Prevalence and distribution of sesamoid bones in the hand determined using digital tomosynthesis

The aim of this study was to identify the prevalence and distribution of sesamoid bones in the hand using digital tomosynthesis (DTS) in comparison to previous studies. Using conventional radiography (CR) and DTS, hand images (81 left and 100 right) taken at a tertiary hospital were retrospectively reviewed. The sesamoid bones were identified in the interphalangeal (IP) and metacarpophalangeal (MCP) joints of the thumb (I), and in the distal interphalangeal (DIP) and metacarpophalangeal (MCP) of index (II), middle (III), ring (IV), and little (V) fingers. Differences in number of sesamoid bones detected on CR and DTS were analyzed. Sesamoid bones were observed in MCP I (100%), MCP II (46%), MCP III (2%), MCP IV (2%), MCP V (53%), and IP I (53%) on CR. Using DTS, sesamoid bones were found more often in MCP I (100%), MCP II (54%), MCP III (2%), MCP IV (1%), MCP V (59%), and IP I (75%). Differences in the mean number of sesamoid bones detected on CR and DTS were statistically significant. Sesamoid bones in DIP joints were frequently observed on DTS, but rarely found on CR. Most sesamoid bones in the hand were detected in MCP I, II, V, and IP I joints, and were more often detected on DTS than CR. DTS is a reliable tool to evaluate bony structures in the hand. Clin. Anat. 30:608–613, 2017. © 2017 Wiley Periodicals, Inc.     

The prevalence of the sesamoid bones of the hand: A systematic review and meta‐analysis

The literature contains various estimates of the prevalence and distribution of the sesamoid bones in the hands. The aims of this systematic review are to provide a better estimate of the frequency of hand sesamoids and its association with variables such as ancestry, gender, and side. Nineteen studies met the inclusion criteria. The pooled rates of the sensitive meta‐analyses from large‐sample studies in adults showed: (a) true overall rates of 99.9% for the metacarpophalangeal (MCP) joint of the thumb (MCP‐I), 53% for the interphalangeal joint (IP‐I), 43.4% for the MCP of the index (MCP‐II), 1.47% for the MCP of the medius finger (MCP‐III), 0.6% for the MCP of the ring finger (MCP‐IV), and 67.7% for the MCP of the auricular finger (MCP‐V); (b) true radiological rates of 99.9% for the radial thumb sesamoid, 99.6% for the ulnar thumb sesamoid, 47.8% for IP‐I, 40% for MCP‐II, 1.3% for MCP‐III, 0.8% for MCP‐VI, and 62.8% for MCP‐V. Black, Middle Eastern, and European ancestries conferred significantly higher sesamoid frequencies at IP‐I, MCP‐II, and MCP‐V, respectively. There was a significant association with female gender at MCP‐II, MCP‐IV, and MCP‐V, with ORs of 1.53, 4, and 1.3, respectively, and a nonsignificant “female” trend for the other locations. There was no significant association with hand side. The pooled rates of hand sesamoids in children aged 10–17 years were 92.7, 42.2, 33.8, 0.5, 0.3, and 36.5% for MCP‐I, IP‐I, MCP‐II, MCP‐III, MCP‐IV, and MCP‐V, respectively. The findings of this evidence‐based anatomical review provide quantitative evidence that the incidence of sesamoid bones in human hands depends on genetic rather than functional factors. Clin. Anat. 27:1291–1303, 2014. © 2014 Wiley Periodicals, Inc.     

Identification and characterization of membrane cofactor protein (CD46) in the human kidneys

