Pharmacological Characterization of Bradykinin Receptors Coupled to Phosphoinositide Turnover in SV40-Immortalized Human Trabecular Meshwork Cells

This study sought to pharmacologically characterize bradykinin receptors on SV40-immortalized human trabecular meshwork (HTM3) cells. Phosphoinositide (PI) turnover studies were conducted using [³H]myo-inositol-labeled HTM3 cells and anion exchange chromatography to quantify [³H]inositol phosphates generated in response to bradykinin (BK) and various BK analogs. The blockade of these responses was studied using two potent and receptor-subtype selective antagonists. BK and T-kinin (Ile-Ser-BK; TK) induced a 4.2–4.4 fold stimulation of PI turnover above base levels at 1–10 μM. Several other peptides unrelated to BK, including angiotensin II, endothelin, cholecystokinin, bombesin and peptide YY tested at 1–10 μMwere essentially inactive. The molar potencies (EC₅₀) of BK, TK and close analogs were: BK=4.5±0.5 nM(n=6), Lys-BK=6.5±0.7 nM(n=3), TK=38.8±6.6 nM(n=8), Met-Lys-BK=41.5±13.4 nM(n=4), Des-Arg⁹-BK=2093±626 nM(n=4). All the latter BK-related peptides>were full agonists. The actions of BK and TK were potently and competitively antagonized by Hoe-140 (molar potency=0.6–1 nM;pA₂n=8.97–9.21,n=3–4) and byD-Arg⁰[Hyp³,-Thi^5,8,-DPhe⁷]-BK (molar potency=251 nM;-log potency, pK_b=6.6), two selective B₂-type BK antagonists. In conclusion, rank order of potency of BK agonists and the blockade of BK- and TK-induced PI turnover by the selective antagonists are consistent with the classification of the BK receptors on HTM3 cells as the B₂-receptor subtype.     

A Bayesian approach to subvoxel tissue classification in NMR microscopic images of trabecular bone

NMR microscopy is currently being used as an investigational tool for the evaluation of micromorphometric parameters of trabecular bone as a possible means to assess its strength. Since, typically, the image voxel size is not significantly smaller than individual trabecular elements, partial volume blurring can be a major complication for accurate tissue classification. In this paper, a Bayesian segmentation technique is reported that achieves improved subvoxel tissue classification. Each voxel is subdivided either into eight subvoxels twice the original resolution, or up to four subvoxels along the transaxial direction and the subvoxels optimally classified as either bone or marrow. Based on a statistical model for partial volume blurring, the likelihood for the number of marrow subvoxels in each voxel can be computed on the basis of its measured signal. To resolve the ambiguity of the location of the marrow subvoxels, a Gibbs distribution is introduced to model the interaction between the subvoxels. Neighboring subvoxel pairs with the same tissue label are encouraged, and pairs with distinct labels are penalized. The segmentation is achieved by maximizing the a posteriori probability of the label image using the block ICM (iterative conditional mode) algorithm. The potential of the proposed technique is demonstrated in real and synthetic NMR microscopic images.     

The skeleton as a unique environment for breast cancer cells

Bone is a favored location for several cancer metastases especially breast, prostate and myeloma. This review evaluates various properties of the skeleton that contribute to its successful colonization by breast cancer cells. The first consideration is the unique aspects of the vasculature of metaphyseal bone, which may account for the initial lodging of breast cancer cells in specific regions of the skeleton. Metasphyseal bone, found at the ends of long bone, in ribs and in vertebrae, is comprised of trabecular bone interspersed with marrow and a rich vasculature. The chemotactic factors that arise from bone marrow and bone cells are discussed in terms of cancer cell migration out of the vasculature and entry of cancer cells into the marrow cavity. Once the breast cancer cells have migrated into the metaphysis, they interact both directly and indirectly with bone cells and other cells in the marrow. As tumor growth progresses, functional bone cells are lost, most likely through apoptosis. This revised version was published online in July 2006 with corrections to the Cover Date.     

