Peripheral Connective Tissue Research Articles

Analysis of the relationship of refractory gout between potential biomarkers and diet structure and lifestyle based on 1H-NMR.

We investigated the different life styles among the diet structures and exercise patterns of 100 patients with refractory gout and 79 healthy volunteers; of these, we selected 39 patients and 20 healthy volunteers for serum proton magnetic resonance (1H-NMR) metabolic network detection. We determined the potential biomarkers of refractory gout and attempted to explore the relation between potential biomarkers and diet structures and exercise patterns. The study employed a questionnaire survey to analyze diet structures and exercise patterns from 100 patients of refractory gout and 79 healthy volunteers. At the same time, using 1H-NMR metabolic technology to analyze the metabolites present in the serum samples obtained from 39 patients of refractory gout (group B) and 20 healthy subjects (group A). Employing MestReNova (Version 8.0.1) to analyze the metabolitesmaps, collecting the NMR results, further importing into SIMCA-P+ 14.0 software (Umetrics, Sweden) for principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), and orthogonal partial least squares discriminant analysis (OPLS-DA) statistical analysis. Combining patterns recognition and multivariate statistics, potential biomarkers were searched. Other experimental data, including creatinine and adiponectin, were counted by the SPSS21.0. The measurement data were expressed by X ± S and t test. The counting data were expressed in percent and performed by X2 test. Our results revealed that patients with gout tended to be obese, and there were differences in their lifestyle with exercise, sleep, and smoking, as well as in their preference for fructose drinks, alcohol, and total and structural distribution of meat, milk, eggs, and so on when compared with the healthy volunteers. Importantly, we found the adiponectin in the gout group was lower as compared to the healthy group. Further, metabolomics in combination with KEGG analysis revealed that the biosynthesis of aminoacyl tRNA, biosynthesis of valine, leucine, and isoleucine, metabolism of alanine, aspartic, and glutamate, metabolism of glycine, serine, and threonine, phenylalanine, glycolysis/gluconeogenesis, ketone body synthesis and degradation, metabolism of D-glutamine, citric acid cycle (TCA cycle), triglyceride metabolism, and others could be used as specific biomarkers of this disease. Recurrent refractory gout and formation of tophus may be related to the diet structures and lifestyles between the patients and the healthy people, and their abnormal metabolic network may be related to the disorder of mitochondrial energy metabolism, which further results in abnormal metabolism of glucose, lipids, amino acids, and deposition of uric acid in joints, peripheral connective tissue, and kidney, inducing an inflammatory response.

Spatial gene expression in the adult rat patellar tendon

Tendons are dense connective tissues with relatively few cells which makes studying the molecular profile of the tissue challenging. There is not a consensus on the spatial location of various cell types within a tendon, nor the accompanying transcriptional profile. In the present study, we used two male rat patellar tendon samples for sequencing-based spatial transcriptomics to determine the gene expression profile. We integrated our data with a mouse Achilles single cell dataset to predict the cell type composition of the patellar tendon as a function of location within the tissue. The spatial location of the predicated cell types suggested that there were two populations of tendon fibroblasts, one located in the tendon midsubstance, while the other localized with red blood cells, pericytes, and immune cells to the tendon peripheral connective tissue. Of the highest expressed spatially variable genes, there were multiple genes with known function in tendon: Col1a1, Col1a2, Dcn, Fmod, Sparc, and Comp. Further, a novel spatially regulated gene (AABR07000398.1) with no known function was identified. The spatial gene expression of tendon associated genes (Scx, Thbs4, Tnmd, Can, Bgn, Lum, Adamts2, Lox, Ppib, Col2a1, Col3a1, Col6a2) was also visualized. Both patellar tendon samples had similar expression patterns for all these genes. This dataset provides new spatial insights into gene expression in a healthy tendon.

Periodontal ligaments enhance neurite outgrowth in trigeminal ganglion neurons through Wnt5a production induced by mechanical stimulation.

