Specific biochemical markers of bone metabolism and cytokine study confirm the diagnosis of malignant infantile osteopetrosis at birth using cord blood sample

AIMS: To investigate the serum creatine kinase isoenzyme pattern, specific biochemical markers of bone metabolism, and cytokines in a Chinese family with osteopetrosis, and correlate abnormalities with the pathophysiology of this condition. METHODS: A Chinese female baby was diagnosed with malignant infantile osteopetrosis at the age of 3 weeks by clinical history and biochemical investigations. We studied the laboratory and radiological manifestations of this index case and her family members. RESULTS: Serum CK-BB fraction of our index patient was elevated to 18.0% (normal 1.6-7.6%). Her biochemical markers of bone resorption including serum C-terminal telopeptide concentration and urine N-terminal telopeptide to creatinine ratio were decreased to 0.54 microg/L (normal 0.72-1.56 microg/L) and 159 x 10(-6) (normal 372-900 x 10(-6)), respectively. Serum cytokines including soluble receptor activator of nuclear factor kappa-B ligand (sRANKL) concentration was suppressed to 0.11 pmol/L (normal 0.23-0.82 pmol/L) and osteoprotegerin (OPG) concentration was 4.9 pmol/L (normal 2.8-4.9 pmol/L), resulting in an elevated OPG to sRANKL ratio of 44.5 (normal 3.8-19.4) in favour of bone formation. CONCLUSIONS: If left untreated, this condition is usually fatal within the first year of life. With early diagnosis, management including bone marrow transplantation can be planned ahead and will result in a better survival.     

An improved method for utilization of peptide substrates for antibody characterization and enzymatic assays

Synthetic peptides have become an important tool in antibody production and enzyme characterization. The small size of peptides, however, has hindered their use in assays systems, such as Western blots, and as immunogens. Here, we present a facile method to improve the properties of peptides for multiple applications by ligating the peptides to intein-generated carrier proteins. The stoichiometric ligation of peptide and carrier achieved by intein-mediated protein ligation (IPL) results in the ligation product migrating as a single band on a SDS-PAGE gel. The carrier proteins, HhaI methylase (M.HhaI) and maltose-binding protein (MBP), were ligated to various peptides; the ligated carrier-peptide products gave sharp, reproducible bands when used as positive controls for antibodies raised against the same peptides during Western blot analysis. We further show that ligation of the peptide antigens to a different thioester-tagged carrier protein, paramyosin, produced immunogens for the production of antisera in rabbits or mice. Furthermore, we demonstrate the generation of a substrate for enzymatic assays by ligating a peptide containing the phosphorylation site for Abl protein tyrosine kinase to a carrier protein. This carrier-peptide protein was used as a kinase substrate that could easily be tested for phosphorylation using a phosphotyrosine antibody in Western blot analysis. These techniques do not require sophisticated equipment, reagents, or skills thereby providing a simple method for research and development.     

The effects of tibial rotation on patellar position

The effects of external and internal tibial rotation on patellar motion were investigated using a magnetic 3Space^® tracker system (Polhemus, Colchester, VT 05446, USA). Seven fresh-frozen adult cadaver knees were used in this study. The muscle alignment of each quadriceps muscle was measured to determine the direction of loading forces. Three loading patterns were used to simulate the unresisted knee extension during sitting, standing from squatting and the stance phase of walking, with different weights applied to each quadriceps muscle at each knee flexion angle. The position of the patella, along with patellar shift, tilt and rotation was measured and compared to external or internal tibial rotation and neutral rotation. In the sitting and squatting simulations the patella showed at the terminal extension of the knee more lateral shift and a more lateral tilt with tibial external rotation than in a neutral position (P < 0.05). In walking simulation, the patella showed more external rotation with external rotation of the tibia than with a neutral one, at the 0, 72 and 90% of the stance phase of walking (P < 0.05). These results demonstrate the importance of external tibial rotation as a factor in the development of patellar dislocations or subluxations, especially in athletes.     

Monocyte chemotactic protein-3 (MCP3) interacts with multiple leukocyte receptors: binding and signaling of MCP3 through shared as well as unique receptors on monocytes and neutrophils

The diversity of monocyte chemotactic protein (MCP)3 target cell types, as well as the capacity of MCP3 to desensitize leukocyte responses to other CC chemokines, suggested that MCP3 may interact with multiple CC chemokine receptors. The purpose of this study is to establish how MCP3 binds and activates monocytes and neutrophils. We show that human monocytes exhibit high-affinity binding for ¹²⁵I-MCP3 with an estimated Kd of 1–3 nM and about 10000 binding sites/cell. The binding of ¹²⁵I-MCP3 to monocytes was progressively less well competed by CC chemokines macrophage inflammatory protein (MIP)lα (Kd = 5–10 nM), RANTES (Kd = 5–10 nM), MCP1 (monocyte chemoattractant and activating factor, or MCAF) (Kd = 60 nM) and MIP1β (Kd > 100 nM). On the other hand, unlabeled MCP3 displaced the binding of radiolabeled MIP1α, RANTES, MCP1 and MIP1β as effectively as the isologous CC chemokines. In agreement with the binding data, pretreatment of monocytes with MCP3 completely desensitized the calcium flux in response to MIP1α and RANTES. However, MIP1α and RANTES failed to desensitize the response of monocytes to MCP3. MCP3 and MCP1 partially desensitized each other's effects on monocytes. These binding and cross-desensitization results suggest that MCP3 binds and signals through other binding sites in addition to those shared with MIP1α, RANTES and MCP1. The unidirectional competition for MIP1β binding and signaling by MCP3 suggests the existence of an as-yet unidentified site for MCP3 shared with MIP1β. The existence of another unique binding site(s) for MCP3 was further shown by the failure of any of the other CC chemokines to compete effectively for MCP3 binding on neutrophils. MCP3 in our study was also the only human CC chemokine that consistently chemoattracted neutrophils. These results suggest that MCP3 is a ligand that can bind and activate a broad range of target cells through receptors shared by other CC chemokines as well as its own receptor.     

