Leptin transport at the blood–cerebrospinal fluid barrier using the perfused sheep choroid plexus model

Leptin is secreted by adipose tissue and thought to regulate appetite at the central level. Several studies have explored the central nervous system (CNS) entry of this peptide across the blood–brain and blood–cerebrospinal fluid (CSF) barriers in parallel, but this is the first to explore the transport kinetics of leptin across the choroid plexus (blood–CSF barrier) in isolation from the blood–brain barrier (BBB). This is important as the presence of both barriers can lead to ambiguous results from transport studies. The model used was the isolated Ringer perfused sheep choroid plexus. The steady-state extraction of [¹²⁵I]leptin (7.5 pmol l⁻¹) at the blood face of the choroid plexus was 21.1±5.7%, which was greater than extraction of the extracellular marker, giving a net cellular uptake for [¹²⁵I]leptin (14.0±3.7%). In addition, trichloroacetic acid precipitable [¹²⁵I] was detected in newly formed CSF, indicating intact protein transfer across the blood–CSF barrier. Human plasma concentrations of leptin are reported to be 0.5 nM. Experiments using 0.5 nM leptin in the Ringer produced a concentration of leptin in the CSF of 12 pM (similar to that measured in humans). [¹²⁵I]Leptin uptake at the blood–plexus interface using the single-circulation paired tracer dilution technique (uptake in <60 s) indicated the presence of a saturable transport system, which followed Michaelis–Menten-type kinetics (K_m=16.3±1.8 nM, V_max=41.2±1.4 pmol min⁻¹ g⁻¹), and a non-saturable component (K_d=0.065±0.002 ml min⁻¹ g⁻¹). In addition, secretion of new CSF by the choroid plexuses was significantly decreased with leptin present. This study indicates that leptin transport at the blood–CSF barrier is via saturable and non-saturable mechanisms and that the choroid plexus is involved in the regulation of leptin availability to the brain.     

抑制核小体结合蛋白1基因对人前列腺癌细胞LNCaP增殖的作用

目的利用RNA干扰（RNAi）技术,探讨核小体结合蛋白1（NSBP1）基因对人激素依赖前列腺癌细胞系LNCaP增殖的作用。方法设计并合成针对NSBP1的4种小分子干扰RNA（siRNA）（包含1种阴性对照）,构建能抑制NSBP1 mRNA表达的重组pSilencer 2．1-U6 neo质粒,转染LNCaP细胞。应用逆转录聚合酶链反应（RT-PCR）、Western印迹实验检测不同质粒对NSBP1表达的抑制效率,选取抑制效率最高的质粒转染LNCaP细胞,用四甲基偶氮唑盐（MTT）法测定细胞增殖活性,用流式细胞光度术检测细胞周期的变化。结果筛选出抑制效率最高的质粒pSilencer-81（mRNA水平抑制80％,蛋白水平抑制85％）,与阴性对照pSilencer-Neg质粒分别转染LNCaP细胞。转染60h后,经过84h、108h,一直到132h,LNCaP／81细胞A值（代表细胞活性）低于LNCaP／Neg细胞A值,差异均有统计学意义（t=4．501,4．282,5．229,4．759,均P〈0．05）。抑制率随时间延长而增加,在84h有所降低,在108h达最大值30．2％。转染60h后,经过84h,一直到108h,LNCaP／81细胞的G2M＋S期细胞百分率较LNCaP／Neg细胞的降低,差异均有统计学意义（t=3．705,3．887,8．220,均P〈0．05）。结论针对NSBP1的siRNA通过抑制前列腺癌LNCaP细胞中NSBP1基因的表达,能明显抑制细胞的增殖,NSBP1可能参与前列腺癌细胞生长增殖过程。     

Pharmacokinetics and tissue distribution of intraperitoneal 5-fluorouracil with a novel carrier solution in rats