The peripheral sensory nerve must be maintained to perceive environmental changes. Daily physiological mechanical stimulations, like gravity, floor reaction force, and occlusal force, influence the nerve homeostasis directly or indirectly. Although the direct axonal membrane stretch enhances axon outgrowth via mechanosensitive channel activation, the indirect mechanisms remain to be elucidated. In this study, we identified the indirect pathways where Wnt5a was a molecular cue released by mechanically stimulated rat periodontal ligament (rPDL) cells. qRT-PCR and ELISA showed that mechanically stimulated rPDL cells enhanced Wnt5a expression level and Wnt5a protein in a Ca2+-dependent manner. The inhibitors of PI3K (LY294002) and MEK1/2 (U0126) suppressed the Akt/PKB and ERK1/2 phosphorylation, respectively, in Western blotting analysis and consequently abolished the increase in Wnt5a expression. Similarly, PF573228, a focal adhesion kinase inhibitor, attenuated Akt- and ERK1/2-phosphorylation and Wnt5a expression. Importantly, the culture medium of stretched PDL cells enhanced neurite elongation, sprouting, and branching in trigeminal ganglion neurons that project to PDL. Moreover, treatment with an anti-Wnt5a antibody (to neutralize Wnt5a activity), AP7677a (anti-Ryk antibody, to block Ryk receptor activity), or strictinin (Ror1 inhibitor) suppressed the morphological changes. These findings reveal the indirect mechanisms that Wnt5a, released from the connective tissues in response to mechanical stimulation, enhances the outgrowth of the peripheral nerves. Our study suggests that the peripheral connective tissues regulate peripheral nerve homeostasis and that Wnt5a signaling could be targeted for the treatment of peripheral nerve disorders.

Functional loss of ubiquitin-specific protease 14 may lead to a novel distal arthrogryposis phenotype.

Multiple congenital contractures (MCC) comprise a number of rare, non-progressive conditions displaying marked phenotypic and etiologic heterogeneity. A genetic cause can be established in approximately half of the affected individuals, attributed to genetic defects in the formation and functioning of the central and peripheral nervous system, neuromuscular junctions, skeletal muscles, and connective tissue. Ubiquitin-specific protease 14 (USP14) encodes a major proteasome-associated deubiquitinating enzyme with an established dual role as an inhibitor and an activator of proteolysis, maintaining protein homeostasis. Usp14-deficient mice show a phenotype similar to lethal human MCC phenotypes, with callosal anomalies, muscle wasting, and early lethality, attributed to neuromuscular junction defects due to decreased monomeric ubiquitin pool. We describe a new, autosomal recessive MCC phenotype in three fetuses from two different branches of a consanguineous family, presenting with distal arthrogryposis, underdevelopment of the corpus callosum, and dysmorphic facial features. Exome sequencing identified a biallelic 4-bp deletion (c.233_236delTTCC; p.Leu78Glnfs*11, SCV002028347) in USP14, and sequencing of family members showed segregation with the phenotype. RT-qPCR experiment in an unaffected heterozygote revealed that mutant USP14 was expressed, indicating that abnormal transcript escapes nonsense-mediated mRNA decay. We propose that herein described fetuses represent the first human phenotype of USP14 loss, with callosal anomalies and/or cortical malformations, multiple contractures, and recognizable dysmorphic facial features.

Histological examination of the effects of epidermal growth factor on regeneration of acute peripheral nerve injuries on rabbit model.

