Transient intrauterine hypotension: effect on newborn rat brain

Intrauterine perfusion failure can cause cerebral malformations. We investigated the effect of transient maternal hypotension on newborn rat brain by inducing hypovolemic hypotension for 2.5 h during early embryonic day 7 (E7) or late (E15) gestation in pregnant rats. We found an increase in the number of TUNEL-positive cells within the periventricular germinative matrix in pups subjected to early gestational hypotension and within the cerebral cortex in those subjected to late gestational hypotension in comparison to sham control animals. These results suggest that episodic maternal hypovolemic hypotension may affect the fetal brain, and apoptotic mechanisms may mediate this effect.     

An unusual presentation of spontaneous sub‐conjunctival haematoma in a patient receiving warfarin

A 65‐year‐old man on warfarin therapy with a sudden spontaneous onset of sub‐conjunctival haematoma associated with bloody tears was assessed in the clinic following a referral from an optometrist. Due to discomfort, diplopia and lagophthalmos, the haematoma necessitated suspension of warfarin therapy and a surgical evacuation. The sub‐conjunctival haematoma in a patient receiving warfarin can pose a significant management challenge.     

A case of leukoencephalopathy with vanishing white matter

A 6-year old Turkish boy with a recently defined entity: "leukoencephalopathy with vanishing white matter" is described. He was born to consanguinous parents. His psychomotor development was normal till he first presented with fever and generalized tonic-clonic seizures at the age of 2.5, followed by rapid motor and mental deterioration. Decerebrate posture and marked spasticity subsequently developed. The initial MRI examination showed diffuse involvement of white matter, including subcortical U-fibers, with signal intensity parallel to CSF on all sequences. The white matter appeared swollen. The ventricles were slightly enlarged and there was cavum septi pellucidi et vergae. The posterior crus of the internal capsule, external and extreme capsules were affected. Cerebellar hemispheres and vermis showed atrophy. The involvement pattern of brainstem was noteworthy in that pontine tegmentum and cruri cerebri were affected. Follow-up MRI obtained after three years did not show any interval change. Brain biopsy showed thinned cortex with relatively preserved cortical layering and neuronal structure. There was rarefaction of the white matter with cystic degeneration. Fibrillary gliosis and increased number of oligodendroglial cells were observed within the cerebral white matter.     

Community‐based diabetic retinopathy screening in Hong Kong: ocular findings

Background: Diabetic retinopathy is one of the most common causes of blindness. Timely retinal evaluation is known to prevent or minimise visual loss. This study compared the prevalence of ocular disorders in patients who have and have not undergone a retinal examination since diagnosis of their type 2 diabetes mellitus (T2DM). Such data might be useful for planning purposes by health care authorities and agencies in Hong Kong. Methods: Patients with T2DM aged 30 years or over presented for standardised interviews and screening for diabetic retinopathy. The presence of ocular disorders was recorded and the severity of the retinopathy, if any, was graded using the Early Treatment Diabetic Retinopathy Study (ETDRS) classification. Results: For the 1058 subjects who participated in this study, the mean age at examination was 61.8 ± 10.5 (SD) years (range, 31–93 years). For the 891 subjects with known diabetes for one year or longer, 62.7 per cent had never undergone an evaluation for diabetic retinopathy since diagnosis of their T2DM. Of the 891 subjects, gradable fundus photographs were available for 853 subjects and nearly 2.0 per cent of these had sight‐threatening retinopathy based on the ETDRS classification. Those who had not had an eye examination since diagnosis of their T2DM were more likely to have sight‐threatening retinopathy than those who had a retinal evaluation (2.6 versus 0.6 per cent; p = 0.04). Conclusion: In our sample, over 60 per cent of patients with T2DM for one year or longer had not had a retinal assessment since diagnosis. The risk of developing sight‐threatening diabetic retinopathy appears to be higher for those who have not had a retinal assessment.     

