[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.

[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.

[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(QR)) 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.

[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.

[Study on periodic changes in onset of aortic dissection].

Objective: To investigate theperiodic changes in onset of aortic dissection. Methods: The clinical data of 1 121 patients with acute aortic dissection from Hebei province, treated at Fuwai hospital from January 1, 2010 to December 31, 2016, were collected and analyzed retrospectively. The regularity for the onset of aortic dissection was analyzed according to daytime (1:00 to 6:00, 7:00 to 12:00, 13:00 to 18:00, and 19:00 to 24:00), weekday, month, and quarter. Meanwhile,the differences in various type of aortic dissection patient were also compared. Results: The patients were (51.4±12.0) years old,77.88% (873 cases)were male and 69.05% (774 cases) were type A aortic dissection.The peak period for the onset of the disease in a day was from 13:00 to 18:00 (401 cases. 35.77%),and disease onset was less frequent from 1:00 to 6:00 (196 cases, 17.48%).The peak weekday of disease onset was Monday (173 cases, 15.43%) , and disease onset was less frequent on Friday (153 cases, 13.65%) . The peak month of disease onset was January (135 cases, 12.04%), and disease onset was less frequent in July(54 cases, 4.82%). The peak season of disease onset was winter (349 cases, 31.13%), and disease onset was less frequent in summer (184 cases, 16.41%). Number of disease onset was similar between ≥65 years old and<65 years old groups, with or without hypertension groups, with or without Marfan syndrome groups at different periods of a day, each weekday, and seasons(all P>0.05). Conclusion: There are periodic changes in the onset of acute aortic dissection,which is higher in winter than in summer, higher in the afternoon than in the morning.

Cinnamaldehyde induces cell apoptosis mediated by a novel circular RNA hsa_circ_0043256 in non-small cell lung cancer.

Cinnamaldehyde (CA), the primary chemical component of the Chinese traditional herb Cinnamomum cassia, is an effective cytotoxic agent against various human cancers. Our previous study indicated that CA could trigger apoptosis in three kinds of non-small cell lung cancer (NSCLC) cells. However, CA mechanism of action in NSCLC has not been unveiled completely. Herein, we showed that a novel circular RNA hsa_circ_0043256 was upregulated in NSCLC cells in response to CA treatment, as detected by microarray and real-time PCR. Hsa_circ_0043256 could inhibit cell proliferation and induce apoptosis, while hsa_circ_0043256 knock-down could promote cell proliferation and restrain apoptosis induced by CA. Bioinformatics analysis predicted that hsa_circ_0043256 could work as a miR-1252 sponge, which could in turn directly target a vital negative regulator of Canonical Wnt signaling, Itchy E3 ubiquitin protein ligase (ITCH), as validated by dual-luciferase assay. Western blot results further confirmed that hsa_circ_0043256 could upregulate ITCH expression, whereas miR-1252 could partially abolish this effect. Interestingly, hsa_circ_0043256 knock-down could weaken Wnt/ß-catenin pathway inhibition induced by CA. Finally, we discovered that CA induced apoptosis and meanwhile upregulated hsa_circ_0043256 expression in vivo. Immunohistochemical analysis revealed that ITCH expression was positively association with hsa_circ_0043256 levels. Above all, we characterized a new mechanism mediated by hsa_circ_0043256/miR-1252/ITCH axis in CA function against NSCLC, providing a novel insight into lung cancer therapy.

Early influence of valve-related anticoagulation on false lumen thrombosis in aortic dissection patients after stented elephant trunk surgery.

BACKGROUND: Aim of the study was to assess the influence of anticoagulation on the false lumen after a stented elephant trunk procedure with mechanical valve replacement for aortic dissection patients. METHODS: Between 2003 and 2008, 181 out of 232 aortic dissection patients undergoing stented elephant trunk procedure concomitant with arch and/or proximal surgery were enrolled in this study. Fifty-five patients received an aortic valve replacement (AVR) with mechanical prosthesis. Patients were divided into two groups: with and without AVR. The aorta was evaluated by CT, and the diameter ratios between the true lumen and the aorta were calculated and the extent of thrombosis of the false lumen was quantified. RESULTS: Follow-up CT study at one year showed a significant difference between groups, mainly in the diameter ratios of the stent and aorta at the same level (P=0.003, at the stent end). Accordingly, CT data after hospital discharge differed significantly with regard to the extent of false lumen thrombosis at the carina level (P=0.020, at one year). Over one year after surgery, the residual false lumen around the stent-graft achieved complete thrombosis obliteration in 87.3% of patients with AVR and in 98.4% without AVR (P=0.005). CONCLUSIONS: Valve-related anticoagulation is associated with delay in false lumen thrombosis around the stent-graft.

