registration databases for aortic dissection have been established in many countries. The International Registry of Acute Aortic Dissection has produced a number of research results, which had a significant impact on the diagnosis and treatment of aortic dissection worldwide. The Society for Thoracic Surgeons Adult Cardiac Surgery Database summarizes perioperative data on aortic dissection. German Registry for Acute Aortic Dissection Type A has made remarkable achievements in the neurological protection and organ perfusion of type A aortic dissection. The Nordic Consortium for Acute Type A Aortic Dissection provides guidelines for perioperative administration of aortic dissection. However, the first Registry of Aortic Dissection in China (Sino-RAD) has not reported any new aortic dissection data in the past five years, although it has proposed a number of pathogenic characteristics of Chinese people. Therefore, it is necessary to establish our own aortic dissection database.

[Correlation between of aortic dissection onset and climate change]

Objective: To explore the relationship between the incidence of aortic dissection and climate change. Methods: The characteristics of 345 acute aortic dissection patients came from Beijing in Department of Vascular Surgery, Fu Wai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences, Peking Union Medical College from January 2005 to December 2015 were analyzed, retrospectively. There were 266 male and 79 female patients with a mean age of (49±12) years. There were 209 cases of Stanford type A aortic dissection, and 136 cases of type B. According to Fuwai aortic dissection classification: type A 8 cases, type B 95 cases, type Cp 13 cases, type Ct 187 cases, type Cd 40 cases, type D 2 cases. Meanwhile, monthly maximum temperature, minimum temperature, average temperature, average pressure, amount of rainfall, sunshine, relative humidity and other meteorological data were collected. Rank-sum test was used to analyze the difference of onset of aortic dissection in different seasons and months. Generalized additive models were implied to explore climate change and the onset of aortic dissection. Results: The onset of aortic dissection was related to season. Winter had higher morbidity compared to summer (M(Q(R)): 3(2) vs. 2(2), Z=1.97, P=0.05). The occurrence of aortic dissection was associated with month.December had the largest quantity, July had the least (2(3) vs. 2(1), Z=2.42, P=0.02). The mean temperature was statistically significant for indicating the change of aortic dissection onset. It meaned that onset probability was increased with the decrease of temperature (RR=1.01, 95%CI: 1.00 to 1.02, P=0.04). Conclusions: The onset of aortic dissection had something to do with season and month. The incidence of aortic dissection increases with temperature decreases.

Clinical decision making and preference assessment for individuals with intellectual and developmental disabilities

Individuals with intellectual or developmental disabilities are able to reliably express their likes and dislikes through direct preference assessment. Preferred items tend to function as rewards and can therefore be used to facilitate the acquisition of new skills and promote task engagement. A number of preference assessment methods are available and selecting the appropriate method is crucial to provide reliable and meaningful results. The authors conducted a systematic review of the preference assessment literature, and developed an evidence-informed, decision-making model to guide practitioners in the selection of preference assessment methods for a given assessment scenario. The proposed decision-making model could be a useful tool to increase the usability and uptake of preference assessment methodology in applied settings.

The hierarchical relationship between several visual and auditory discriminations and three verbal operants among individuals with developmental disabilities

This study examined the relationship between performance on the Assessment of Basic Learning Abilities test (ABLA), two auditory matching tasks, and a test of echoics, tacts, and mands with persons with developmental disabilities. It was found that discrimination skill (visual, auditory-visual, and auditory-auditory discriminations) was a better predictor of performance on verbal operant assessments than level of functioning based on diagnosis. The results showed high test-retest reliability for the test of verbal operants and no hierarchical relationship was found among the three verbal operants. The results suggest that the ABLA Level 6 might be a possible bridging task for teaching echoics, tacts, and mands. Further research is needed to ascertain the relation between the auditory matching tasks and the verbal operants.

Correlates of age at diagnosis of autism spectrum disorders in six Canadian regions

INTRODUCTION

Early identification of autism spectrum disorders (ASD) is important, since earlier exposure to behavioural intervention programs may result in better outcomes for the child. Moreover, it allows families timely access to other treatments and supports.

METHODS

Using generalized linear modeling, we examined the association between child and family characteristics and the age at which 2180 children were diagnosed with ASD between 1997 and 2005 in six Canadian regions.

RESULTS

A diagnosis of pervasive developmental disorder-not otherwise specified (PDD-NOS) or Asperger syndrome, rural residence, diagnosis in more recent years, and foreign birthplace were associated with a later age at diagnosis. Children who are visible minorities or who have siblings with ASD were more likely to be diagnosed earlier. Collectively, these factors explained little of the variation in age at diagnosis, however.

CONCLUSION

While it is encouraging that ethnocultural identity, neighbourhood income, urban or rural residence, and sex of the child were not major contributors to disparities in the age when children were identified with ASD, more work is needed to determine what does account for the differences observed. Regional variations in the impact of several factors suggest that aggregating data may not be an optimal strategy if the findings are meant to inform policy and clinical practice at the local level.

Teaching children with autism spectrum disorder to mand for information using "which?"

We examined a procedure consisting of a preference assessment, prompting, contrived conditioned establishing operations, and consequences for correct and incorrect responses for teaching children with autism to mand "which?" We used a modified multiple baseline design across 3 participants. All the children learned to mand "which?" Generalization occurred to the natural environment, to a novel activity, and to a novel container; the results were maintained over time.

On the relation between reinforcer efficacy and preference

Most research on stimulus preference and reinforcer assessment involves a preference assessment that is followed by a reinforcer assessment. Typically, the most and least preferred stimuli are tested as reinforcers. In the current study, we first quantified the reinforcing efficacies of six food items and then assessed relative preference for each item. Relative preference ranking and reinforcer efficacies showed almost perfect concordance for 1 participant and partial concordance for the other. Discordance tended to occur with the weakest reinforcers.

Age at diagnosis of autism spectrum disorders in four regions of Canada

OBJECTIVES

Early diagnosis of autism spectrum disorders ("autism") may lead to better treatment outcomes, reduces the stress parents experience when they do not understand the reasons for their child's behaviour, and empowers parents to make choices such as seeking genetic counseling. We examined the age at which Canadian children are diagnosed with autism, and analyzed whether there are geographic or temporal variations or differences by sex or diagnostic subtype.

