Haplotype analysis of the Mexican frameshift Cd 11 (−T) and −28 A→C β-thalassemia alleles

The origins of the −28 A→C and frameshift Cd 11 −T (Fs Cd 11 −T) alleles were investigated by β-globin cluster haplotype analysis. These alleles were found in a Mexican mestizo family with β-thalassemia (β-thal). The -28 A→C mutation was described previously in Kurdish Jews linked to the most common haplotype in the world (+−−−−++), the same haplotype observed in this Mexican family. Therefore, it is not possible to assess a new origin of the −28 A→C mutation in our population. The Fs Cd 11 −T allele, not reported to date in any other populations, was linked to the −++−−+− haplotype (sixth in frequency in the world). This haplotype has not been reported in association with any β-thal mutant, suggesting a Mexican origin for the Cd 11 −T mutation. © 1995 Wiley-Liss, Inc.     

Neuronal lactate levels depend on glia-derived lactate during high brain activity in Drosophila

Lactate/pyruvate transport between glial cells and neurons is thought to play an important role in how brain cells sustain the high-energy demand that neuronal activity requires. However, the in vivo mechanisms and characteristics that underlie the transport of monocarboxylates are poorly described. Here, we use Drosophila expressing genetically encoded FRET sensors to provide an ex vivo characterization of the transport of monocarboxylates in motor neurons and glial cells from the larval ventral nerve cord. We show that lactate/pyruvate transport in glial cells is coupled to protons and is more efficient than in neurons. Glial cells maintain higher levels of intracellular lactate generating a positive gradient toward neurons. Interestingly, during high neuronal activity, raised lactate in motor neurons is dependent on transfer from glial cells mediated in part by the previously described monocarboxylate transporter Chaski, providing support for in vivo glia-to-neuron lactate shuttling during neuronal activity.     

富血小板血浆对人骨髓间充质干细胞成骨分化的抑制效应

目的:一些理论质疑富血小板血浆对骨前体细胞成骨分化的作用,本实验拟验证富血小板血浆对体外培养的人骨髓间充质干细胞成骨分化的抑制效应。方法:实验于2005-05/11在南方医科大学组织工程试验室(省级)完成。①实验方法:抽取6名健康志愿者髂前上棘骨髓5mL进行体外细胞培养扩增,静脉血10mL以二次离心法制得富血小板血浆。诱导骨髓间充质干细胞时富血小板血浆与骨髓间充质干细胞均来自同一个体。②碱性磷酸酶染色:取第4代骨髓间充质干细胞,分为两组:富血小板血浆组加入富血小板血浆使终浓度为100g/L,单纯血清培养组仅加入等量胎牛血清。培养后第7天进行碱性磷酸酶染色,阳性细胞为胞质中呈现黑色颗粒或块状沉淀。③矿化结节染色:取第4代骨髓间充质干细胞,分组同上。培养后第19天以0.1%茜素红-TrisHcl(pH8.3)37℃下放置30min,矿盐沉积染色阳性为红色。④Cbfa1基因表达:取第4代骨髓间充质干细胞,分组同上。培养后第3,7,12,16天RT-PCR法检测骨髓间充质干细胞Cbfa1基因的表达。⑤形态学观察:实验过程中使用相差显微镜观察各组细胞生长情况及形态学变化。结果:①骨髓间充质干细胞碱性磷酸酶染色结果:培养后第7天,富血小板血浆组碱性磷酸酶阳性细胞数量较单纯血清培养组明显减少,且阳性细胞内灰黑色颗粒也明显减少,为弱阳性。②骨髓间充质干细胞矿化结节染色结果:培养后第19天,单纯血清培养组可见细胞表面有较多的矿盐沉积,但未形成明显的矿化结节。富血小板血浆组细胞表面只有稀少的矿盐沉积。③骨髓间充质干细胞cbfa1mRNA的表达:培养后第3,7,12,16天,随着培养时间的延长单纯血清培养组与富血小板血浆组cbfa1基因表达量均逐渐增高,同一时间点两组间cbfa1基因的表达基本相似。④骨髓间充质干细胞形态学变化:富血小板血浆组骨髓间充质干细胞增殖旺盛,细胞达到单层汇合的时间较单纯血清培养组明显缩短。单纯血清培养组细胞在完全汇合后开始出现聚合现象(14～16d),但趋向性不明显,未完全形成团簇;富血小板血浆组细胞在完全汇合后未出现聚合现象,细胞密集生长。培养初期两组细胞以梭形为主,多角形细胞较少,培养至14～16d单纯血清培养组多角形细胞较富血小板血浆组增多。结论:富血小板血浆可抑制人骨髓间充质干细胞碱性磷酸酶的分泌与矿盐沉积,对人骨髓间充质干细胞成骨分化的直接效应是抑制其分化。     