AIM： To compare the pharmacokinetics and tissue distribution of 5-fluorouracil administered intraperitoneally with two isotonic carrier solutions： HAES-steri （neotype 6% hydroxyethyl starch）, a novel carrier solution with middle molecular weight and physiologic saline （0.9% sodium chloride solution）, a traditional carrier solution for intraperitoneal chemotherapy, in rats. METHODS： A total of 60 Sprague Dawley rats were randomized into groups according to the carrier solution administered. Each group was further randomized according to the intraperitoneal dwell period （1, 3, 6, 12, 18 and 24 h）. At the end of the procedure the rats were killed, the peritoneal fluid was withdrawn completely and quantitated. Drug concentrations in peritoneal fluid, plasma, and tissues were determined by high- performance liquid chromatography. RESULTS： The mean volumes remaining in the peritoneal cavity were significantly higher with HAES- steri than those with physiologic saline at 1, 6, 12, 18, and 24 h （P = 0.047, 0.009,0.005, 0.005 and 0.005 respectively, the percentages of remaining peritoneal fluid volume were 89.9 ± 5.6 vs 83.4 ± 4.9, 79.9 ± 2.8 vs 56.2 ± 15.7, 46.8 ± 5.5 vs 24.7 ± 9.7, 23.0 ± 2.8 vs 0.0 ± 0.0 and 4.2 ± 1.7 vs 0.0 ± 0.0 respectively）. Mean concentrations in peritoneal fluid were significantly higher with HAES-steri than those with physiologic saline at 3, 12 and 18 h （P = 0.009, 0.009 and 0.005 respectively, the concentrations were 139.2768 ± 28.2317 mg/L vs mg/L, 11.5427 ± 3.0976 mg/L vs 0.0000 ± 0.0000 mg/L and 4.7724 ± 1.0936 mg/L vs 0.0000 ± 0.0000 mg/L respectively）. Mean plasma 5-fluorouracil concentrations in portal vein were significantly higher with HAES-steri at 3, 12, 18 and 24 h （P = 0.009, 0.034, 0.005 and 0.019 respectively, the concentrations were 3.3572 ± 0.8128 mg/L vs 0.8794 ± 0.2394 mg/L, 0.6203 ± 0.9935 mg/L vs 0.0112 ± 0.0250 mg/L, 0.3725 ± 0.3871 mg/L vs 0.0000 ± 0.0000 mg/L, and 0.2469 ± 0.1457 mg/L vs 0.0000 ± 0.0000 mg/L respective     

合肥地区2011年健康人群流行性脑脊髓膜炎带菌率调查与分析

目的了解2011年合肥地区健康人群流行性脑脊髓膜炎带菌状况,为制定流脑的防控措施提供依据。方法按分层整群抽样方法,在全市范围于流脑流行前期采集6个年龄组健康人群咽拭子666份,现场接种于卵黄双抗琼脂培养基进行脑膜炎奈瑟氏菌分离培养,对可疑菌落进行生化和血清学鉴定。结果咽拭子脑膜炎奈瑟氏菌阳性检出31份,带菌率4.65%;菌株分别为A、B、C、D、X群,其中A群14株、B群12株,带菌率分别为45.16%、38.71%,C群3株,带菌率为9.68%,D、X群各1株。12～15岁儿童流脑带菌率最高,为10.00%,各年龄组带菌率差异有统计学意义(χ2=13.06,P<0.05)。男性带菌率5.49%、女性带菌率3.75%,城区人群带菌率4.98%、农村人群带菌率4.47%,差异均无统计学意义。结论合肥市健康人群流脑带菌率为4.65%,12～岁组人群流脑带菌率较高,警惕A群流脑菌群的流行。     

Neue Möglichkeiten in der Konduktorinnendiagnostik der Hämophilie A

Summary Hemophilia A is the most common inherited bleeding disorder in man. The recent isolation of the hemophilia gene has led to the identification of an intragenic restriction fragment length polymorphism (RFLP) which can be used for segregation analysis in families at risk for carrying the disease. In addition, a tightly linked extragenic RFLP can also be used for these analyses. In this paper, we exemplify the usefulness of DNA analysis in genetic counseling of families at risk for hemophilia A. Although DNA analysis allows carrier detection in the majority of families, bioassays are still required for accurate diagnosis when DNA analysis is not informative.