人眼小梁细胞体外表达表皮生长因子mRNA和表皮生长因子受体

目的 了解培养的小梁细胞分泌表皮生长因子（ｅｐｉｄｅｒｍａｌ ｇｒｏｗｔｈ ｆａｃｔｏｒ,ＥＧＦ）及细胞膜上表皮生长因子受体（ｅｐｉｄｅｒｍａｌ ｇｒｏｗｔｈ ｆａｃｔｏｒ ｒｅｃｅｐｔｏｒ,ＥＧＦＲ）的情况。方法 进行人眼小梁细胞体外培养。用ＥＧＦ ｃＤＡＮ探针,α＾－３２ｐ同位素标记及斑点杂交放射自显影法,检测小梁细胞分泌ＥＧＦｍＲＮＡ的情况。结果 人眼小梁细胞体外培养成功。免疫组化染色显示小     

压力对体外培养牛眼小梁细胞的影响

目的 观察压力对小梁细胞的影响。方法 对体外培养牛眼小梁细胞施以不同程度的压力,用倒置相差显微镜、光镜、电镜观察细胞形态结构及吞噬功能的变化。结果 细胞承受２．００ｋｐａ（１ｋｐａ＝７．５ｍｍＨｇ）、２．６７ｋｐａ压力４８小时,各项指标与对照组比较,差异无显著性。４．００ｋｐａ２４小时,细胞形态结构有轻度的损伤,吞噬功能有轻度下降。当压力进一步增加,时间更加延长后,细胞的损伤也更重。结论小梁细胞只     

地塞米松对小梁细胞粘附及吞噬功能的影响

目的：探讨地塞米松对小梁细胞的粘附及吞噬功能的影响。方法：不同浓度地塞米松(10^-7M，10^-6M，10^-5M)处理体外培养的牛眼小梁细胞3d，消化、漂洗后加入用不同的细胞外基质(Extracellular matrix，ECM)包被的培养板中，37℃孵育90min后．采用甲基噻唑基四唑(Methyl thiazolyl tetrazolium，MW)法测定各组吸光度值反应粘附细胞的量；另外，以乳胶微球为标记，观察不同浓度的地塞米松对小梁细胞吞噬功能的影响。结果：与对照组比较，三种浓度的地塞米松均对小梁细胞与ECM粘附有抑制作用．且呈浓度依赖性；对小梁细胞的吞噬功能亦呈现浓度依赖性抑制作用。结论：地塞米松对小梁细胞的粘附及吞噬功能有抑制作用，抑制小梁细胞的粘附及吞噬功能可能是皮质类固醇性青光眼的发病原因之一。     

不同植入物在非穿透小梁手术的临床观察

目的探讨不同植入物在非穿透小梁手术(NPTS)中治疗开角型青光眼的临床疗效。方法将40例(54眼)原发开角型青光眼随机分为A、B、C三组,每组均为18眼。A组:NPTS+HealonGV植入。B组:NPTS+保存羊膜植入。C组:NPTS+透明质酸钠生物胶(SK-GEL)植入。术中全部眼联合丝裂霉素C及可调缝线,观察术后眼压、视力、滤过泡、前房、视野等。结果随访6～18个月,平均(9.32±4.81)个月,手术成功率:A组55.56%,B组88.89%,C组94.44%,B、C组与A组比较差异有统计学意义(P<0.05),而B和C两组间差异无统计学意义(P>0.05)。三组患者无前房变浅、炎症、脉络膜脱离、视力下降等并发症。结论NPTS植入物中SK-GEL及羊膜最好,HealonGV次之,羊膜更经济。     

IL-6对体外培养的牛眼小梁细胞中纤维连接蛋白的影响

目的：探讨不同浓度白细胞介素-6(IL-6)刺激下体外培养的牛眼小梁细胞中纤维连接蛋白的表达变化。

方法：采用组织块培养法取新鲜牛眼的小梁网组织,提取并培养第3代牛眼小梁细胞,采用细胞形态学对细胞进行鉴定。经终浓度为0、0.1、0.5、1ng/mL的IL-6药物刺激24h后,采用荧光定量PCR和蛋白质免疫印迹法检测各浓度IL-6刺激下牛眼小梁细胞中FN mRNA和蛋白的表达。