METHODS

As part of an autism surveillance program, in 2002/2003 we began collecting information on children with autism in Manitoba, Southeastern Ontario, Prince Edward Island, and Newfoundland and Labrador. For the analysis presented in this paper, we included children identified for our surveillance program who were diagnosed between 1997 and 2005 (n = 769).

RESULTS

We found significant inter-regional differences in age at diagnosis, with Newfoundland and Labrador having the lowest median age at diagnosis (39.0 months) and Southeastern Ontario the highest (55.0 months). Diagnostic subtype was significantly associated with age at diagnosis in all regions. Southeastern Ontario was the only region where the overall age at diagnosis increased over time (p = 0.004), although in Manitoba the age at which children were diagnosed with PDD-NOS also increased significantly over the study period (p = 0.021).

CONCLUSIONS

Our findings demonstrate that there are geographic differences and other sources of variation in the age at which Canadian children are diagnosed with autism. Further study is warranted to understand the factors contributing to these differences. Such research would inform best practices for early detection and timely access to treatment.

Discrimination Skills Predict Effective Preference Assessment Methods for Adults with Developmental Disabilities

We examined the relationship between three discrimination skills (visual, visual matching-to-sample, and auditory-visual) and four stimulus modalities (object, picture, spoken, and video) in assessing preferences of leisure activities for 7 adults with developmental disabilities. Three discrimination skills were measured using the Assessment of Basic Learning Abilities Test. Three participants mastered a visual discrimination task, but not visual matching-to-sample and auditory-visual discriminations; two participants mastered visual and visual matching-to-sample discriminations, but not auditory-visual discrimination, and two participants showed all three discriminations. The most and least preferred activities, identified through paired-stimulus preference assessment using objects, were presented to each participant in each of the four modalities using a reversal design. The results showed that (1) participants with visual discrimination alone showed a preference for their preferred activities in the object modality only; (2) those with visual and visual matching-to-sample discriminations, but not auditory-visual discrimination, showed a preference for their preferred activities in the object but not in the spoken modality, and mixed results in the pictorial and video modalities; and (3) those with all three discriminations showed a preference for their preferred activities in all four modalities. These results provide partial replications of previous findings on the relationship between discriminations and object, pictorial, and spoken modalities, and extend previous research to include video stimuli.

The assessment of basic learning abilities test for predicting learning of persons with intellectual disabilities: a review

The Assessment of Basic Learning Abilities (ABLA) Test uses standard prompting and reinforcement procedures to assess the ease or difficulty with which a testee is able to learn a simple imitation and five two-choice discriminations. The authors review studies that have examined performance of participants with developmental disabilities (DD) on the ABLA test to predict (a) performance on a variety of simple imitations and two-choice discriminations, (b) performance on three-choice and four-choice discriminations, (c) the relative efficacy of three presentation modes (objects vs. photographs vs. verbal descriptions) for assessing preferences, (d) compliance of adults with DD and children with and without DD, and (e) participants' ability to learn to respond to the spoken names of pictures of common objects. Across all five types of studies, the predictive validity of the ABLA test has been very high.

Passive and Active Approach Responses in Preference Assessment for Children With Profound Multiple Disabilities and Minimal Movement

We assessed the activity preferences of three children with profound multiple disabilities and minimal movement using a single stimulus presentation procedure. We recorded active approach, passive approach, and rejection responses on each trial during the assessments. Active approach included reaching for, touching, or manipulating the stimulus. Passive approach included looking at or orienting toward the stimulus and happiness indicators such as smiling. Active approaches and rejection responses were infrequent, but preference hierarchies based on passive approaches emerged for all three children. Two children were available for reinforcer testing after the preference assessments. The identified high preference activities based on passive approach responses maintained higher rates of switch pressing than the low preference activities for one child and maintained approximately the same rates of switch pressing for the second child.

Predictors of depressive symptoms in primary caregivers of young children with or at risk for developmental delay

BACKGROUND

Despite extensive research with families raising children with or at risk for developmental delay (DD), it is not clear whether primary caregivers of these children are at increased risk for depressive symptoms. Discrepant findings in the literature may be owing to heterogeneity of child problems. More research is needed on child, parent and family variables that may increase risk for, or resilience to, caregiver depressive symptoms. Some studies have found that parental resources (e.g. social support and coping strategies) may buffer the effects of parental distress, while other studies have highlighted the role of parental self-efficacy.

METHODS

We examined Beck Depression Inventory (BDI) scores in 178 primary caregivers (mainly biological mothers) who had 2-year-old children with or at risk for DD owing to: (a) low birthweight, prematurity or multiple birth (n = 58), (b) other known reasons (e.g. Down syndrome, spina bifida) (n = 67), or (c) unknown reasons (n = 69).

RESULTS

We found that 20% (n = 35) of the caregivers scored above the BDI clinical cut-off for depression. Analysis of variance revealed that caregivers with elevated BDI scores had higher child behaviour problem and escape-avoidance coping scores, and lower social support and parent self-efficacy, compared with caregivers without depressive symptoms. Caregivers with children who had DD for unknown reasons had higher BDI scores than caregivers of the other two groups of children. Regression analyses showed that child behaviour problems, escape-avoidance coping strategies and social support predicted caregiver BDI scores, but caregiver self-efficacy only did so when entered independently of social support. Only social support mediated and (marginally) moderated the relationship between child behaviour problems and caregiver depressive symptoms.

CONCLUSIONS

These findings suggest that early intervention programmes should carefully consider the interaction of child characteristics (e.g. Diagnosis and behaviour problems), caregiver resources (e.g. coping strategies and social support), and parental mental health and mood when planning and tailoring services for families of children with or at risk for DD.