Membrane cofactor protein (MCP, CD46) is an integral protein that serves as a cofactor for factor I in inactivating C3b/C4b deposited on the same cell-membrane as C3bi/C4c+C4d. This C3b/C4b inactivation is closely associated with self-protection of host cells from autologous complement attack. We have studied the distribution and properties of MCP in the normal human kidney by immunohistochemical and immunoblotting methods using monoclonal antibodies against MCP. MCP was predominantly expressed on the juxtaglomerular apparatus. Glomerular capillary walls, mesangial areas, and tubulus were also MCP positive. Glomerulus MCP was composed of two major bands of 45–65 kDa, which were similar to those of lymphocyte MCP. The proportion of the high and low molecular weight components in glomerulus MCP, however, was considerably different from that of lymphocyte MCP among the individual samples tested. Glomerular epithelial cells and mesangial cells from an individual having equal amounts of high and low molecular weight components in the lymphocytes were cultured seperately and the properties of their MCP investigated. MCP in the mesangial cells and glomerular epithelial cells showed profiles in which the upper band was predominant. The results may explain the unique distribution of the high and low molecular weight forms in the glomerulus. These forms of MCP together with factor I were all capable of inactivating C3b to C3bi. Message analysis suggested that glomerular epithelial cells and mesangial cells synthesized a single species of mRNA of 4.2 kb from which the polymorphic MCP species were generated. Flow cytometric analysis suggested that MCP was minimal in mesangial cells. These results, taken together with the previous reports on the distribution of other complement regulatory proteins, infer that the distribution profile of MCP is rather similar to that of DAF but differs from those of CD59 and CR1 in the normal human kidney; this may reflect the differences between their roles or functional properties in renal tissue.     

Effect of sensory feedback from the proximal upper limb on voluntary isometric finger flexion and extension in hemiparetic stroke subjects

This study investigated the potential influence of proximal sensory feedback on voluntary distal motor activity in the paretic upper limb of hemiparetic stroke survivors and the potential effect of voluntary distal motor activity on proximal muscle activity. Ten stroke subjects and 10 neurologically intact control subjects performed maximum voluntary isometric flexion and extension, respectively, at the metacarpophalangeal (MCP) joints of the fingers in two static arm postures and under three conditions of electrical stimulation of the arm. The tasks were quantified in terms of maximum MCP torque [MCP flexion (MCP(flex)) or MCP extension (MCP(ext))] and activity of targeted (flexor digitorum superficialis or extensor digitorum communis) and nontargeted upper limb muscles. From a previous study on the MCP stretch reflex poststroke, we expected stroke subjects to exhibit a modulation of voluntary MCP torque production by arm posture and electrical stimulation and increased nontargeted muscle activity. Posture 1 (flexed elbow, neutral shoulder) led to greater MCP(flex) in stroke subjects than posture 2 (extended elbow, flexed shoulder). Electrical stimulation did not influence MCP(flex) or MCP(ext) in either subject group. In stroke subjects, posture 1 led to greater nontargeted upper limb flexor activity during MCP(flex) and to greater elbow flexor and extensor activity during MCP(ext). Stroke subjects exhibited greater elbow flexor activity during MCP(flex) and greater elbow flexor and extensor activity during MCP(ext) than control subjects. The results suggest that static arm posture can modulate voluntary distal motor activity and accompanying muscle activity in the paretic upper limb poststroke.     

Soft layered concept in the design of metacarpophalangeal joint replacement implants

The metacarpophalangeal (MCP) joint is crucial for hand function, but the joints are frequently affected by arthritis, leading to pain and disability. Joint replacement implants are used to replace the diseased MCP joint. This paper presents an investigation of applying the soft layered concept in the design of a new MCP joint replacement implant. Analytical methods were used to investigate the minimum film thickness for a novel MCP joint with a soft layer. The effect of load, entraining velocity, radial clearance, radius of the metacarpal head, elastic modulus and thickness of the soft layer were investigated. The soft layered joints show an enhanced predicted film thickness and some evidence of fluid film lubrication that should help to reduce wear rates. It may be beneficial for future MCP joint implant designs to utilise the soft layered joint concept.     

Activation of intrinsic and extrinsic finger muscles in relation to the fingertip force vector

Surface EMG was recorded from two intrinsic and two extrinsic muscles of the index finger during a two-dimensional isometric force task in the plane of flexion and extension. Subjects applied force isometrically at the fingertip in eight equally spaced directions, encompassing 360 degrees. Target forces spanned the range from 20% to 50% of maximum for each direction. The effect of varying the metacarpophalangeal (MCP) and interphalangeal (IP) joint angles was investigated. We found that when applying isometric force with the fingertip, the intrinsic muscles of the index finger behaved as a single unit whose region of activation overlapped that of the extrinsic flexor and extensor muscles. The activation region of the intrinsic muscles also spanned a range of force directions for which the extrinsic muscles were virtually inactive. The activation of all muscles, with the exception of the extrinsic extensor, was modified by changing the MCP and IP joint angles. Both IP flexion and MCP extension produced rotation of the resultant activity vector in the direction of MCP flexion. However, the relative rotation was much greater with IP flexion than MCP extension. The effect of IP flexion is linked to rotation of the force direction where joint torque switches from extension to flexion, while the effect of MCP extension is more likely related to changes in muscle length and MCP moment arm. Our results suggest that the primary role of intrinsic finger muscles is to precisely control the direction of fingertip force, while extrinsic muscles provide stability of the joints.     