Peripheral nerve injuries are one of the most common and costly injuries especially in the young population. In this study, it is aimed to determine the histological role of epidermal growth factor (EGF) in nerve regeneration with an acute damage made on sciatic nerve in the rabbit model. We used 18 New Zealand rabbits (nine in control group and nine in experimental group). Each group was divided into two groups consisting of five rabbits planned for diameter measurement and four rabbits planned for spatial measurement. The sciatic nerve exploration in the right flank of each animal, full-thickness nerve damage, and then epineural repair was made by a single researcher. 10 µg/kg EGF was given to the repair area of the experimental group and five more EGF injections were given to the experimental group every other day postoperatively. In the control group, we used saline solution. Rabbits were observed for 8 weeks. During follow-up, two rabbits died. At the end of 8 weeks, the nerve tissue of each animal was evaluated histologically and morphologically. In the experimental group consisting of five rabbits, the mean thickness of connective tissue (epineurium+ mesoneurium) was 156,867 µm; while, in the control group, the thickness was 25,170 µm. In the other groups, the numerical increase in epineurium and mesoneurium areas was detected in the EGF (+) group as a result of the comparative spatial measurements. Epineurium and mesoneurium enlargement was observed in the EGF-given group. Adipocyte and capillary increase was observed in connective tissue. EGF increases epineurium and mesoneurium diameters in peripheral connective tissue in acute peripheral nerve injury regeneration. However, further studies are needed to understand this effect clinically and physiologically.

Insights into the mechanism of vascular endothelial cells on bone biology.

In the skeletal system, blood vessels not only function as a conduit system for transporting gases, nutrients, metabolic waste, or cells but also provide multifunctional signal molecules regulating bone development, regeneration, and remodeling. Endothelial cells (ECs) in bone tissues, unlike in other organ tissues, are in direct contact with the pericytes of blood vessels, resulting in a closer connection with peripheral connective tissues. Close-contact ECs contribute to osteogenesis and osteoclastogenesis by secreting various cytokines in the paracrine or juxtacrine pathways. An increasing number of studies have revealed that extracellular vesicles (EVs) derived from ECs can directly regulate maturation process of osteoblasts and osteoclasts. The different pathways focus on targets at different distances, forming the basis of the intimate spatial and temporal link between bone tissue and blood vessels. Here, we provide a systematic review to elaborate on the function of ECs in bone biology and its underlying mechanisms based on three aspects: paracrine, EVs, and juxtacrine. This review proposes the possibility of a therapeutic strategy targeting blood vessels, as an adjuvant treatment for bone disorders.

Insights into mast cell hyperplasia in aspirin-exacerbated respiratory disease from transcriptional profiling of polyp mast cells

Asthma is a complex, heterogeneous lung disease arising from the interaction of genetic, environmental, and immunologic factors. An emerging feature of asthma across multiple disease endotypes is the expansion of mast cells (MCs), tissue-resident granulocytes that are believed to participate in disease progression, in the airway smooth muscle, bronchial epithelium, and alveolar parenchyma.1 Of note, 2 main subsets of human MCs have been described, both of which expand during asthma: MCTC that contain the proteases tryptase and chymase and mainly reside in peripheral connective tissues and MCT that contain tryptase in the absence of chymase and reside within the epithelium.

The relationship between systemic sclerosis and hypertension and ecocardiographıc findings

Aims: The aim of this study was to evaluate the basic demographic and clinical features of systemic sclerosis in our patient group and to determine the relationship between the duration of disease and the development of hypertension in scleroderma patients. Settings and Design: Systemic sclerosis is a rare, autoimmune disease with a limited or widespread involvement of connective tissue of different organs. In the literature, it is recommended that each center following the scleroderma population remove their patient data. Methods and Material: Patients who were followed up with the diagnosis of systemic sclerosis were included in our study. The duration of the disease, the accompanying diseases, basic demographic characteristics, inflammation markers and echocardiographic characteristics of the patients were evaluated. A total of 150 patients were included in the study (87.3% female, mean age 47.7). The duration of the disease was 5.41 years. Results: 37% of the patients had hypertension. There was a positive correlation between disease duration and hypertension (r: 0.278, p: 0.001). Echocardiographic evaluation revealed pulmonary hypertension in 10 patients. Hypertension was more prevalent in this disease group than the population with the same characteristics. As the disease duration increased, the incidence of systemic hypertension increased. Conclusions: The first of the striking findings in our study was that the rate of pulmonary hypertension due to scleroderma was found to be similar to that in other Middle Eastern societies. In the second important finding, peripheral connective tissue involvement of scleroderma was found to be important in the development of systemic hypertension.