Predicting learning ability of people with intellectual disabilities: assessment of basic learning abilities test versus caregivers' predictions

Two sets of predictions were compared concerning the ability of 20 adults with profound, severe, or moderate intellectual disabilities to learn 15 everyday tasks. Predictions were made by caregivers who had worked with the participants for a minimum of 24 months and consideration of participant performance on the Assessment of Basic Learning Abilities (ABLA) test. Standardized training procedures were used to attempt to teach each task to each participant until a pass or fail criterion was met. Ninety-four percent of predictions based on ABLA performance were confirmed, and the ABLA was significantly more accurate for predicting client performance than were the caregivers. The utility of these results is discussed.

Therapeutic Potential of Human Umbilical Cord–Derived Stem Cells in Ischemic Diseases

Recent advances suggest human umbilical cord is a new source for stem cells. Our laboratory has established a method to readily isolate and expand stem cells from human umbilical cord tissues. The aim of this study was to investigate the therapeutic potential of human umbilical cord-derived stem (UCDS) cells in ischemic diseases. The UCDS cells were characterized by flow cytometry and differentiation into osteogenic and adipogenic cells. Unilateral hind limb ischemia was surgically induced by femoral artery ligation in nude mice. The animals were intramuscularly injected with 10(6) UCDS cells or control phosphate-buffered saline. Blood perfusion of ischemic limbs was detected by laser Doppler perfusion imaging. Transplantation of UCDS cells to the ischemic limbs of nude mice significantly improved the blood flow to the affected limbs. Thus, transplantation of UCDS cells may potentially be a promising treatment for human ischemic diseases.

Predicting Optimal Preference Assessment Methods for Individuals with Developmental Disabilities

The single-stimulus (SS) preference assessment procedure has been described as more appropriate than the paired stimulus (PS) procedure for "lower functioning" individuals, but this guideline's vagueness limits its usefulness. We administered the SS and PS preference assessment procedures with food items to seven individuals with severe or profound developmental disabilities who scored at level 2 of the Assessment of Basic Learning Abilities (ABLA) and seven who scored at ABLA level 3. Thirteen of the 14 participants also received these assessments (PS and SS), with non-food items. The two procedures were about equally effective for both groups, and with both types of stimuli, although the PS procedure produced more refined preference hierarchies. Most participants showed moderate to high correlations in preference scores between the two procedures for both food and non-food items. These results suggest that, for individuals who score at either ABLA level 2 or ABLA level 3, the SS and the PS procedures are equally likely to identify preferred stimuli.

Factors affecting parenting stress among biologically vulnerable toddlers

Parenting a child with, or at risk for, a developmental delay or disability can be stressful. Abidin's parenting stress model was used as a framework to examine how several maternal, child, and family factors predict parent stress outcomes. Stepwise regression models revealed that maternal and child factors were significant contributors to parenting stress. However, family factors (income and family functioning) were not retained. Parenting stress was lower when child (cognitive and adaptive ability) and maternal (depression and child care competence) characteristics were more positive. Child cognitive ability was a strong contributor to total parenting stress and two parenting stress subscales. Findings suggest that these parents need stress lowering interventions such as supportive child care, respite relief, and a child behaviour-focused program.

SENSITIVITY OF PASSIVE APPROACH DURING PREFERENCE AND REINFORCER ASSESSMENTS FOR CHILDREN WITH SEVERE AND PROFOUND INTELLECTUAL DISABILITIES AND MINIMAL MOVEMENT

We evaluated the use of passive approach to assess preferences of two children, with severe and profound intellectual disabilities. Both children had physical challenges and exhibited minimal physical movement. We also compared the relative reinforcing effects of the identified high and low preference stimuli for a switch pressing response, and for a more passive looking response. High and low preference stimuli were identified for both children. Moreover, the high preference stimulus maintained higher rates of responding than the low preference stimulus for both children for the passive looking response, but not for switch pressing. The study extended the use of passive approach to assess preferences and identified the choice of target response as a potential limiting factor during reinforcer tests for these children.

On Choice, Preference, and Preference for Choice

In this paper, we examine several common everyday meanings of choice, propose behavioral definitions of choice, choosing, and preference, and recommend ways for behavioral researchers to talk consistently about these concepts. We also examine the kinds of performance in the contexts of various procedures that might be appropriately described as a preference for choice. In our view, the most appropriate procedure for demonstrating preference for choice as a consequence is a concurrent chains method, in which choice is a reinforcer for an approach response. The single-stimulus procedure, however, is more appropriate for demonstrating preference for choice as an antecedent.

Predicting the Relative Efficacy of Verbal, Pictorial, and Tangible Stimuli for Assessing Preferences of Leisure Activities

We measured the relationships between choice stimulus modalities and three basic discriminations (visual, visual matching-to-sample, and auditory-visual) using the Assessment of Basic Learning Abilities test. Participants were 9 adults who had moderate to profound developmental disabilities. Their most and least preferred leisure activities, identified by prior preference assessments, were presented using choice stimuli in three modalities (tangibles, pictures, and verbal descriptions) in an alternating-treatments design. For 8 of the 9 participants, discrimination skills predicted the selections of choice stimuli associated with their preferred activities. The results suggest that choice stimulus modalities in preference assessment of leisure activities need to be matched to the discrimination skills of persons with developmental disabilities.

Choice, Degree of Preference, and Happiness Indices with Persons with Intellectual Disabilities: A Surprising Finding

Two persons with severe intellectual disabilities and two persons with profound intellectual disabilities were repeatedly presented with five different pairs of food items. The five pairs of items represented different degrees of preference, from highest to lowest. Happiness indices were monitored from the time that a pair of items was presented until a choice was made. Surprisingly, participants showed very few happiness indices throughout the study, and degree of preference had very little effect on frequency of happiness indices. Questions are raised regarding choice opportunities and indices of happiness as indicators of quality of life.

Visual–Visual Nonidentity Matching Assessment: A Worthwhile Addition to the Assessment of Basic Learning Abilities Test

The Assessment of Basic Learning Abilities test (ABLA) is a useful tool for choosing appropriate training tasks for persons with developmental disabilities. This test assesses the ease or difficulty with which persons are able to learn six hierarchically positioned discrimination tasks. A visual-visual nonidentity matching prototype task was examined to assess its (a). relation to the ABLA hierarchy, (b). predictive validity, and (c). test-retest reliability. Results from 23 participants with developmental disabilities suggest that visual-visual nonidentity matching is a worthwhile addition to the ABLA test and is positioned in the ABLA hierarchy above Level 4 (visual-visual identity matching) and below Level 6 (auditory-visual discrimination). The prototype visual-visual nonidentity matching task also demonstrated high predictive validity and test-retest reliability.