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Abkürzungen DNA Desoxyribonukleinsäure - RFLP Restriktionsfragmentlängenpolymorphismus     

固定化血红蛋白氧载体的研究 I.聚乙烯醇包埋血红蛋白

固定化血红蛋白可以作为氧载体，从海水中提取氧气，为人类在水下活动提供氧源。以聚乙烯醇为载体材料，固定化血红蛋白，制备氧载体。研究了该氧载体的氧解离性能以及戊二醛和六磷酸肌醇对氧载体氧解离性能的影响。血红蛋白的固定量达０．６ｇ／ｇ，氧化法测得氧载体的氧解离率为５３．３％。戊二醛后交联提高了氧载体的稳定性。六磷酸肌醇使氧解离率由２４．８％提高到６０．０％。     

Carrier Detection in Agammaglobulinemia by X Chromosome Inactivation Analysis

Using a recently developed strategy to analyze patterns of X chromosome inactivation in cell populations, we found that two mothers and a sister were carriers in three atypical or sporadic cases of patients with agammaglobulinemia, two of whom were brothers. In this study, a phosphogiycerate kinase 1 (PGK1) gene probe was used to detect patterns of methylation of X-chromosome genes. A random pattern of X inactivation was observed in isolated peripheral blood granulocytes. In contrast, one of the two X chromosomes was preferentially active in the Epstein-Barr virus (EBV)-transformed peripheral B cells of the family members of these patients. The volume of the blood specimen could be significantly reduced using EBV-transfomed B cell lines which contained multiple clones. The analysis described here can be used to distinguish between X-linked agammaglobulinemia (XLA) and other forms of a- or hypogammaglobulinemia as well as to detect the carrier state.     

rhBMP-2 injected in a calcium phosphate paste (alpha-BSM) accelerates healing in the rabbit ulnar osteotomy model.

This study evaluated the ability of recombinant human bone morphogenetic protein-2 (rhBMP-2) delivered in an injectable calcium phosphate carrier (alpha-BSM) to accelerate healing in a rabbit ulna osteotomy model compared to untreated surgical controls. Healing was assessed by radiography, histology and biomechanics. Bilateral mid-ulnar osteotomies were created in 16 skeletally mature rabbits. One limb in each animal was injected with either 0.1 mg rhBMP-2/alpha-BSM (BMP) (N=8) or buffer/alpha-BSM (BSM) (N=8). Contralateral osteotomies served as untreated surgical controls (SXCT). Gamma scintigraphy showed 75%, 45% and 5% of the initial 125I-rhBMP-2 dose was retained at the osteotomy site at 3 h, 1 week and 3 weeks. The biological activity of rhBMP-2 (alkaline phosphatase activity from bioassay) extracted from alpha-BSM incubated in vitro up to 30 days at 37 degrees C was unchanged. Radiographs demonstrated complete bridging of the BMP limbs at 4 weeks whereas none of the BSM or SXCT limbs were bridged. Post-mortem peripheral quantitative computed tomography determined mineralized callus area was 62% greater in BMP limbs compared to SXCT limbs. Torsional stiffness and strength were 63% and 103% greater in BMP limbs compared to SXCT limbs. There was no difference in torsional properties between BSM and SXCT limbs. Failure occurred outside the osteotomy in four out of seven of the BMP limbs. All BSM and SXCT limbs failed through the osteotomy. Histology showed bony bridging of the osteotomy and no residual carrier in the BMP limbs. BSM and SXCT groups showed less mature calluses composed of primarily fibrocartilaginous tissue and immature bone in the osteotomy gap. These data indicate rhBMP-2 delivered in alpha-BSM accelerated healing in a rabbit ulna osteotomy model compared to BSM and SXCT groups.     

Effects of reduction of carrier gas flow rate on sevoflurane and isoflurane consumption and costs

Purpose To evaluate whether sevoflurane and isoflurane consumption would be actually halved by halving the carrier gas flow rate, as predicted by a theoretical model, we measured the consumed volume of liquid sevoflurane and isoflurane and total costs of anesthetic gas at carrier gas flow rates of 3 and 61·min⁻¹. Methods Eighty patients of ASA physical status I or II were randomly assigned to one of four groups: sevoflurane at 3 or 61·min⁻¹ and isoflurane at 3 or 61·min⁻¹. Anesthesia was induced with thiamylal and maintained with sevoflurane or isoflurane, as well as with nitrous oxide in oxygen. The consumption of sevoflurane and isoflurane was measured by weighing the bottle of liquid agent, which was greater in the groups receiving 61·min⁻¹ gas than in those receiving 31·min⁻¹. Results Halving the carrier gas flow rate reduced the consumption of sevoflurane by 41.8% and that of isoflurane by 52.6%. It also reduced the total cost by 44.3% for sevoflurane and 49.2% for isoflurane. Conclusion Halving the carrier gas flow rates halved the consumption of isoflurane but not of sevoflurane, indicating that factors other than carrier gas flow rates are involved in determining consumption in the clinical setting.