低浓度胰蛋白酶原代培养大鼠血管内皮细胞实验方法研究

目的：探索改进一种简单、经济和高纯度的大鼠血管内皮细胞分离培养方法。方法：采用2%戊巴比妥钠麻醉Wistar大鼠，在无菌条件下截取主动脉约3~4 cm，再将主动脉血管外翻使内膜暴露，用丝线结扎动脉两端，以0.125%胰蛋白酶消化18~20 min，在倒置相差显微镜下直接观察细胞生长和细胞形态特征，分别应用免疫组化和免疫荧光方法检测第VIII因子相关抗原抗体结合情况，对培养传代的血管内皮细胞进行鉴定。结果：采用0.125%胰蛋白酶直接消化可获得高纯度的大鼠主动脉血管内皮细胞。经过3~4天培养，细胞呈集落样散在分布于六孔培养板底，到10~12天时，细胞贴壁增长至覆盖大部分培养板底，约85%的细胞汇合成单层，呈现典型的“鹅卵石”样内皮细胞特征；此外，免疫组化和免疫荧光方法检测第VIII因子相关抗原抗体结合情况，发现大多数细胞胞浆呈现棕黄色和绿色荧光的阳性反应，显示分离培养的细胞主要是血管内皮细胞。结论：本改良的细胞培养方法操作简便，只需浓度低至0.125%胰蛋白酶即可获取较高纯度的血管内皮细胞，不需要较昂贵的胶原酶及内皮细胞生长因子，与现有的其他培养方法相比更为经济实用。 Objective: To explore a simple, economic and highly purified modified method to isolate and cul-ture the endothelial cells of rat thoracic aorta. Methods: Under an aseptic condition, the thoracic aorta was harvested in a male adult Wistar rat anesthetized with 2% pentobarbital sodium. After having removed the peripheral connective tissue and fat, the thoracic aorta was turned inside out to expose its intima. Then, the thoracic aorta ends were ligated with the sterile silk thread, and thoracic aorta intima was digested with 0.125% trypsin for 18 min - 20 min in centrifugal tube. Cell growth and cell morphology was directly observed under inverted phase contrast microscope; immunohistochemistry and immunofluorescence method is applied to detect and identify if the primary culture rat aortic endothelia cells (RAECs) are the vascular endothelial cells by their combining reactivity with VIII factor related antigen antibody. Results: After 3 - 4 days, the cultured rat aortic endothelial cells were distributed on the basement of six-well plates in a cluster. 10 - 12 days later, the adherent cells spread to cover most bottom of culture plate with about 85% of the adherent cells in a confluent monolayer, and show a typical cobblestone appearance which is the characteristic of the vascular endothelial cells. In addition, immunohistochemical staining and mmunofluorescence staining with monoclonal anti-Factor-VIII antigen antibody in culturing RAECs were shown by the tan and green fluorescence positive reactive particulate matter found in most of the cell cytoplasm, suggesting that the primary culture RAECs are the vascular endothelial cells. Conclusions: Just using the concentrations as low as 0.125% trypsin, our modified cultural method of vascular endothelial cells is a convenient, economical and applicable one with a higher cell activity and purity, no needing the expensive collagen enzyme and endothelial cell growth factor.

Unilateral perivertebral fibrosis associated with lordosis, kyphosis and scoliosis (LKS) in farmed Chinook salmon in New Zealand.