Effects of Choice of Work Tasks on On-Task, Aberrant, Happiness and Unhappiness Behaviours of Persons with Developmental Disabilities

Effects of choice versus no choice of work tasks on work performance, inappropriate behaviours, happiness and unhappiness indices were examined in three studies. Study 1 examined the effects of a choice between a high and a low preference task, versus the assignment of the high preference task. Study 2 was similar to Study 1 except that the tasks in the choice condition were equally and moderately preferred. Study 3 was conducted by the participants' instructors in their natural work settings. A total of five participants were involved across the three studies. Very few differences were found under the choice and no-choice conditions. More research is needed to examine the role of reinforcement history in establishing stimulus control effects of choice.

Tangibles, Pictures, and Verbal Descriptions: Which Should Be Used in Choice Presentations?

Little research has examined how stimulus modalities influence choice responding. Should choice alternatives be presented using tangibles, pictures, or verbal descriptions? How should caregivers decide which modality to use? We have completed several studies to examine how discrimination skills, as measured by the Assessment of Basic Learning Abilities test, interact with choice stimulus modalities to influence responding. Our results suggest that for persons with developmental disabilities with limited or no communication skills, the ability to make simple visual, visual matching to sample, and auditory-visual discriminations should be the prime determinant of stimulus modalities in choice presentation and preference assessment.

Endogenous nitric oxide inhibits neutrophil adherence to lung epithelial cells to modulate interleukin-8 release

To investigate the effect of neutrophil adherence to epithelial cells on the release of interleukin 8 (IL-8), we measured neutrophil adherence in the presence or absence of IFN-gamma+TNF-alpha+IL-1beta (cytomix) stimulation on cultured A549 epithelial cells. The extent of neutrophil adherence to A549 epithelial cells was measured and the concomitant production of IL-8 and nitrite were assayed. The roles of adhesion molecules and nitrite in modulation of neutrophil adherence were examined by pretreatment with oversaturating ICAM-1 blocking antibody and L-NAME (1 mM), respectively. There was a time-dependent spontaneous and cytomix-induced release of IL-8 from epithelial cells, as well as a time-dependent increase in the magnitude of neutrophil adherence to epithelial cells. Stimulation of epithelial cells with cytomix induced a further increase in neutrophil adherence. Pretreatment with oversaturated ICAM-1 monoclonal antibody inhibited neutrophil adherence with or without cytomix stimulation. The inhibition of neutrophil adherence to epithelial cells with ICAM-1 monoclonal antibody or a semipermeable membrane downregulated the release of IL-8 with or without cytomix stimulation. Stimulation with cytomix decreased nitrite production. Both neutrophil adherence and L-NAME pretreatment significantly inhibited the production of nitrite. The inhibition of neutrophil adherence to epithelial cells with ICAM-1 monoclonal antibody or a semipermeable membrane upregulated nitrite production. Pretreatment with L-NAME failed to modify the spontaneous release of IL-8, but significantly enhanced the response to adherence and cytomix. In conclusion, endogenous nitric oxide may play a role in preventing neutrophil adherence to lung epithelial cells, thus modulating concomitant IL-8 release.

Upregulation of inducible nitric oxide synthase and cytokine secretion in peripheral blood monocytes from pulmonary tuberculosis patients

SETTING

Peripheral blood monocytes (PBM) are the main source of alveolar macrophages, which have an upregulation of inducible nitric oxide synthase (iNOS) in pulmonary tuberculosis (TB). TNF-alpha and IL-1 beta are thought to be involved in the immune response to mycobacterial infection.

OBJECTIVE

To identify whether iNOS expression and cytokine release of PBM are upregulated and have a connection in TB infection.

DESIGN

The expression of iNOS immunoreactivity on PBM from TB patients and normal subjects was measured by loading with anti-macrophage iNOS polyclonal primary antibody analyzed by flow cytometry. Expression of iNOS mRNA in PBM was detected by RT-PCR. The spontaneous generation of nitrite and cytokines (IL-1 beta and TNF-alpha) by cultured monocytes was also determined.

RESULTS

Compared to normal subjects, iNOS immuno-reactivity, the capacity for spontaneous nitrite generation and the level of TNF-alpha or IL-1 beta secretion of PBM were significantly higher in TB patients. The amount of nitrite, TNF-alpha and IL-1 beta released from PBM of TB patients was inhibited by NG-monomethyl-L-arginine (L-NMMA), a competitive inhibitor of NOS. The level of iNOS immunoreactivity on PBM was highly correlated with nitrite generation both in all the subjects studied and in TB patients alone. Spontaneous TNF-alpha production showed a stronger correlation with nitrite production than with IL-1 beta.

CONCLUSION

The NO and cytokine synthase activities of monocytes appear to be concomitantly upregulated in response to mycobacterial infection. The enhanced NO generation by monocytes in TB patients may play an autoregulatory role in amplifying the synthesis of pro-inflammatory cytokines.

Multiple signals required for cyclic AMP-responsive element binding protein (CREB) binding protein interaction induced by CD3/CD28 costimulation

The optimal activation of cAMP-responsive element binding protein (CREB), similar to the full activation of T lymphocytes, requires the stimulation of both CD3 and CD28. Using a reporter system to detect interaction of CREB and CREB-binding protein (CBP), in this study we found that CREB binds to CBP only by engagement of both CD3 and CD28. CD3/CD28-promoted CREB-CBP interaction was dependent on p38 mitogen-activated protein kinase (MAPK) and calcium/calmodulin-dependent protein kinase (CaMK) IV in addition to the previously identified extracellular signal-regulated kinase pathway. Extracellular signal-regulated kinase, CaMKIV, and p38 MAPK were also the kinases involved in CREB Ser(133) phosphorylation induced by CD3/CD28. A reconstitution experiment illustrated that optimum CREB-CBP interaction and CREB trans-activation were attained when these three kinase pathways were simultaneously activated in T cells. Our results demonstrate that coordinated activation of different kinases leads to full activation of CREB. Notably, CD28 ligation activated p38 MAPK and CaMKIV, the kinases stimulated by CD3 engagement, suggesting that CD28 acts by increasing the activation extent of p38 MAPK and CaMKIV. These results support the model of a minimum activation threshold for CREB-CBP interaction that can be reached only when both CD3 and CD28 are stimulated.