脂肪干细胞与骨髓间充质干细胞心肌样分化特性的比较

目的：骨髓间充质干细胞与脂肪干细胞均具有分化为心肌细胞的潜能。观察脂肪干细胞体外诱导分化为心肌细胞的特性及相关基因表达，比较骨髓间充质干细胞与脂肪干细胞心肌分化能力的差异。方法：实验于2006—08／2007—04在吉林省耳鼻咽喉研究所和教育部吉林大学人兽共患病重点实验室完成。①实验材料：脂肪组织标本来源于本院手术患者，所有患者知情同意，术中收集多余的皮下脂肪。（爹实验方法：分离培养人脂肪干细胞，用5-氮胞苷诱导传4～6代的脂肪干细胞分化，平行培养第5代骨髓间充质干细胞，诱导条件相同，对照组培养液不添加任何诱导因子。③实验评估：采用免疫荧光技术观察脂肪干细胞和骨髓间充质干细胞表达结蛋白Desmin和肌钙蛋白TroponinT的阳性细胞率。通过即时RT．PCR的方法检测诱导过程中细胞内GATA-4和NKX2．5的mRNA水平。结果：脂肪干细胞经5-氮胞苷诱导后3周，肌性基因标志结蛋白desmin和肌钙蛋白Troponin—T阳性细胞明显增加。与骨髓间充质干细胞组比较，脂肪干细胞表达心肌特异蛋白的阳性细胞率在诱导后第14天明显升高，而在第21天时，两组细胞的阳性表达率均达到60％左右，无明显的统计学差别，未加任何诱导条件的脂肪干细胞对照组培养14d时有2．5％和1．6％的细胞表达Desmin，Troponin．T，在骨髓问充质干细胞对照组未见心肌标记蛋白的阳性表达。即时PCR检测结果发现，诱导组与未经诱导组的脂肪干细胞均表达GATA-4和NKX2．5，骨髓间充质干细胞组在诱导后第7天出现GATA-4和NKX25的转录活性。结论：体外培养的脂肪干细胞能够被5-氮胞苷诱导分化为心肌样细胞，并且具有自发分化的能力，与骨髓间充质干细胞相比，脂肪干细胞的早期分化特性更有利于心肌干细胞移植治疗。     

达托霉素在中性粒细胞减少伴发热成人肿瘤患者中的药动学

达托霉素为第一个环脂肽类抗菌药,体外对万古霉素耐药肠球菌、甲氧西林耐药葡萄球菌及糖肽类耐药金葡菌等革兰阳性菌具有杀菌活性。作者报道了在29例中性粒细胞减少伴发热成人肿瘤患者中进行达托霉素的药动学研究结果。给予29例中性粒细胞减少伴发热肿瘤患者单剂30min内静脉滴注达托霉素6mg／kg,并分别留取用药前及用药结束后0、0．5、1、2、4、8、12和24h血样。     

Serum cardiac troponin T levels as an indicator of myocardial injury in ischemic and hemorrhagic stroke patients

Many studies in the literature have clearly shown the increase in creatine kinase-myocardial subfraction (CK-MB) levels and changes in electrocardiography (ECG) after stroke. However, the studies on cardiac troponin T (cTnT) which is more sensitive and specific to myocardium after stroke are relatively scarce. Moreover, its associations with volume of stroke lesions and type of stroke have not been investigated thoroughly. Thus, the aims of this study were to investigate a predictive value of cTnT in assessing myocardial injury and cardiac dysfunction in different types of stroke (hemorrhagic or ischemic stroke) and its relationship with stroke size and volume. This study included 62 patients (30 males and 32 females) with acute stroke confirmed by computed tomography (CT). Blood samples were obtained within 24 hours of stroke onset to measure the serum levels of creatin kinase (CK), CK-MB, lactate dehydrogenate (LDH), and cTnT. ECG and echocardiography were performed to assess myocardial function and left ventricular ejection fraction (LVEF). Of all patients included in the study, 20 patients (32%) demonstrated elevations in cTnT, while 28 patients (45%) had increased CK-MB levels. Serum levels of cTnT were positively correlated with stroke volume (r = 0.65, p < 0.0001), while inversely correlated with LVEF (r = -0.53, p < 0001). Serum levels of both CK-MB and cTnT were higher in patients with hemorrhagic stroke than those with ischemic stroke but this difference was not significant (p > 0.05). As a conclusion, cTnT has a higher specificity and sensitivity in detecting myocardial injury after stroke of both ischemic and hemorrhagic origins. Measurement of the serum levels of cTnT is of clinical importance in evaluating myocardial injury and provides a useful aid in estimating the volume of stroke lesions.