Vertebral column lordosis, kyphosis and scoliosis (LKS) can result in downgrading of farmed Chinook salmon Oncorhynchus tshawytscha in New Zealand. No cause of LKS has been identified. Radiography and histology were used to quantify LKS and perivertebral fibrosis in 27 fish with LKS visible at harvest and 30 visually normal fish from 3 New Zealand farms. Radiographic LKS was present in all 27 fish with LKS and in 18 of 30 fish without visible LKS. Quantification of the radiographic severity revealed significantly higher radiographic severity scores in fish with visible LKS (mean ± SD = 5.89 ± 2.41) than in fish with no visible, but radiographic LKS (1.44 ± 0.86, p < 0.001). The most frequent histological finding was unilateral perivertebral fibrosis that often extended into the horizontal septum and adjacent myomeres resulting in separation or loss of myocytes. Fibrosis was visible in all fish with LKS and in 12 of 30 fish without visible LKS. Fibrosis scores were higher in fish with visible LKS (3.32 ± 1.71) than in fish without visible LKS (0.35 ± 0.57, p < 0.001). The radiographic LKS severity scores were significantly correlated to the fibrosis scores (R2 = 0.59 p < 0.001) in the fish. Histology of other tissues revealed multifocal inflammation within muscle, peripheral connective tissues and myocardium which were considered most likely incidental in these fish. In this study, LKS was consistently and significantly associated with perivertebral fibrosis, suggesting that perivertebral fibrosis is an important process in the development of LKS. Further research to determine the cause of the fibrosis is required.

Transcriptional profiling of constitutive mast cells reveals a unique gene expression signature and highlights their heterogeneity across tissues (HYP4P.303)

Abstract Constitutive mast cells (MC) are long-lived sentinel cells residing in peripheral connective tissue near the microvasculature and nerve endings. Similar to basophils (Ba), MC express the high-affinity IgE receptor FcεR1α, and are frequently implicated in the pathobiology of allergic diseases. Although protease expression in murine MC varies between tissues, the full extent of their diversity across compartments is not known, and the study of MCs is hindered by their rarity and location. In collaboration with the Immunological Genome Project, we developed techniques for isolating MC from a wide variety of murine tissues for microarray analysis. Hierarchical clustering and principal component analysis of MC versus Ba and other immune cells indicate that Ba are transcriptionally more similar to other circulating granulocytes (eosinophils, and neutrophils) than to MC. Furthermore, granulocytes and other tissue resident myeloid cells (macrophages and dendritic cells) are closer to each other and to lymphoid cells than either group is to constitutive MC. Further analysis revealed a core MC transcriptional signature not seen in other immune cell populations, but MC heterogeneity across tissue compartments was similar to that seen with dendritic cells, indicating that their diversity goes far beyond protease expression. Our results provide novel insights into this unique cell type and lay the groundwork for future studies on the activation and function of MC in peripheral tissue.

Metallothionein from Pseudosciaena crocea: expression and response to cadmium-induced injury in the testes.

Metallothioneins (MTs) are a family of stress proteins that are involved in the process of detoxification and anti-oxidation. Previous studies have focused mostly on the expression and functions of MTs in the non-reproductive tissues of aquatic vertebrates. However, there have been only a few reports regarding the functions of MTs in the reproductive tissues of such vertebrates. In order to investigate the function of MTs during spermatogenesis in Pseudosciaena crocea, reverse-transcription polymerase chain reaction (PCR) and rapid amplification of cDNA ends were performed to obtain the P. crocea MT complete cDNA sequence from the total RNA of the testes for the first time. MT was detected in the liver, kidneys, testes, spleen, gill and muscle of P. crocea by tissue-specific expression analysis. Meanwhile, immunohistochemistry staining indicated that the MT protein was localized in germ cells, Sertoli cells and the peripheral connective tissues in P. crocea testes. Furthermore, acute toxicity tests were conducted with cadmium (Cd) to determine the 96h-medial lethal concentration value. The toxic effects of Cd on the microstructure and ultrastructure of the testes were observed. In addition, the changes in MT mRNA expression levels in the testes after Cd exposure were measured using real-time quantitative PCR. Consequently, we suggest that MTs play an important role in spermatogenesis and testes protection against Cd toxicity in P. crocea.