[Effect of solution pH value on the chelation structure of zinc acexamate by electrospray ionization mass spectrometry]

AIM

To study the effect of solution pH value on the chelation structure of zinc acexamate.

METHODS

A series of samples at different solution pH values were prepared by 10% HCl or 1 mol.L-1 NH3.H2O. Then API/TOFMS with electrospray ion source was applied to assay the samples. The nitrogen curtain gas and nebulizer gas were adjusted to a constant flow rate of 0.6 microL.min-1 and 2 microL.min-1 respectively. Samples were infused into the electrospray interface using a 500 microL syringe pump at a flow rate of 5 microL.min-1. Mass spectra were acquired in positive ion modes by scanning over the range of m/z 100-1,000.

RESULTS

The chelation structure of zinc acexamate is stable at pH 2.54 and it can be easy to form the ion (M + ZnY)+ (Y = CH3CONH(CH2)5COO-) and (2M + Na)+ in this condition.

CONCLUSION

The drug is an effective antiulcer agent. It may decrease the acidity of stomach juice, and form a polymer to protect the ulcer.

Value of bronchoalveolar lavage combined with transbronchial lung biopsy in the diagnosis of peripheral lung cancer

BACKGROUND

Bronchoalveolar lavage (BAL) is a safe and established procedure to evaluate interstitial lung diseases and pulmonary tuberculosis. The diagnostic rate of peripheral lung cancer invisible through bronchoscopy applied by transbronchial lung biopsy (TBLB) is still low. The study was designed to evaluate whether BAL combined with TBLB might improve the positive value in the diagnosis of peripheral lung cancer.

METHODS

Thirty-seven of 72 patients who presented with peripheral lung lesions in chest radiography were proven to have a malignancy according to the final reports of cytology, histology, and clinical evidence. Each patient received BAL with or without TBLB. The patterns of chest radiography of the malignancies included 33 of infiltrative type and 4 of massive or nodular type.

RESULTS

BAL alone revealed positive malignant cells in 18 of 37 cases (sensitivity 48.6%), and the diagnostic value significantly increased to 73.0% (p < 0.05) with BAL + TBLB. In the infiltrative type of lung cancer, the diagnostic rate of BAL + TBLB (78.8%) was significantly improved compared to that of BAL alone (51.5%, p < 0.05). There was no difference of diagnostic value in those with nodular type. BAL + TBLB can achieve a very high diagnostic rate (100%) in cases of metastatic malignancy (n = 4). Only 2 patients developed bleeding post BAL + TBLB, and it was easily controlled by epinephrine spraying. One patient developed self-limited hemoptysis.

CONCLUSION

BAL + TBLB is a safe and valuable procedure to achieve a high sensitivity rate in the diagnosis of peripheral lung cancer, especially of the infiltrative type.

The value of transbronchial lung biopsy in the diagnosis of peripheral lung tumors according to cell type

BACKGROUND

Transbronchial lung biopsy (TBLB) is a useful diagnostic tool for peripheral lung tumors. However, the success rate is variable. Our study was designed to investigate the value of TBLB without fluoroscopic guidance in the diagnosis of variable cell types of peripheral lung cancers.

METHODS

A retrospective study was conducted to investigate a total of 597 patients who had undergone fiberoptic bronchoscopy for lung mass on chest X-ray in Chang Gung Memorial Hospital from January 1996 to December 1998. The lung masses were proven to be malignant by cytology and histology.

RESULTS

Of 358 patients (60.0%) proven with malignancy, 107 patients presented with peripheral lung cancer (17.9%), including 59 with adenocarcinoma, 26 with squamous cell carcinoma, 11 with poorly differentiated carcinoma, 3 with small cell carcinoma, and 8 with metastatic cancers. The diagnostic rate of peripheral lung cancer by TBLB reached 54.2%. The sensitivity rates of detection of non-small cell type by TBLB were adenocarcinoma, 50.9%; squamous cell carcinoma, 61.5%; and poorly differentiated carcinoma, 72.7%, while that of small cell carcinoma was 100%. In contrast, the sensitivity rate of TBLB for metastatic cancers was lower (12.5%) than for primary lung cancers. Repeated TBLB of peripheral lung cancers increased the diagnostic rate from 49.5% to 54.2%.

CONCLUSION

TBLB is an effective bronchoscopic sampling technique in the diagnosis of peripheral lung tumors without additional risk. The use of TBLB in the clinical routine should be encouraged.

Repair of cardiac defects through a shorter right lateral thoracotomy in children

BACKGROUND

Median sternotomy is a conventional approach for correction of cardiac defects for many years; however, the cosmetic result is poor. Therefore, right lateral thoracotomy was tested as an alternative procedure with a better cosmetic outcome.

METHODS

Between October 1994 and February 1999, 683 patients underwent correction of congenital cardiac malformations during a cardiopulmonary bypass through right lateral thoracotomy involving a shorter incision through the third or the fourth intercostal space. All of the patients were children. The average age was 3.26+/-1.67 years (range, 4 months to 7 years). The average weight was 13.59+/-4.37 kg (5 to 40). The patients had various cardiac defects and associated anomalies.

RESULTS

Only 2 patients died after operation, 1 from low cardiac output and the other from severe pulmonary infection. The hospital morbidity was lower. The mean cardiopulmonary bypass time was 58.67+/-35.11 minutes (range, 16 to 430 minutes), the mean aortic cross-clamping time was 35.03+/-24.84 minutes (range, 3 to 205 minutes). The postoperative average mechanical ventilation time was 19.23+/-39.11 hours (range, 2 to 391 hours), and the mean postoperative stay was 8.55+/-12.54 days (range, 5 to 293 days).