Soluble forms of membrane cofactor protein (CD46, MCP) are present in plasma, tears, and seminal fluid in normal subjects.

We have established an ELISA for determination of membrane cofactor protein (MCP, CD46) both solubilized from cell membranes and released in body fluids. In this assay, mouse MoAbs against MCP, M177 and M160 whose epitopes were different, were used as capture and detection antibodies, respectively. The NP-40 concentration in samples for MCP to be measured must be less than 0.05%. The detection limit of this MCP assay was 0.5 ng. The assay was used to quantify solubilized membrane MCP, and soluble MCP in normal human plasma, serum, urine, saliva, tears, and seminal fluid, and culture media of tumour cell lines. Soluble MCP was barely detected in the conditioned media of the cell lines. The levels of sMCP in plasma and serum were 10-60 ng/ml and that in tears, 0-50 ng/ml. Seminal fluid contained about 10-fold more soluble MCP than serum. Soluble MCP was not detectable by this assay in the other body fluids, suggesting that their MCP levels were less than the detection limit, if any.     

Study on the capillary permeability of myocardium in diabetic rats]

The alteration of myocardial capillary permeability (MCP) in experimental diabetic rat was investigated by using cationic ferritin as a tracer. Diabetes was induced by injection of streptozocin (70mg/kg b.w.ip.). Vehicle injected, age and body weight-matched rats were served as the controls. The myocardial tissue was examined by the end of 2,7, and 9 months or even longer after diabetes induction. Results showed that (1) MCP was significantly increased in diabetic rats in comparing with that of the controls; (2) The increase of permeability became more pronounced with prolongation of the course of diabetes; and (3) the increase of MCP preceded the capillary basal laminar thickening demonstrated by electron microscopy. These findings suggest that increased MCP may play a role in the pathogenesis of basal laminar thickening and myocardial complications in diabetic state.     

Possible involvement of proteasome inhibition in aging: implications for oxidative stress

Oxidative stress may contribute to the cellular alterations, which occur as the result of aging, and the nervous system is particularly vulnerable to aging associated oxidative injury. The multicatalytic proteasome (MCP) is responsible for the majority of protein degradation and is sensitive to oxidative stress. To determine if MCP activity is altered during aging, studies were conducted in multiple tissues from aged Fisher 344 rats. Analysis of heart, lung, kidney, and liver revealed decreased MCP activity in 12, 24, and 28 month old rats, compared with 3 week or 3 month old animals. The spinal cord, hippocampus, and cerebral cortex demonstrated age dependent decreases in MCP activity, but at no timepoint was MCP activity decreased in either the brain stem or cerebellum. Oxidative injury and the lipid oxidation product 4-hydroxynonenal caused decreased MCP activity in neural PC6 cells, while application of MCP inhibitors was sufficient to induce cell death in neural PC6 cells. Together, these data indicate a role for MCP inhibition in cellular dysfunction associated with aging and oxidative injury.     

Epitope mapping of 10 monoclonal antibodies against the pig analogue of human membrane cofactor protein (MCP)

Pig membrane cofactor protein (MCP; CD46) is a 50 000-60 000 MW glycoprotein that is expressed on a wide variety of cells, including erythrocytes. Pig MCP has cofactor activity for factor I-mediated cleavage of C3b and is an efficient regulator of the classical and alternative pathway of human and pig complement. A panel of 10 monoclonal antibodies (mAbs) was collected from two different laboratories; all of these mAbs were raised against pig leucocytes and all recognized the same complex banding pattern on sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) of erythrocyte membranes. All were shown to be reactive with pig MCP and were divided into four groups of mutually competitive antibodies based on competition studies for membrane-bound MCP and for soluble MCP, the latter by surface plasmon resonance (SPR) analysis. The antigenic properties of membrane-bound and soluble MCP were similar, although some interesting differences were revealed. None of the 10 mAbs were cross-reactive with human MCP and only one showed cross-reactivity with leucocytes from a panel of large mammals - a weak cross-reactivity with a subset of dog leucocytes. All antibodies in one of the epitope groups and some in a second epitope group were able to block the functional activity of pig MCP, as measured by inhibition of MCP-catalysed C3 degradation by factor I.     