Glycoconjugate expression in the extracellular matrix of the mouse lung (87.7)

Introduction: Glycoconjugates have been implicated in various lung extracellular structures such as the galactose‐binding elastin receptor complex; however, little is known about expression of carbohydrate moieties in lung extracellular matrix (ECM). Methods: To investigate structural implications of glycoconjugate expression in the ECM, we used a panel of 33 biotinylated lectins to label decellularized mouse lungs harvested from 8‐11 week C57/B6 mice. Lungs were decellularized by serial washes through the trachea and pulmonary artery. Standard OCT thin section analysis as well as precision‐cut lung slice (200‐300μm) histology were performed. Lung samples were labeled with lectins (20μg/mL), secondarily labeled with a streptavidin‐fluorescein conjugate and analyzed by fluorescence confocal microscopy. Results: Decellularized mouse lungs showed a lectin‐binding pattern consistent with differential staining of the axial and peripheral connective tissue elements. Some lectins (N=10) demonstrated weak signal interpreted as negative. Others (N=17) stained pleural and subpleural zones suggesting selective staining of the peripheral connective tissue system. Another group (N=7) prominently stained the acinar septae suggesting selective staining of the axial connective tissue system. All lectin labeling was demonstrated at wavelengths that preclude elastin autofluorescence. Conclusions: The differential labeling pattern of the ECM with lectins suggests their utility as monospecific probes of both peripheral and axial connective tissue systems in the decellularized mouse lung.Grant Funding Source: Supported by NIH grant 04925

Clinical Phenotypes and ABCC6 Gene Mutations in Brazilian Families with Pseudoxanthoma Elasticum

Pseudoxanthoma elasticum (PXE; OMIM 264800) manifests with characteristic skin lesions of yellowish papules which coalesce into plaques of inelastic and leathery skin on the predilection sites (1). The ocular findings consist of angioid streaks, choroidal neovascularization and subretinal hemorrhages resulting in loss of visual acuity and occasional blindness. Cardiovascular problems include hypertension, intermittent claudication, and occasional myocardial infarcts and stroke. The prevalence of PXE is estimated to be in the range of 1:50,000–70,000 and to be more frequent in females than in males. The diagnosis can be challenging to clinicians due to late-onset of clinical manifestations and considerable heterogeneity. PXE is associated with mutations in the ABCC6 gene which encodes a transmembrane efflux transporter expressed primarily in the liver and the kidneys (2). Consequently, PXE has been suggested to be a metabolic disorder with ectopic mineralization of the peripheral connective tissues. Recent studies have also suggested that cutaneous features of PXE can be found in patients with generalized arterial calcification of infancy due to mutations in the ENPP1 gene (3, 4). Previous studies, which have documented close to 600 distinct mutations in the ABCC6 gene, have suggested the presence of unique mutations affecting certain ethnic groups with different ancestral backgrounds (5, 6). In this study, we asked the specific question whether Brazilian patients of mixed European, Native Indian and African ancestry with PXE harbor unique ABCC6 mutations, and whether such mutations might be correlated with the clinical phenotypes in this population with particular reference to heterozygous carriers.

Implantation of Allogenic Synovial Stem Cells Promotes Meniscal Regeneration in a Rabbit Meniscal Defect Model

