重组人血小板源性生长因子增加细胞外信号调节激酶磷酸化促进糖尿病大鼠全层皮肤缺损创面愈合

目的 在体观察重组人血小板源性生长因子（recombinant human platelet—derived growth factor，rhPDGF）促进糖尿病大鼠全层皮肤缺损创面修复可能涉及的细胞和分子机制，研究其可能涉及的信号通路。方法 26只糖尿病大鼠，每只动物背部制备4个全层皮肤缺损创面，选取其中52个创面，随机分成3组，即对照组，创面自然愈合；rhPDGF治疗组，创面rhPDGF用量为7．0μg／cm^2；赋形剂组，创面用等量赋形剂凝胶。观察治疗后3、7和14d创面肉芽形成、胶原沉积、再上皮化速率以及炎性细胞浸润情况，并采用免疫荧光和免疫组织化学技术观察创面周围和创面修复细胞内细胞外信号调节激酶1／2（extracellular signal—regulated kinase1／2，ERK1／2）磷酸化和增殖细胞核抗原（proliferative cell nuclear antigen，PCNA）的表达。结果 组织学观察，rhPDGF治疗组创面可见大量炎性细胞浸润，毛细血管胚芽及成纤维细胞明显多于另两组（P〈0．05）；胶原沉积明显，肉芽组织生长活跃，创面收缩显著，与对照组比较差异有统计学意义（P〈0．05）。免疫学研究显示，应用rhPDGF7～14d后，rhPDGF治疗组ERK1／2明显强于对照组和赋形剂组（P〈0．05）；且损伤后3～7d rhPDGF治疗组修复细胞PCNA的表达明显高于对照组和赋形剂组（P〈0．05）。结论 rhPDGF促糖尿病大鼠刨面愈合的作用部分是通过ERK1／2信号通路的磷酸化来完成的。     

Multivariate comparison of elemental concentrations in human teeth

R-mode factor analysis was applied to characterize the chemical composition of human teeth investigated by particle induced X-ray emission (PIXE), Rutherford backscattering spectrometry (RBS) and X-ray fluorescence (XRF) techniques. The approach developed in this study enabled the separation between essential mineral teeth components and the pollutants deposited in teeth tissues during the human life. The three independent sources of metals incorporated in human teeth were found. The first source, representing about 43% of the variance of the concentration data, was characterized by pollutant elements of power industry emissions. The second factor was loaded with toxic elements of general urban pollution. The third factor represented the tooth source as it contained mainly large fractions of the mineral components of the tooth tissue as Ca and K.     

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.     

Vascular endothelial growth factor in psoriasis: an indicator of disease severity and control

Background  Psoriasis is a chronic disease characterized by abnormal epidermal proliferation, inflammation and angiogenesis. It has been reported that vascular endothelial growth factor (VEGF) is overexpressed in lesional psoriatic skin and its serum levels are significantly elevated in patients with moderate to severe disease.
Objective  This study aims to evaluate the possible role of VEGF in the pathogenesis of psoriasis, and its significance as an indicator of disease severity and control.
Methods  Thirty patients with moderate to severe psoriasis and 10 healthy controls were subjected to baseline evaluation of VEGF. Patients were divided into three groups according to the received treatment: psoralen plus ultraviolet A (PUVA) thrice weekly (group 1), acitretin 50 mg daily (group 2), and combined PUVA twice weekly and acitretin 25 mg daily (group 3).Treatment continued for 16 weeks or up to clinical cure. Every patient was subjected to severity evaluation by Psoriasis Area and Severity Index (PASI) and measurement of serum VEGF before and after treatment.
Results  Mean serum levels of VEGF were significantly elevated in patients (327 ± 66.2 pg/mL) than control subjects (178 ± 83.4 pg/mL). A highly significant correlation was found between VEGF and PASI score, but not with other variables. The best clinical response, the least side-effects and the highest reduction of VEGF serum levels were achieved by the combined therapy.
Conclusion  The present study supported the proposed role of VEGF in the pathogenesis of psoriasis, and suggested that it could serve as a good indicator of disease severity and control.     

The high prognostic value of the histologic grade at the deep invasive front of tongue squamous cell carcinoma

BACKGROUND: Although many histopathologic factors in squamous cell carcinoma of the tongue predict the prognosis, the major predictive factors have not been identified clearly. This study analyzed the prognostic value of the histologic grade at the deep invasive front of tongue squamous cell carcinoma. METHODS: The clinicopathologic features of 124 consecutive patients seen between January 1985 and December 1999 with previously untreated squamous cell carcinoma of the tongue were reviewed. Their mean age was 58.5 years (range: 23-90) and the male-female ratio was 1.8: 1 (79 men and 45 women). There were 41, 40, 30, and 13 cases at stage I to stage IV, respectively. The clinicopathologic factors, especially the histologic grade at the deep invasive front (invasive front grade, IFG), were analyzed to determine factors predicting prognosis. RESULTS: The 5-year disease-free survival rate of the patients treated with curative aim only was 66.7%. Clinicopathologic factors significantly associated with the prognosis were T classification, tumor size, stage classification, tumor depth, macroscopic appearance, cervical lymph node metastasis (nodal metastasis), microvascular invasion, and IFG. In a multivariate analysis, patients with tumor depth >/=4 mm, IFG >/=8 points, and nodal metastasis had a reduced disease-free survival and IFG >/=11 points had a predictive value for nodal metastasis (odds ratio: 7.34; P = 0.0019). CONCLUSION: This study found that a high IFG malignancy score had a high prognostic value for squamous cell carcinoma of the tongue.     