Implications of the initial mutations in membrane cofactor protein (MCP; CD46) leading to atypical hemolytic uremic syndrome

The hemolytic uremic syndrome is characterized by the triad of microangiopathic hemolytic anemia, thrombocytopenia and acute renal failure. There are two general types. One occurs in epidemic form and is diarrheal associated (D+HUS). It has a good prognosis. The second is a rare form known as atypical (aHUS), which may be familial or sporadic, and has a poor prognosis. aHUS is increasingly recognized to be a disease of defective complement regulation, particularly cofactor activity. Mutations in membrane cofactor protein (MCP; CD46) that predispose to the development of aHUS were first identified in 2003. MCP is a membrane-bound complement regulator that acts as a cofactor for the factor I-mediated cleavage of C3b and C4b deposited on host cells. More than 20 different mutations in MCP have now been identified in patients with aHUS. Many of these mutants have been functionally characterized and have helped to define the pathogenic mechanisms leading to aHUS development. Over 75% of the reported mutations cause a reduction in MCP expression, due to homozygous, compound heterozygous or heterozygous mutations. This deficiency of MCP leads to inadequate control of complement activation on endothelial cells after an initiating injury. The remaining MCP mutants are expressed, but demonstrate reduced ligand (C3b/C4b) binding capacity and cofactor activity of MCP. MCP mutations in aHUS demonstrate incomplete penetrance, indicating that additional genetic and environmental factors are required to manifest disease. MCP mutants as a cause of aHUS have a favorable clinical outcome in comparison to patients with factor H (CFH) or factor I (IF) mutations. In 90% of the renal transplants performed in patients with MCP-HUS, there has been no recurrence of the primary disease, whilst >50% of factor I or factor H deficient patients have had a prompt recurrence. This highlights the importance of defining and characterizing the underlying genetic defects in patients with aHUS.     

Characterization of three monoclonal antibodies to membrane co-factor protein (MCP) of the complement system and quantification of MCP by radioassay.

MCP is a widely distributed regulatory glycoprotein of the complement system which binds C3b and C4b and has factor I-dependent co-factor activity. Monoclonal antibodies raised to lymphocytes (E4.3), chorionic microvilli (GB24) and an embryonal carcinoma cell line (TRA-2-10) recognize MCP (CD46). GB24 inhibited both the binding of MCP to its ligand iC3 and co-factor activity; E4.3 and TRA-2-10 did not. The binding of GB24 to cells bearing MCP was not cross-inhibited by E4.3 or TRA-2.10, but TRA-2-10 blocked binding and displaced pre-bound E4.3. Using these antibodies, we developed a radioassay for quantifying the number of MCP molecules/cells. Human peripheral blood mononuclear (PBMC) and polymorphonuclear cells (PMN) had about 10,000 MCP cell; platelets had about 600/cell, and no MCP was found on erythrocytes. Neoplastic hematopoietic cell lines, of myelocytic and T lymphocytic origin, had several-fold more (20-60,000) molecules cell than peripheral blood cells or B cell lines (about 12,000). Malignant epithelial cell lines. HeLa (about 100,000/cell) and HEp-2 (about 250,000 cell) had the highest MCP expression of any cells examined. These monoclonal antibodies--especially GB24, which blocks MCP function--and the direct binding assay will facilitate the further analysis of the biology of this complement regulatory protein.     

Monoclonal antibodies to the human multicatalytic proteinase (proteasome).