Indications for surgical meniscal repair are limited, and failure rates remain high. Thus, new ways to augment repair and stimulate meniscal regeneration are needed. Mesenchymal stem cells are multipotent cells present in mature individuals and accessible from peripheral connective tissue sites, including synovium. The purpose of this study was to quantitatively evaluate the effect of implantation of synovial tissue-derived mesenchymal stem cells on meniscal regeneration in a rabbit model of partial meniscectomy. Synovial mesenchymal stem cells were harvested from the knee of one New Zealand White rabbit, expanded in culture, and labeled with a fluorescent marker. A reproducible 1.5-mm cylindrical defect was created in the avascular portion of the anterior horn of the medial meniscus bilaterally in fifteen additional rabbits. Allogenic synovial mesenchymal stem cells suspended in phosphate-buffered saline solution were implanted into the right knees, and phosphate-buffered saline solution alone was placed in the left knees. Meniscal regeneration was evaluated histologically at four, twelve, and twenty-four weeks for (1) quantity and (2) quality (with use of an established three-component scoring system). A similar procedure was performed in four additional rabbits with use of green fluorescent protein-positive synovial mesenchymal stem cells for the purpose of tracking progeny following implantation. The quantity of regenerated tissue in the group that had implantation of synovial mesenchymal stem cells was greater at all end points, reaching significance at four and twelve weeks (p < 0.05). Tissue quality scores were also superior in knees treated with mesenchymal stem cells compared with controls at all end points, achieving significance at twelve and twenty-four weeks (3.8 versus 2.8 at four weeks [p = 0.29], 5.7 versus 1.7 at twelve weeks [p = 0.008], and 6.0 versus 3.9 at twenty-four weeks [p = 0.021]). Implanted cells adhered to meniscal defects and were observed in the regenerated tissue, where they differentiated into type-I and II collagen-expressing cells, at up to twenty-four weeks. Synovial mesenchymal stem cells adhere to sites of meniscal injury, differentiate into cells resembling meniscal fibrochondrocytes, and enhance both quality and quantity of meniscal regeneration.

Administration of vitamin K does not counteract the ectopic mineralization of connective tissues in Abcc6-/- mice, a model for pseudoxanthoma elasticum

Pseudoxanthoma elasticum (PXE) is a heritable multisystem disorder manifesting with ectopic calcification of peripheral connective tissues, caused by mutations in the ABCC6 gene. Alterations in vitamin K metabolism have been suggested to contribute to the pathomechanisms of the mineralization process. In this study we administered vitamin K or its glutathione conjugate (K3-GSH) into Abcc6-/- mice which recapitulate features of PXE. Oral administration of vitamin K2 in dosages, which vastly exceed the amounts in control diet or the recommended amounts for humans, did not alter the ectopic mineralization in Abcc6-/- mice. Similarly, intravenous administration of K3-GSH did not alter the degree of mineralization. Testing of vitamin K2, K3 and K3-GSH in an in vitro calcification system provided no evidence of mineralization inhibition. Collectively, our data suggest that vitamin K deficiency in the peripheral tissues is not a simple explanation for development of mineral deposits in PXE.

Mastocytosis: oral implications of a rare disease

Mastocytosis encompasses a group of rare clinical entities, which are characterized by an abnormal growth and, usually, low accumulation of clonal and morphologically abnormal mast cells (MCs), within one or more organs. Clinical presentations are quite variable and symptoms are usually related to the release of mast cell mediators, tissue infiltration by MC (usually in the aggressive categories of the disease), or both. Mast cells are hematopoietic-derived cells that reach phenotypic maturity in the mucosa and peripheral connective tissues. These cells play an active role both on immunologic and non-immunologic processes. Within the oral cavity, MCs reside in the connective tissues, in physiologic conditions, and their number is elevated in pathologic situations resulting from immunoinflammatory processes, such as pulpal inflammation and periodontal disease. As MCs influence so many phenomena within the oral cavity, mastocytosis may manifest itself in the oral tissues. Patients with mastocytosis should be put under special care by dental professionals, in what concerns not only general patient management, but also drug prescription, as they are particularly prone to anaphylaxis and other peri and post-operative complications. Several allergens or mast cell activation triggers such as local anesthetics, zinc oxide, eugenol, penicilins, metals and oral hygiene products are frequently administered or prescribed by dentists. Patients with mastocytosis may also require stress management, during dental consultation. This review aims to briefly summarize the potential ways in which mast cell disease may affect the oral cavity and the dental management of mastocytosis affected patients.

