Cross-cultural invariance of the Academic Expectations Stress Inventory: Adolescent samples from Canada and Singapore

We provide further evidence for the two-factor structure of the 9-item Academic Expectations Stress Inventory (AESI) using confirmatory factor analysis on a sample of 289 Canadian adolescents and 310 Singaporean adolescents. Examination of measurement invariance tests the assumption that the model underlying a set of scores is directly comparable across groups. This study also examined the cross-cultural validity of the AESI using multigroup confirmatory factor analysis across both the Canadian and Singaporean adolescent samples. The results suggested cross-cultural invariance of form, factor loadings, and factor variances and covariances of the AESI across both samples. Evidence of AESI's convergent and discriminant validity was also reported. Findings from t-tests revealed that Singaporean adolescents reported a significantly higher level of academic stress arising from self expectations, other expectations, and overall academic stress, compared to Canadian adolescents. Also, a larger cross-cultural effect was associated with academic stress arising from other expectations compared with academic stress arising from self expectations.     

Comfort of fenestrated hydrogel lenses

A controlled, double-masked, randomized study was conducted on ten subjects to determine the effect of fenestration size on the initial comfort of hydrogel contact lenses. Four fenestrated lenses were tested, each lens containing four mid-peripheral fenestrations of the same size. The diameter of the fenestrations used in the four lenses ranged from 0.39 to 0.96 mm. An unfenestrated lens was also tested. All lenses were made of HEMA and were ordered with the following specifications: -3.00 D, 14.0 mm diameter, 8.4 mm back central optic radius and 0.06 mm centre thickness. There was a significant negative correlation between comfort and fenestration size, indicating that larger fenestrations are less comfortable. Even the lens with the smallest fenestrations (0.39 mm) was significantly less comfortable than the unfenestrated lens. The implication of this finding is that fenestrations may not be clinically efficacious in view of the poor comfort (and presumably increased mechanical effect of the fenestration edges on the tarsal conjunctiva) of fenestrated lenses.     

Effects of arginine vasopressin (AVP) infusions on circulating concentrations of platelet AVP, factor VIII: C and von Willebrand factor

To study the possible role of arginine vasopressin (AVP) in the control of haemostasis AVP infusions at 3 doses (0.1, 0.2 and 0.3 mU/kg/min) were performed in 6 male volunteers. Both plasma and platelet AVP concentrations rose in a dose-related manner. At doses of 0.2 and 0.3 mU/kg/min there was an increase in the plasma concentrations of both plasma Factor VIII and von Willebrand factor. The data support the hypothesis that AVP, by interacting with platelets and stimulating factor VIII and von Willebrand factor release, plays a role in the control of haemostasis.     

Angiopoietin1/Tie2 and VEGF/Flk1 induced by MSC treatment amplifies angiogenesis and vascular stabilization after stroke.

Bone marrow stromal cells (MSCs) increase vascular endothelial growth factor (VEGF) expression and promote angiogenesis after stroke. Angiopoietin-1 (Ang1) and its receptor Tie2 mediate vascular integrity and angiogenesis as does VEGF and its receptors. In this study, we tested whether MSC treatment of stroke increases Ang1/Tie2 expression, and whether Ang1/Tie2 with VEGF/ vascular endothelial growth factor receptor 2 (VEGFR2) (Flk1), in combination, induced by MSCs enhances angiogenesis and vascular integrity. Male Wistar rats were subjected to middle cerebral artery occlusion (MCAo) and treated with or without MSCs. Marrow stromal cell treatment significantly decreased blood-brain barrier (BBB) leakage and increased Ang1, Tie2, and occludin (a tight junction protein) expression in the ischemic border compared with MCAo control. To further test the mechanisms of MSC-induced angiogenesis and vascular stabilization, cocultures of MSCs with mouse brain endothelial cells (MBECs) or astrocytes were performed. Supernatant derived from MSCs cocultured with MBECs significantly increased MBEC expression of Ang1/Tie2 and Flk1 compared with MBEC alone. Marrow stromal cells cocultured with astrocytes also significantly increased astrocyte VEGF and Ang1/Tie2 expression compared with astrocyte culture alone. Conditioned media from MSCs alone, and media from cocultures of MSCs with astrocytes or MBECs, all significantly increased capillary tube-like formation of MBEC compared with control Dulbecco's modified Eagle's medium media. Inhibition of Flk1 and/or Ang1 significantly decreased MSC-induced MBEC tube formation. Knockdown of Tie2 expression in MBECs significantly inhibited MSC-induced tube formation. Our data indicate MSC treatment of stroke promotes angiogenesis and vascular stabilization, which is at least partially mediated by VEGF/Flk1 and Ang1/Tie2.     

SMI-32 immunoreactivity in human striate cortex during postnatal development.