Factors leading to obstructive granulation tissue formation after ultraflex stenting in benign tracheal narrowing.

BACKGROUND: This retrospective study aimed to determine the factors leading to obstructive granulation tissue formation after the placement of a self-expandable metallic stent (SEMS) in patients with benign tracheal disease. METHODS: From 2001 to 2007, a total of 67 patients (age: 62.1 +/- 15.4 years; range: 23-87 years) with benign tracheal disease received 75 ultraflex SEMS in our institution. RESULTS: There were 35 SEMSs complicated by obstructive granulation tissue formation out of the 75 stents placed in patients with tracheal disease, giving an incidence of 47.8 % (32/67 patients). The median time until developing granulation tissue was 106 days (IQR, 46-396). Structural airway obstruction prior to SEMS implantation independently predicted obstructive granulation tissue formation after SEMS implantation (odds ratio: 3.84; 95 % CI: 1.01-8.7; P = 0.04). Time to granulation tissue detection was shorter in patients with structural airway obstruction before SEMS implantation (structural airway obstruction vs. dynamic collapse airway: median [IQR] 95 [38-224, n = 26] vs. 396 days [73-994, n = 9]; P = 0.02). CONCLUSIONS: Obstructive granulation tissue formation is not uncommon after SEMS implantation and structural airway obstruction prior to SEMS implantation is an independent predictor. Although SEMS implantation should be restricted to a select population, it may be placed in patients not suitable for surgical intervention or rigid bronchoscopy with anesthesia because of poor pulmonary function.

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.

Metallic stent and flexible bronchoscopy without fluoroscopy for acute respiratory failure.

Stent implantation has been reported to facilitate liberation from mechanical ventilation in patients with respiratory failure due to central airway disease. The present retrospective cohort study sought to evaluate the risk and benefit of stent implantation via bronchoscopy without fluoroscopic guidance in mechanically ventilated patients. From July 2001 to September 2006, 26 patients with acute respiratory failure were recruited. A bronchoscope was inserted through a mouth guard into the space between the tracheal wall and the endotracheal tube. A guide wire was inserted via the flexible bronchoscope to the lesion site. The bronchoscope was reintroduced through the endotracheal tube. Under bronchoscopic visualisation, the delivery catheter was advanced over the guide wire to deploy the stent. These procedures were successfully performed in 26 patients, with 22 stents placed in the trachea and seven in the main bronchus. Of the 26 patients, 14 (53.8%) became ventilator independent during their stay in the intensive care unit. Severe pneumonia was the most common cause, in seven (58.3%) out of 12 patients, for continued ventilator dependence after stenting. Granulation tissue formation was found in seven patients during the follow-up period. It is concluded that metallic stents can be safely implanted without fluoroscopic guidance in patients with respiratory failure, to facilitate ventilator independence.

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.

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 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.

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.

White as a reporter gene to detect transcriptional silencers specifying position-specific gene expression during Drosophila melanogaster eye development.

The white+ gene was used as a reporter to detect transcriptional silencer activity in the Drosophila genome. Changes in the spatial expression pattern of white were scored in the adult eye as nonuniform patterns of pigmentation. Thirty-six independent P[lacW] transposant lines were collected. These represent 12 distinct pigmentation patterns and probably 21 loci. The spatial pigmentation pattern is due to cis-acting suppression of white+ expression, and the suppression probably depends on cell position rather than cell type. The mechanism of suppression differs from inactivation by heterochromatin. In addition, activation of lacZ in P[lacW] occurs also in specific patterns in imaginal discs and embryos in many of the lines. The expression patterns of white+ and lacZ may reflect the activity of regulatory elements belonging to an endogenous gene near each P[lacW] insertion site. We speculate that these putative POSE (position-specific expression) genes may have a role in pattern formation of the eye as well as other imaginal structures. Three of the loci identified are optomotor-blind, engrailed and invected. teashirt is also implicated as a candidate gene. We propose that this "silencer trap"' may be an efficient way of identifying genes involved in imaginal pattern formation.

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.