Multicatalytic proteinase is an intracellular enzyme composed of at least 12 different subunits. Seven murine hybridoma cell lines secreting antibodies to human multicatalytic proteinase (MCP) were established. The antibodies reacted with 4 different subunits of the oligomeric protein. Three of the antibodies bound to identical or closely spaced epitopes on the largest subunit, as shown by binding competition. Some of the antibodies cross-reacted with MCP from rat or rabbit, but none with lobster MCP. Glycoprotein components could not be detected in human MCP. The monoclonal antibodies and two polyclonal rabbit antibodies did not specifically inhibit the enzymatic activity of human MCP. Electrophoretic analysis of MCP immunoprecipitated from human placenta, liver, kidney, or HeLa cell extracts with antibodies to 3 different subunits suggested that the subunit compositions are very similar or identical.     

Immunohistochemical demonstration of membrane cofactor protein (MCP) of complement in normal and diseased kidney tissues.

The immunohistochemically stained membrane cofactor protein of complement (MCP/CD46), one of the complement regulatory proteins, was up-regulated in some diseased kidney tissues. MCP in diseased kidneys was strongly concentrated along the glomerular capillary walls as well as in the mesangial regions, while MCP in normal kidneys was weakly detected in all glomerular structural cells and in the epithelial cells of tubules. Since the enhanced staining was noted in those areas where depositions of C3b/C3c occurred, ongoing complement reaction might be responsible for the up-regulation of MCP expression. MCP expression may be up-regulated by complement fragments generated during complement activation in glomerulonephritis. Furthermore, anti-MCP staining was stronger in intensity in patients with moderate to massive proteinuria, indicating that up-regulation of MCP expression could be directly correlated to the kidney damage.     

流体切应力下血管内皮单核细胞趋化蛋白-1的表达

目的研究流体切应力对人血管内皮细胞的单核细胞趋化蛋白-1(MCP-1)表达的影响,探讨血流动力在动脉粥样硬化(AS)发生早期中的作用.方法利用平行板流动腔对血管内皮细胞施加不同切应力,分别采用夹心酶联免疫吸附测定(EL,ISA)及逆转录-聚合酶链反应(RT-PCR)法检测MCP-1蛋白及mRNA水平.结果以0.72Pa切应力进行不同时间作用,0.5h后MCP-1mRNA即达到静态时(0.160±0.037)的4倍(0.684±0.033),5h时略有升高,达0.707±0.089,12h后下降到低于对照组的水平(0.036±0.006,P＜0.001).灌流液中MCP-1蛋白时间依赖性增加,但5h后增长趋缓;而在不同切应力(0.30、0.72、2.40Pa)相同时间(5h)下,0.72Pa的作用最显著,MCP-1蛋白比静态对照增加了2倍多,mRNA水平则升高达4倍.结论MCP-1的表达对切应力的变化反应强烈,持续稳定的切应力则下调MCP-1的表达,此研究结果表明血流紊乱可促进AS病变的发生发展.     

Complement regulatory proteins in early human fetal life: CD59, membrane co-factor protein (MCP) and decay-accelerating factor (DAF) are differentially expressed in the developing liver.

The human fetus appears to be capable of protecting itself from maternal complement (C) from an early stage in development by expressing the C regulatory proteins decay-accelerating factor (DAF), membrane co-factor protein (MCP) and CD59 on fetally derived trophoblast at the feto-maternal interface. In this study we have examined the ontogeny of these proteins within the fetus itself and have focused on the liver which represents a major site of haemopoiesis during development. Immunostaining revealed that DAF, MCP and CD59 are all expressed from at least 6 weeks of gestation in the liver but that these proteins display distinct distribution patterns. CD59 was broadly distributed both within the epithelial and haemopoietic compartments, but expression of C3 convertase regulators was more restricted. DAF expression was limited to isolated cells within haemopoietic nests and the epithelium was DAF-negative. Although MCP expression on haemopoietic cells was also limited, by contrast with DAF the developing hepatic epithelium was strongly MCP-positive. Typical CD59 and MCP components were observed in fetal liver extracts by immunoblotting, although liver MCP components consistently migrated 4000-5000 MW ahead of those observed on placental trophoblast. Differences in the distribution of these proteins were also observed between the fetal and adult liver. In particular, by comparison with fetal hepatic epithelium, there was an apparent loss of MCP expression from adult hepatocytes. Thus, MCP appears to be developmentally regulated in the human liver and is expressed in the absence of DAF on the early hepatic epithelium. Overall, this study suggests that C regulatory proteins, and in particular CD59 and MCP, are required from the very early stages of gestation within the fetus itself.     