Identification of testis development and spermatogenesis-related genes in human and mouse testes using cDNA arrays

We have constructed cDNA microarrays from the human testis large insert cDNA library, containing 9216 genes, together with several housekeeping genes. The cDNA microarrays were used to identify gene expression differences between human fetal and adult testes. Of >8700 hybridized clones, 731 exhibited significant differential expression characteristics. About 7500 genes were identified when the same cDNA microarrays were used for hybridization with cDNA probes from mouse testis, with 256 genes having significant differential expression between the age of 1-4 weeks. Among these genes, 101 were identified as critically related to testis development and possibly to spermatogenesis since they were found in both human and mouse testes, and expressed differentially at different stages of testis development. Of the 101 development-related genes, 59 full-length cDNAs have been sequenced previously, while the full-length cDNAs of the other 42 genes have not been published. We have obtained 11 full-length sequences of the 42 genes and deposited them in the GenBank. The conserved testis development-related genes found in both human and mouse testes may include genes that are likely to be involved in testicular functions, especially spermatogenesis, thus providing a basis for further functional characterization of the genes in mouse models.     

Functional magnetic resonance imaging evidence for binocular interactions in human visual cortex

Using functional magnetic resonance imaging (fMRI), we explored the binocular interactions occurring when subjects viewed dichoptically presented checkerboard stimuli. A flickering radial checkerboard was presented to each eye of the subject, while T2*-weighted images were acquired over the visual cortex with gradient-echo, echoplanar sequences. We compared responses in striate and extrastriate visual cortex under four conditions: both eyes were stimulated at the same time (binocular condition), each eye was stimulated in alternation (monocular condition) or first the one eye then the other eye was stimulated (left eye first - right eye trailing, or vice versa). The results indicate that only the striate area, in and near the calcarine fissure, shows significant differences for these stimulation conditions. These differences are not evident in more remote extrastriate or associational visual areas, although the BOLD response in the stimulation-rest comparison was robust. These results suggest that the effect could be related to inhibitory interactions across ocular dominance columns in striate visual cortex.     

汉族男子体格及生殖器发育特点

2411例汉族男性大学生体格和生殖器的测量结果如下:阴茎周径8.17±0.64cm,阴茎长度7.43±1.04cm,阴茎牵长13.33±1.19cm,右睾丸容积17.91±4.09ml,左睾丸容积17.83±4.05ml,身高171.07±5.66cm,体重58.43±7.75kg.北方学生体格和生殖器发育均优于南方.城、县、乡学生的生殖器发育无明显差异,但城市学生体格发育优于农村.16岁后阴茎、睾丸大小变化不大,但生殖器的发育可持续到30岁.     

布氏显微镜活血分析: 细胞流变学研究的新方法

布氏显微镜活血分析：细胞流变学研究的新方法骆秉铨＊黄荣国＊陈兴新＊细胞流变学是研究血细胞流动变形的科学，在方法学上发展了一些比较成熟的方法，但多不能直接动态观察细胞水平的真实改变，有待完善和创新。我们采用布氏多功能显微镜的活血分析法［１］，在高放大倍...     

Novel micro-crosslinked poly(organophosphazenes) with improved mechanical properties and controllable degradation rate as potential biodegradable matrix

As biodegradable materials, linear polyphosphazenes undergo rapid hydrolysis degradation but exhibit poor mechanical properties. Blending with biodegradable polyesters or inorganic particles strengthen their mechanical properties but give rise to slower degradation rate. To balance the mechanical properties and the degradation rate, micro-crosslinked polyphosphazenes were synthesized in this study. Their glass transition temperatures, mechanical properties, and in vitro degradation behavior were investigated. 2-hydroxyethyl methacrylate (HEMA) was firstly attached to the side chain along with glycine ethyl ester to prepare co-substituted poly(organophosphazene) with pendant ethenyl substituents. The co-substituted poly(organophosphazene) was blended with HEMA or acrylic acid (AA) followed by a free radical polymerization to prepare micro-crosslinked poly(organophosphazenes). The resulting crosslinked polymers showed two separate glass transition temperatures depending on the HEMA or AA feed. Incorporation of crosslinking affected the mechanical properties positively. Crosslinked poly(organophosphazenes) showed an approximately 11-17 fold increase in terms of modulus of elasticity when compared to the linear counterpart. In vitro degradation tests indicated that HEMA-crosslinked polymers hydrolyzed at a retarded rate while AA-crosslinked polymers hydrolyzed at a moderate rate compared to linear polymers.