脐血单核细胞对VD大鼠认知功能及脑组织BDNF的影响

目的观察颈内动脉输注脐血单核细胞(Human cord blood mononuclear cells,HCMNCs)对血管性痴呆(Vascular dementia,VD)大鼠认知功能及脑组织脑源性神经营养因子(Brain-derivedneurotrophicfactor,BDNF)含量的影响。方法改良Pulsinellis四血管阻断法建立VD大鼠模型;体外分离HCMNCs,术后24h颈内动脉输注数量为3×106/0.5ml的BrdU标记细胞;利用穿梭箱系统和ELISA法检测注射HCMNCs后2、4、8周VD大鼠学习记忆能力以及脑组织BDNF含量的变化。结果模型组大鼠主动回避反应比率明显低于对照组(P<0.01),治疗组较模型组显著提高(P<0.01)。术后2周模型组大鼠脑组织BDNF含量较对照组明显增高(P<0.01),4周时达到高峰(P<0.01),8周时则明显下降,与2周时相比有显著性差异(P<0.05);颈内动脉输注HCMNCs后治疗组大鼠脑组织BDNF含量较模型组显著升高(P<0.01),4周时最高(P<0.01),8周时略有下降,但仍维持在较高水平,与4周时相比无显著性差异(P>0.05)。结论颈内动脉输注HCMNCs可显著改善VD大鼠学习记忆能力,增加VD大鼠脑组织BDNF含量,具有脑保护作用。     

Angiolipoma of the buccal mucosa: a possible role of mast cell-derived VEGF in its enhanced vascularity

A case of angiolipoma occurring in the buccal mucosa of a 69-year-old male is described. The patient had noticed a painless mass in his buccal mucosa for 2 years. The surgically removed tumor, measuring 9 mm in diameter, was mainly located in the submucosal layer with focal expansion into the muscle layer. Histologically, the tumor was well-demarcated and composed of proliferations of mature fat cells and fibrous connective tissue containing many small blood vessels, which were evenly distributed. There was diffuse infiltration of a large number of mast cells, which were immunopositive for vascular endothelial growth factor (VEGF) especially around blood vessels, suggesting that VEGF produced by mast cells in angiolipomas plays an important role in the vascular proliferation in this particular tumor.     

粒细胞集落刺激因子治疗下肢缺血性疾病

目的探讨粒细胞集落刺激因子(rhG-CSF)对下肢缺血模型血管新生的影响。方法制作兔左下肢缺血模型,术后随机分为rhG-CSF治疗实验组(n=24)和对照组(n=24);应用流式细胞学技术、动脉造影、免疫组织化学染色检查,比较两组外周血CD34 细胞的含量、缺血下肢侧枝血管计数及肌肉毛细血管密度。结果治疗后3 d实验组CD34 含量(%)为(0.7150±0.0873)明显高于对照组(0.3983±0.0853),差异有统计学意义(P<0.01);实验组在第15、30天时侧枝血管计数(6.33±0.82、9.17±0.75)均高于对照组(3.33±0.52、4.17±0.75)(P<0.01);第40天实验组内收肌毛细血管密度平均为8.5/HP,明显高于对照组4.2/HP(P<0.01)。结论rhG-CSF可以增加兔缺血下肢的毛细血管数量,有促进血管新生的作用。     

Inhibition and reversal of platelet-rich arterial thrombus in vivo: direct vs. indirect factor Xa inhibition

BACKGROUND/OBJECTIVE: The efficacy of a direct factor (F)Xa inhibitor, ZK-807834, was compared with indirect inhibition by enoxaparin for inhibition and deaggregation of acute platelet-rich thrombi in a well-characterized porcine carotid injury model. METHODS: A crush injury was performed on a randomly chosen carotid artery and the thrombus allowed to propagate for 30 min. Pigs then received intravenous drug for 35 min: ZK-807834-Dose 1 (40 microg kg(-1) bolus + 1.5 microg kg(-1) min(-1) infusion, n=6); ZK-807834-Dose 2 (20 microg kg(-1) bolus + 0.75 microg kg(-1) min(-1) infusion; n=6); enoxaparin (1 mg kg(-1) bolus; n=6); or saline (n=6). Five minutes after drug initiation, the contralateral artery was injured. Thrombus size was monitored by scintillation detection of autologous 111In-platelets. RESULTS: The prothrombin time ratio was 2.2 +/- 0.1; 1.4 +/- 0.3; 1.2 +/- 0.9 and 1.1 +/- 0.2, respectively. ZK-807834-Dose 1 significantly inhibited carotid platelet deposition (525 +/- 226 x 10(6) cm(-2); P = 0.008), whereas ZK-807834-Dose 2 (2325 +/- 768) and enoxaparin (1236 +/- 383) were not different from saline (2776 +/- 642). Thrombus deaggregation was greatest for animals receiving ZK-807834-Dose 1 (473 +/- 185). Neither ZK-807834-Dose 2 (1588 +/- 480) nor enoxaparin (1618 +/- 686) was different from saline control (2222 +/- 598). CONCLUSIONS: Direct FXa inhibition with ZK-807834, at a prothrombin time ratio of 2.2, effectively inhibits thrombosis and promptly deaggregates thrombi induced by arterial injury. In contrast, indirect FXa inhibition with enoxaparin was ineffective.