Distribution of membrane cofactor protein of complement on human peripheral blood cells. An altered form is found on granulocytes

Membrane cofactor protein (MCP) of human complement is an iC3/C3b-binding glycoprotein with a characteristic two-band (63 kDa and 55 kDa) pattern on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Using affinity chromatography, it has been found on human mononuclear cells and platelets. MCP has been purified and shown to be a cofactor for the I-mediated cleavage of C3b. A rabbit polyclonal antibody was produced to the purified protein and this reagent employed to analyze the distribution of MCP on human peripheral blood cells. Flow cytometric analysis indicated that MCP is unimodally present on all platelets, granulocytes, T helper lymphocytes, T suppressor/cytotoxic lymphocytes, B lymphocytes, natural killer cells and monocytes but not erythrocytes. The presence of MCP on granulocytes was unexpected. To evaluate this, MCP was isolated by immunoprecipitation and analyzed by SDS-PAGE followed by autoradiography. The Mr of granulocyte MCP was that of a single broad band in which the typical two-band pattern could not be distinguished. Alterations in the conditions of the affinity column procedure increased the efficiency of the isolation of monocyte MCP and led to the reproducible isolation of granulocyte MCP. These results indicate that MCP of granulocytes has both structural and functional differences compared to MCP of plateletes and mononuclear cells. The wide distribution of MCP among peripheral blood cells supports the concept that MCP is important in the protection of host cells from complement-mediated damage.     

反义单核细胞趋化蛋白—1转基因表达对单核细胞在动脉内膜粘 …

目的 了解动脉粥样便２化发病过程中单核细胞粘附并进入动脉内膜的机制,分析单核细胞趋化蛋白－１（ＭＣＰ－１）基因表达对单核细胞粘附动脉内膜的作用。方法 以实验性高脂主轻度氧化ＬＤＬ（ＭＭ－ＬＤＬ）局部保留灌注的家兔股动脉 为模型,采用ＤＯＴＡＰ阳离子脂质体包裹ＬＮＣＯ－ａｎｔｉＭＣＰ－１质粒,将反义ＭＣＰ－１ ＣＤＮＡ定位导入家兔股动脉鞘及周围组织,以原位杂交、Ｎｏｒｔｈｅｒｎ杂交及狭缝杂交法反义Ｍ     

Chemokine-mediated inflammation: Identification of a possible regulatory role for CCR2

The chemokine receptor CCR2 binds four pro-inflammatory monocyte chemoattractant proteins, designated MCP1/CCL2, MCP2/CCL8, MCP3/CCL7 and MCP4/CCL13. This study demonstrates the important biology of this receptor during the response to the chemokine milieu. Competitive chemotaxis and calcium flux assays were performed utilising mixtures of chemokines to assess a hierarchal arrangement of chemokine prepotency; these demonstrated that the MCP2-CCR2 interaction is able to supersede signals generated by RANTES, another pro-inflammatory chemokine, or the homeostatic chemokine SDF1. These observations were validated using three physiologically relevant monocytic cell lines. Having identified the importance of CCR2, experiments were then performed to examine the signal transduction processes coupled to this receptor. G protein coupling was initially examined; Cholera toxin reduced the chemotactic response to MCP2 (p<0.001), whilst the response to the other MCP chemokines remained normal. The response to MCP2 was uniquely inhibited by elevated concentrations of cAMP and, unlike MCP1, 3 and 4 (p<0.05), MCP2 failed to inhibit adenylate cyclase. Expression of dominant negative H-ras demonstrated that each MCP chemokine required active ras in order to elicit ERK activation and a chemotactic response. Unlike MCP1, MCP2 failed to induce nuclear translocation of activated ERK1 or subsequent induction of c-Myc expression. Akt activation also showed ligand-specific differences, with MCP2 producing a delayed response compared to the other MCP chemokines. Together these data highlight the importance of CCR2 and suggest that it is a powerful tool for fine tuning the immune response.