Lower extremity bone mineral density in children with congenital spinal dysfunction

Aim  To assess lower extremity bone mineral density (BMD) of children with congenital spinal dysfunction and examine factors that may influence BMD in this population. Method  Forty‐four children (25 females, 19 males) aged 6 to 18 years (mean 11y 11mo, SD 3y 6mo) with congenital spinal dysfunction (35 with myelomeningocele, seven with lipomas, one with sacral agenesis, one with caudal regression) were enrolled in the study. A health survey including ambulatory status, history of bladder augmentation, and history of fracture was administered. Each participant had a physical examination including Tanner stage and neurological level. Dual‐energy X‐ray absorptiometry scans of the lateral distal femur (LDF) and, when possible, lumbar spine were obtained. We reported LDF BMD results as z‐scores for three regions of interest (metaphyseal, metadiaphyseal, and diaphyseal). Univariable and multivariable analyses examined relationships between LDF BMD and the other variables. Results  BMD was significantly related to ambulatory status (14 non‐ambulatory, 15 partly ambulatory, 15 fully ambulatory) and neurological level (13 with low‐level lesions, 15 medium‐level, 16 high‐level) in the univariable analysis (p<0.01 for both in all three regions). Neither history of fracture, nor Tanner stage, nor history of bladder augmentation showed a significant relationship to BMD. The significance of ambulatory status and neurological level in the univariable analysis failed to persist in the multivariable analysis of this study with a small sample size. Interpretation  The LDF measurement proved to be a viable technique for assessing BMD in children with congenital spinal dysfunction. LDF BMD was sensitive to differences in three categories of ambulation. The overall influence of neurological level was not deemed as important as ambulation.     

Further development of a successful protocol of graft versus leukemia without fatal graft-versus-host disease in AKR mice.

We previously reported a successful model for treatment of BW 5147 leukemia in AKR mice by adoptive immunotherapy using allogeneic spleen cells from C57BL/6 mice. The leukemia cells were given 3 days before initiation of therapy. Graft-versus-host reaction was prevented by treatment with spleen cells from a second allogeneic strain (CBA), followed by cyclophosphamide and syngeneic spleen cells. We now show that it is not necessary to use syngeneic spleen cells in the final transplant since H-2-compatible, allogeneic CBA cells are as effective. In addition, it is possible to initiate successful therapy 5 days after leukemia implantation providing that the initial cyclophosphamide, given in two doses of 100 mg/kg each and spaced 7 days apart, is administered prior to establishment of graft-versus-host reaction. Higher single doses of drugs were followed by fatal graft-versus-host disease.     

Intracranial pressure in adult non-tumoral hydrocephalus.

Intracranial pressure (ICP) was monitored continuously for 48 hours in four patients with different types of non-tumoral adult hydrocephalus and classificated according to ICP recordings. It is emphasized that ICP monitoring is essential in the diagnosis of normal pressure hydrocephalus (NPH), since its possible to observe abnormal pressure recordings with morphological alterations which can be accompanied or not by periods of raised ICP. It is suggested that this method may help identify cases suitable for surgery.