CONCLUSIONS

The right lateral thoracotomy incision is a safe and effective alternative to a median sternotomy for correction of cardiac defects. Advantages of this approach compared with median sternotomy are less injury, maintenance of the continuity and the integrity of the bony thorax, and prevention of the development of "pigeon-chesting." The scar is less visible, hence, the cosmetic result can meet patient expectations. This procedure is consistent with the idea of minimal invasive surgery.

Erythromycin inhibits beta2-integrins (CD11b/CD18) expression, interleukin-8 release and intracellular oxidative metabolism in neutrophils

Macrolides have therapeutic benefits on chronic inflammatory airway diseases. Thus, macrolides are supposed to have variable biological effects apart from antimicrobial activity. Neutrophil adherence and influx with oxidants and cytokines production implicates involvement in airway inflammation. To investigate whether erythromycin (EM) affects neutrophil activity in vitro, lipopolysaccharide (LPS)-treated neutrophils were continuously incubated for 4 h in the absence or presence of increasing doses of EM from 1 microg ml(-1) to 100 microg ml(-1) in the last 2 h. Leukocyte adhesion molecules Mac-1 and intracellular H2O2(DCFH) were determined by flowcytometric assay. IL-8 and TNFalpha in supernatant was measured by ELISA method. The expression of Mac-1 and mean intracellular DCF fluorescence intensity (DCFH) of neutrophils significantly increased after stimulation with LPS. Pretreatment with EM significantly decreased LPS induced Mac-1 expression on neutrophils compared with LPS stimulation only. EM alone (100 microg ml(-1)) also decreased Mac-1 expression on neutrophils. EM significantly reduced the LPS-increased DCFH. EM alone (100 microg ml(-1)) also caused a decrease in DCFH. Increasing doses of EM also significantly decreased the IL-8 released by LPS-stimulated neutrophils. In conclusion, EM exerts a direct effect on the neutrophils by downregulating the expression of beta2-integrin on neutrophils, thus leading to a decrease in the intracellular H2O2, as well as the production of IL-8. Our conclusion provides an explanation for the clinical efficacy of erythromycin in neutrophil-mediated airway inflammation.

Hypodense alveolar macrophages in patients with diabetes mellitus and active pulmonary tuberculosis

SETTING

Alveolar macrophages (AM), a heterogeneous cell population, play a critical role in eliminating mycobacterial infections in collaboration with lymphocytes. Patients with diabetes mellitus (DM) show increased susceptibility to pulmonary tuberculosis (TB) infection. It is still uncertain whether there is a defect in T cell or AM activation in patients with DM against TB infection.

OBJECTIVE

To study the difference in activation status of AM and T cells between patients with TB + DM and TB alone.

METHOD

The heterogeneity of AM from 14 patients with TB + DM, 9 with TB alone, 10 normal subjects and 8 DM alone patients, was studied using Percoll density fractionation. The intracellular H2O2 production of AM before and after stimulation with phorbol myristate acetate (PMA) or F-Met-Leu-Phen (FMLP) was assayed by loading cells with 2',7'-dichlorofluorescin (DCFH) and analyzed by flow cytometry. Lymphocytes subsets (CD3, CD4, CD8) and their activation status (CD25) in bronchoalveolar lavage were also measured.

RESULTS

The proportion of the least dense AM (< 1,030 g/ml) and the magnitude of DCFH oxidation of AM was higher in TB patients than in normal subjects, regardless of DM. Patients with TB + DM had a significantly lower proportion of the least density AM fraction than TB alone patients, regardless of disease extent. Among TB patients, the proportion of the least dense AM was inversely correlated with the bacterial load on sputum and the disease extent on chest radiograph. Stimulation of AM with PMA or FMLP induced an increase in the hypodense AM subpopulations and enhanced intracellular H2O2 generation in patients with TB + DM and to a similar extent in normal subjects, but not in patients with TB alone. There was no significant difference in CD3 numbers, CD4/CD8 ratio, and CD25+ cells between patients with TB alone and TB + DM. The activation status of AM or T lymphocytes from DM alone patients was not significantly different from those from normal subjects.

CONCLUSION

Hypodense subpopulations of AM increase in active TB patients and are related to the disease severity as well as activation status of AM. AM in TB patients complicated with DM was less activated, and may be contributory to the susceptibility to mycobacterial infection.

Nitric oxide modulates interleukin-1beta and tumor necrosis factor-alpha synthesis by alveolar macrophages in pulmonary tuberculosis

Interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha released from alveolar macrophages (AM) in pulmonary tuberculosis (TB) are important in host defense against mycobacterial infection. Nitric oxide (NO) production is enhanced in AM of TB patients. We examined whether NO was implicated in (IL)-1beta and TNF-alpha synthesis by AM of TB patients. Purified AM were retrieved by bronchoalveolar lavage from 11 TB patients and 10 normal subjects, and were cultured with or without the NO inhibitor N(G)-monomethyl-L-arginine (L-NMMA). The release of IL-1beta and TNF-alpha, and expression of their messenger RNAs (mRNAs), were determined by enzyme-linked immunosorbent assay and Northern blot analysis. The release of IL-1beta and TNF-alpha was greater from AM of TB patients than from AM of normal subjects. L-NMMA inhibited nitrite, IL-1beta, and TNF-alpha production in TB patients. The mRNA expression for IL-1beta and TNF-alpha was upregulated in TB patients and was depressed by L-NMMA. Immunocytochemistry done with a monoclonal antibody against the p65 subunit of nuclear factor (NF)-kappaB showed that NF-kappaB was highly expressed and translocated to the nuclei of AM from TB patients, and was inhibited by L-NMMA. Inhibition of NF-kappaB by pyrrolidine dithiocarbamate attenuated IL-1beta and TNF-alpha synthesis. In conclusion, enhanced NO generation by AM of TB patients plays an autoregulatory role in amplifying the synthesis of proinflammatory cytokines, probably through NF-kappaB activation.

Endotoxemia augments neurogenic plasma exudation in guinea pig lungs

BACKGROUND

Lipopolysaccharide (LPS) is closely associated with the development of infection-induced deleterious pulmonary reactions. In this study, we investigated the enhancement effects of LPS on tachykinin-mediated plasma exudation in the lungs of guinea pigs. The role of oxidants was also explored.