Pseudoxanthoma Elasticum: Molecular Genetics and Putative Pathomechanisms

Pseudoxanthoma elasticum (PXE), a prototypic heritable disorder with ectopic mineralization, manifests with characteristic skin findings, ocular involvement and cardiovascular problems, with considerable morbidity and mortality. The classic forms of PXE are due to loss-of-function mutations in the ABCC6 gene, which encodes ABCC6, a transmembrane efflux transporter expressed primarily in the liver. Several lines of evidence suggest that PXE is a primary metabolic disorder, which in the absence of ABCC6 transporter activity, displays reduced plasma anti-mineralization capacity due to reduced fetuin-A and matrix gla-protein (MGP) levels. MGP requires to be activated by gamma-glutamyl carboxylation, a vitamin K-dependent reaction, to serve in an anti-mineralization role in the peripheral connective tissue cells. Although the molecules transported from the hepatocytes to circulation by ABCC6 in vivo remain unidentified, it has been hypothesized that a critical vitamin K derivative, such as reduced vitamin K conjugated with glutathione, is secreted to circulation physiologically, but not in the absence of ABCC6 transporter activity. As a result, activation of MGP by gamma-glutamyl carboxylase is diminished, allowing slow yet progressive mineralization of connective tissues characteristic of PXE. Understanding of the pathomechanistic details of PXE provides a basis for the development of targeted molecular therapies for this currently intractable disease.

Study on the clinicopathological characteristics and pattern of lymph node metastasis in patients with gastric remnant cancer

To investigate clinicopathological characteristics and the pattern of lymph node metastasis of patients with gastric remnant cancer. The data of the clinicopathological characteristics and the pattern of lymph node metastasis in 56 patients with gastric remnant cancer treated from March 1994 to December 2008 was investigated and compared with those in 1171 patients with primary gastric cancer treated over the same period. Fifty-six patients (4.6%) with gastric remnant cancer were enrolled in this study during the period. Compared with patients with primary gastric cancer, the age of cancer onset was older [(64.3+/-9.0) vs. (58.3+/-12.6) yrs], lymph node metastasis rate was higher (31.8% vs. 25.5%), Borrmann's classification was later and neighbor organ resection rate was higher (57.1% vs. 26.4%) in patients with gastric remnant cancer; the differences were all significant (chi2=18.800, 11.679, 9.177, 25.190; P<0.05). Patients with gastric remnant cancer who underwent lymph node dissection tended to have a higher incidence of No.10 (splenic hilar lymph node) and No.11 (splenic artery lymph node) group lymph node metastasis than those in primary gastric cancer (chi2=5.558, 6.099; P<0.05). In contrast, patients with primary gastric cancer had a higher incidence of No. 2 (left cardiac lymph node), No.3 (lesser curvature lymph node) and No.8 (common hepatic artery lymph node) group lymph node metastasis than those in gastric remnant cancer (chi2=15.508, 6.003, 4.084; P<0.05). The jejunal mesentery lymph node metastasis was 24.0% (6/25) in patients with gastric remnant cancer and the peripheral connective tissue infiltration rate was 14.3% (8/56). It suggested that patients with gastric remnant cancer has different clinicopathologic characteristics and the pattern of lymph node metastasis from those with primary gastric cancer. D2 lymph node dissection of proximate gastric cancer and jejunal mesentery lymph node dissection should be the standard operation for these patients; but combined neighboring organ resection should be taken into consideration.

Histological basis of the liver hanging maneuver

Liver hanging maneuver (LHM) consists in passing a tape between the retrohepatic inferior vena cava (RHIVC) and the liver to perform various kinds of hepatectomies. LHM is a well-known procedure but its histological basis remains poorly documented. Ten anatomical specimens comprising RHIVC, and surrounding hepatic parenchyma were studied after conventional staining and immunohistochemistry with specific antibody for alpha smooth muscle actin. RHIVC wall structure consists of a thick muscular layer of longitudinal smooth muscle fibers and a peripheral loose connective tissue without smooth muscle fibers adherent to the liver parenchyma. This loose connective tissue between the liver and the RHIVC is the avascular plane for the passage of the clamp during LHM. The histological structure of the RHIVC does not seem to have any special hemostatic property. The low bleeding rate during LHM can be only explained by the very low density of RHIVC afferent veins.