结果：培养出的牛眼小梁细胞符合第3代牛眼小梁细胞形态特征。实时荧光定量PCR和蛋白质免疫印迹法显示,不同浓度IL-6刺激下的牛眼小梁细胞所产生的FN mRNA量分别为1.000±0.000、0.213±0.004、0.056±0.001、0.019±0.002,FN蛋白表达量分别为1.167±0.012、0.662±0.009、0.238±0.011、0.061±0.011,均呈下调趋势(r_s=-0.713、-0.901,均P<0.05),4组间FN mRNA和蛋白表达均有差异(P<0.05)。

结论：体外培养的牛眼小梁细胞在外源性IL-6刺激下影响FN mRNA和蛋白的表达,且IL-6浓度与蛋白表达呈负相关性,推测IL-6可能通过影响FN基因与蛋白的表达,进而改变小梁网组织结构。     

Myopathy associated with homozygous PYROXD1 pathogenic variants detected by genome sequencing

Biallelic pathogenic variants in the gene PYROXD1 have recently been described to cause early-onset autosomal recessive myopathy. Myopathy associated with PYROXD1 pathogenic variants is rare and reported in only 17 individuals. Known pathogenic variants in PYROXD1 include missense, insertion and essential splice-site variants. Here we describe a consanguineous family of individuals affected with late-onset myopathy and homozygous PYROXD1 missense variants (NM_024854.5:c.464A>G [p.Asn155Ser]) expanding our understanding of the possible disease phenotypes of PYROXD1-associated myopathy.     

Creation of an Age-Adjusted,Dual-Energy X-ray Absorptiometry–Derived Trabecular Bone Score Curve for the Lumbar Spine in Non-Hispanic US White Women

The trabecular bone score (TBS, Med-Imaps, Pessac, France) is an index of bone microarchitecture texture extracted from anteroposterior dual-energy X-ray absorptiometry images of the spine. Previous studies have documented the ability of TBS of the spine to differentiate between women with and without fractures among age- and areal bone mineral density (aBMD)-matched controls, as well as to predict future fractures. In this cross-sectional analysis of data collected from 3 geographically dispersed facilities in the United States, we investigated age-related changes in the microarchitecture of lumbar vertebrae as assessed by TBS in a cohort of non-Hispanic US white American women. All subjects were 30 yr of age and older and had an L1–L4aBMDZ-score within ±2 SD of the population mean. Individuals were excluded if they had fractures, were on any osteoporosis treatment, or had any illness that would be expected to impact bone metabolism. All data were extracted from Prodigy dual-energy X-ray absorptiometry devices (GE-Lunar, Madison, WI). Cross-calibrations between the 3 participating centers were performed for TBS and aBMD. aBMD and TBS were evaluated for spine L1–L4 but also for all other possible vertebral combinations. To validate the cohort, a comparison between the aBMD normative data of our cohort and US non-Hispanic white Lunar data provided by the manufacturer was performed. A database of 619 non-Hispanic US white women, ages 30–90 yr, was created. aBMD normative data obtained from this cohort were not statistically different from the non-Hispanic US white Lunar normative data provided by the manufacturer (p = 0.30). This outcome thereby indirectly validates our cohort. TBS values at L1–L4 were weakly inversely correlated with body mass index (r = −0.17) and weight (r = −0.16) and not correlated with height. TBS values for all lumbar vertebral combinations decreased significantly with age. There was a linear decrease of 16.0% (−2.47 T-score) in TBS at L1–L4 between 45 and 90 yr of age (vs. −2.34 for aBMD). Microarchitectural loss rate increased after age 65 by 50% (−0.004 to −0.006). Similar results were obtained for other combinations of lumbar vertebra. TBS, an index of bone microarchitectural texture, decreases with advancing age in non-Hispanic US white women. Little change in TBS is observed between ages 30 and 45. Thereafter, a progressive decrease is observed with advancing age. The changes we observed in these American women are similar to that previously reported for a French population of white women (r² > 0.99). This reference database will facilitate the use of TBS to assess bone microarchitectural deterioration in clinical practice.