METHODS

Intravenous LPS (100 mu kg-1) or its vehicle was administered 0 to 3 hours prior to bilateral electrical or sham stimulation of the cervical vagus nerves in animals anesthetized with urethane and artificially ventilated. Plasma exudation into the lungs was assessed by measurement of extravasated 125I-albumin which had been intravenously administered before stimulation.

RESULTS

The plasma exudation in the lungs increased after bilateral cervical vagal stimulation. LPS alone did not induce significant plasma exudation. The vagally-mediated plasma exudation was enhanced by LPS with the peak effect 1 hour after LPS administration. LPS also enhanced exogenous substance P (10(-8) mol kg-1, i.v.)-induced plasma exudation. The vagally-induced plasma exudation was abolished by a specific neurokinin-1 (NK-1) receptor antagonist, L-732,138. The LPS-induced enhancement response was also attenuated by L-732,138. The vagally-induced plasma exudation was not affected by superoxide dismutase (SOD, 5000 U kg-1, i.p.) pretreatment. However, SOD significantly inhibited the LPS-enhanced neurogenic plasma leakage. The LPS-induced enhancement was not completely abolished by either L-732,138 or SOD pretreatment alone, but by a combination of both.

CONCLUSION

LPS augments neurogenic plasma exudation partly through NK-1 receptors to increase vascular permeability and partly via the generation of oxidative metabolites. Tachykinins released from nerve endings may contribute to endotoxin-related pulmonary inflammatory responses.

Increased level of exhaled nitric oxide and up-regulation of inducible nitric oxide synthase in patients with primary lung cancer

Monocyte-macrophage series have an important role in host surveillance against cancer. The cytotoxic/cytostatic activity of macrophages is, to a great extent, attributed to the up-regulation of inducible nitric oxide synthase (iNOS) and production of nitric oxide (NO). Here, in 28 patients with primary lung cancer and 20 control subjects, we measured the concentration of exhaled NO and nitrite in epithelial lining fluid (ELF) using a chemiluminescence NO analyser, and studied NOS expression in alveolar macrophages (AM) and lung tissues by flow cytometry; immunohistochemical analysis was also undertaken. The mean fluorescence intensity (FI) of iNOS expression in AM was significantly increased in patients with lung cancer (tumour side 263.5 +/- 15.2 FI, normal side 232.4 +/- 18.6 FI; n = 28) compared with that in control subjects (27.3 +/- 3.2 FI; n = 20, P< 0.001). The level of exhaled NO from cancer patients (16.9 +/- 0.9 p.p.b.; n = 28) was significantly higher than that in the control group (6.0 +/- 0.5 p.p.b.; n = 20, P < 0.001). The level of nitrite was also significantly higher in ELF from cancer patients (tumour side 271.1 +/- 28.9 nM and normal side 257.4 +/- 19.6 nM vs control subjects 32.9 +/- 4.1 nM; P< 0.001). The intensity of iNOS expression in AM was correlated with the level of exhaled NO (rs = 0.73, n = 76, P< 0.001) and the nitrite released in ELF (rs = 0.56, n = 76, P< 0.001). The nitrite generation of cultured AM from patients with lung cancer was significantly enhanced compared with that of control subjects after culture for 24 h (tumour side 5.75 +/- 0.69 and normal side 5.68 +/- 0.58 microM per 106 cells vs control group 38.3 +/- 3.6 nM per 106 cells; P< 0.001). The distribution of iNOS was identified in AM, tumour-associated macrophages, endothelium, chondrocytes, airway epithelium of both lungs and malignant cells (adenocarcinoma and alveolar cell carcinoma) of cancer patients. cNOS was labelled in alveolar macrophages, endothelial cells and nerve elements from lung tissue. Our results indicate that, in patients with primary lung cancer, the production of NO from alveolar macrophages was increased as a result of the up-regulation of iNOS activity. The increased NO production was not specific to the tumour side and might be attributed to the tumour-associated non-specific immunological and inflammatory processes of the host.

Increased exhaled nitric oxide in active pulmonary tuberculosis due to inducible NO synthase upregulation in alveolar macrophages

Nitric oxide (NO) plays an important role in resistance to Mycobacterium tuberculosis infection. Our aim was to determine whether inducible NO synthase (iNOS) expression and generation of reactive nitrogen intermediates (RNI) by alveolar macrophages (AM) are increased in patients infected with M. tuberculosis. NO levels in the exhaled air of 19 active pulmonary tuberculosis (TB) and 14 control subjects were measured using a chemiluminescence NO analyser. The expression of iNOS on AM was studied by labelling AM with anti-mac iNOS polyclonal antibody analysed with a flow cytometer. The spontaneous generation of RNI by cultured AM was also measured. Data are presented as mean+/-SEM. The level of NO in exhaled air was higher in patients with active TB (16.2+/-1.2 parts per billion (ppb)) compared to control subjects (6.5+/-0.9 ppb), p<0.0001. Exhaled NO decreased with anti-TB treatment. Compared to control subjects (29.0+/-4.5 fluorescence intensity (FI)), iNOS expression on AM was upregulated in TB patients (86.3+/-12.5 FI) p<0.001 and the capacity for spontaneous generation of nitrite was enhanced. Nitrite production was inhibited by N(G)-monomethyl-L-arginine (L-NMMA), a competitive inhibitor of iNOS. The expression of iNOS on AM was related to the concentration of exhaled NO (r=0.66, p<0.001) and the nitrite generation capacity of AM (r(s)=0.77, p<0.001). We conclude that the increase in exhaled nitric oxide observed in patients with active pulmonary tuberculosis is due to an upregulation of inhaled NO synthase expression in alveolar macrophages which have an enhanced capacity for nitric oxide production.