SMI-32, an antibody which recognizes the non-phosphorylated epitopes on the neurofilament proteins was used to study the morphological changes in the human striate cortex during postnatal development. Striate cortices from 12 autopsied patients with ages ranging from 1 day to 70 years were obtained. Using the avidin-biotin-peroxidase method, the first SMI-32 immunoreactive neurons were identified at sublayers Vb/VIa on the first postnatal day. At 5 months, the next group of neurons to develop immunoreactivity were in IVb. By 15 months, SMI-32 immunoreactive neurons were observed at III, IVa, IVb, V and VI. The changes in SMI-32 immunoreactivity (ir) were stabilized from 3 years and after. The SMI-32 ir in the striate cortex could be a useful morphological correlate for studying developmental diseases affecting the neocortex.     

年龄小于45岁原发性慢性闭角型青光眼的显微手术治疗

目的探讨原发性慢性闭角型青光眼年轻患者临床治疗的经验和体会。方法对临床收治的41例52眼、年龄〈45岁、临床确诊为进展期或晚期原发性慢性闭角型青光眼的病例进行抗青光眼显微手术处理的病例进行回顾性分析。结果随访时间平均（32．50±5．08）个月；男16例，女25例；进展期28眼，晚期24眼；52眼均行抗青光眼手术-复合式小梁切除手术治疗；眼轴长平均（22．40±1．63）mm，其中〈21mm占17．31％，小眼球占13．46％；前房深度平均（1．90±0．39）mm，其中〈1．9mm占61．46％；超声生物显微镜检查高褶虹膜构型占59．62％，其中睫状突位置靠前者10眼；术前平均眼压（41．73±12．26）mmHg，末次术后平均眼压（12．03±4．57）mmHg，术前后眼压差异有统计学意义（t=3．520，P〈0．001）。术后并发症主要有浅前房，恶性青光眼。恶性青光眼手术处理方式包括玻璃体抽液、前段玻璃体切割以及超声乳化白内障吸除加人工晶状体植入术治疗。4眼因眼压控制不理想，行二次抗青光眼手术治疗。结论年轻原发性慢性闭角型青光眼患者，女性多见，多伴有眼轴短、前房浅等特点，抗青光眼复合式小梁手术治疗要注意防治术后浅前房、恶性青光眼的发生。术前详细检查、手术操作精细以及有效处理术后并发症将有助于提高手术成功率和减少并发症。     

The Stanford experience with combined procarbazine, Alkeran and vinblastine (PAVe) and radiotherapy for locally extensive and advanced stage Hodgkin's disease.

This report describes the efficacy and toxicity of PAVe (procarbazine, Alkeran, vinblastine) and irradiation (RT) in the management of 159 patients with locally extensive or advanced stage Hodgkin's disease (HD) at Stanford University. Patients received six courses of chemotherapy alternating with RT. The extent of RT and the schedule of treatment varied according to the stage of disease. About 2/3 of patients received PAVe/RT in the setting of prospective, randomized clinical trials. The rate of complete response was 93%. With a median follow-up of seven years (range 2-17), the 15 year actuarial freedom from progression (FFP) is 78% and overall survival is 75%. Ten-year FFP by stage is: 80% for locally extensive stage II, 90% for stage IIIA and 70% for stage IIIB. Excellent and equal results were attained with PAVe/RT vs. MOP(P) (mustard, Oncovin, procarbazine with or without prednisone)/RT in the randomized combined modality studies. Progression or recurrence was documented in 30 patients and was more common in irradiated sites. PAVe was well tolerated acutely. There were no treatment related fatalities. Twenty-three (14%) patients were admitted to the hospital for neutropenic fever. Five second malignancies have occurred after PAVe/RT only: one myelodysplastic syndrome, one acute myelogenous leukemia, one non-Hodgkin's lymphoma and two solid tumors including a case of non-small cell lung cancer and an in situ carcinoma of the cervix. Three patients died from myocardial infarction several years after the completion of treatment. These mature data show that PAVe/RT is effective and well-tolerated therapy for locally extensive stage II and IIIA/B HD.(ABSTRACT TRUNCATED AT 250 WORDS)     

Influence of finishing time on marginal sealing ability of new generation composite bonding systems

Although variation in finishing techniques has been shown to affect microleakage, little research has been published on the influence of finishing time on the marginal sealing ability of new generation composite bonding systems. The objective of the present study was to evaluate the influence of finishing time on the enamel and dentine marginal sealing ability of four new generation composite systems. Two class V preparations, which were solely in enamel or dentine, were made on the buccal surfaces of 96 freshly extracted molar teeth. The teeth were randomly divided into four groups of 24 and restored with composite resin (Silux Plus^®) utilizing the following bonding systems: Scotchbond Multi-purpose^®, Fuji Bond LC^®, Prime & Bond 2·0^® and Bisco One-step^®. Half of the restorations in each group were finished immediately after light polymerization and stored for 1 week. For the remaining restorations, finishing was delayed for 1 week. The storage medium was isotonic saline at 37°C throughout the experiment. All restorations were then thermocycled, subjected to dye penetration testing, sectioned and scored. The results suggest that the finishing of composite restorations, bonded with the bonding systems evaluated, should be carried out immediately after light polymerization. Delayed finishing does not improve but instead can be detrimental to the marginal seal of the restorations. The effects of delayed finishing are, however, both bonding system and tissue specific.