Inhaled gentamicin reduces airway neutrophil activity and mucus secretion in bronchiectasis

To investigate whether aerosolized gentamicin (GM) prevents myeloperoxidase (MPO)-mediated airway injury and mucus hypersecretion, a short course of aerosol therapy (3 d) with GM 40 mg or 0.45% saline (saline) twice per day was conducted. Twenty-eight patients with bronchiectasis and mucus hypersecretion after adequate chest care and hydration were enrolled in a randomized, double-blind fashion. MPO levels in sputum collected on arising were determined by fluorometric assay at 655 nm before and after treatment. The sputum MPO level significantly decreased in patients receiving aerosolized GM, from 0.22 +/- 0.04 to 0.14 +/- 0.04 U/g (n = 15), but not in patients with saline inhalation (0.23 +/- 0.03 to 0.17 +/- 0.02 U/g; n = 11). The daily sputum amount significantly decreased from 94.6 +/- 21.6 to 58.1 +/- 17.8 ml (n = 13, p < 0.01) in the GM group, whereas it increased from 78.6 +/- 25.4 ml to 120.5 +/- 33.9 ml (n = 11, p < 0.05) in the saline group. The change in the amount of daily sputum was related to that in the sputum MPO level in the GM group (r = 0.61; p < 0.01). Inhalation of GM, but not saline, significantly (p < 0.05) increased the value of peak expiratory flow (PEF) from 186.4 +/- 25.1 to 216.4 +/- 26.4 L/min and decreased the variability of PEF from 24.6 +/- 5.1 to 6.1 +/- 2.3 %. The nocturnal desaturation and the 6-min walking distances were also significantly improved in the GM group (11.2 +/- 3.8 to 0.6 +/- 0.5 min/h; 324.9 +/- 43.1 to 408.1 +/- 25.9 m; p < 0.05; respectively), but not in the saline group. Subjective improvements in the Borg scale and self-sputum assessment were found in the GM group only. In conclusion, aerosolized GM is effective in improving airway hypersecretion and inflammation in patients with bronchiectasis.

Cloning, sequencing, and expression of the rpoD gene encoding the primary sigma factor of Xanthomonas campestris

A DNA fragment encoding the primary sigma factor from Xanthomonas campestris pv. campestris was cloned and sequenced. The gene (rpoD) encodes a polypeptide of 622 amino acids with a calculated MW of 70,700. The deduced amino acid sequence exhibits extensive sequence homology to the conserved regions of the primary sigma factors from bacteria. The gene product expressed in Escherichia coli, detected by Western blot analysis, had a MW similar to that estimated for the purified protein in SDS-PAGE. The NH2-terminal amino acid sequence determined chemically matched with that deduced from the nucleotide sequence of the rpoD gene. The calculated pI value (9.31) for the X. campestris primary sigma factor is much higher than the values observed for the analogous proteins from other bacteria.

Increased production of hydrogen peroxide and expression of CD11b/CD18 on alveolar macrophages in patients with active pulmonary tuberculosis

SETTING

Alveolar macrophages (AM) are important in host defense against Mycobacterium tuberculosis (TB). beta 2-integrins, especially CD11a/CD18 and CD11b/CD18, are implicated in leukocyte migration, antigen presentation, phagocytosis, and production of reactive oxygen species.

OBJECTIVE

To explore the functional relevance of beta 2-integrin expression to intracellular H2O2 capacity of AM in TB patients.

DESIGN

In a prospective study, AM retrieved from 18 active pulmonary TB patients and 18 normal subjects were assessed for beta 2-integrin expression and intracellular H2O2 metabolism capacity by loading with anti-CD11a/CD18, anti-CD11b/CD18 monoclonal antibodies and 2',7' dichlorofluorescein diacetate (DCFH-DA) respectively, and analyzed by flow cytometry. AM from 8 normal subjects were stimulated with tumor necrosis factor-alpha (TNF-alpha, 10(5) units/ml) to examine the relationship between H2O2 production and CD11b/CD18 expression.

RESULTS

The magnitude of DCFH oxidation and CD11b/CD18 expression of AM was higher in TB patients than in normal subjects. The CD11b/CD18 expression was related to the magnitude of DCFH oxidation, but not to lymphocyte numbers or subpopulations (CD4, CD8, CD25). Stimulation of AM with TNF-alpha increased H2O2 production and CD11b/CD18 expression. Pretreatment with CD11b/CD18 monoclonal antibodies inhibited TNF-alpha-induced H2O2.

CONCLUSION

AM in TB patients possessed a higher capacity of oxidant metabolism. The increased CD11b/CD18 expression may be related to the increased respiratory burst response in AM against mycobacterial invasion.

Effect of nebulized fenoterol on spirometry, dyspnea sensation changes during exercise in patients with chronic obstructive pulmonary disease

Airflow limitation impairs exercise capacity in patients with chronic obstructive pulmonary disease (COPD). Bronchodilators have been shown to increase exercise tolerance in patients with COPD by mechanisms yet unclarified. We studied the effect of nebulized fenoterol (0.5 mg/ml) on the 6-minute walking test (WT) 60 mins after a control WT using a nebulized saline control in 16 patients with moderate to severe COPD. Before and immediately after each WT, the FEV1, FVC, O2, Saturation and dyspnea score (Borg breathlessness score,[BS]) were measured. Fenoterol had no significant effect on pre-exercise spirometry in our patients but maintained a significantly higher level of FEV1 (0.9 +/- 0.1L, p < 0.0001) and FVC (2.0 +/- 0.2L, p < 0.01) immediately after exercise than that after saline control nebulization (0.7 +/- 0.1L, 1.8 +/- 0.2L, respectively). Fenoterol significantly (p < 0.01) increased walking distance (WD) from 201.3 +/- 22.2m to 238.9 +/- 22.2m, but no difference was found in BS and oxygen saturation. The decline in FEV1 following the WT was shown to have an inverse relationship (r = - 0.74, p < 0.002) with the WD improvement (delta WD). Those who walked farther after fenoterol inhalation felt less dyspnea after exercise, also with an inverse correlation (r = -0.61, p < 0.02). These results suggest that fenoterol may improve exercise capacity by preventing airflow deterioration during exercise in patients with COPD. We also recommend the 6-minute walking test in the routine clinical assessment of COPD patients to evaluate the symptomatic benefit offered by betamimetic bronchodilators.