bluuebunny/crossref_metadata_2025 huggingface dataset:
The association of mammographic density with ductal carcinoma in situof the breast: the Multiethnic Cohort
Authors: Gill Jasmeet K , Maskarinec Gertraud , Pagano Ian , Kolonel Laurence N
Published: June 2006

Introduction

It is well established that women with high mammographic density are at greater risk for breast cancer than are women with low breast density. However, little research has been done on mammographic density and ductal carcinoma in situ (DCIS) of the breast, which is thought to be a precursor lesion to some invasive breast cancers.

Method

We conducted a nested case-control study within the Multiethnic Cohort, and compared the mammographic densities of 482 patients with invasive breast cancer and 119 with breast DCIS cases versus those of 667 cancer-free control subjects. A reader blinded to disease status performed computer-assisted density assessment. For women with more than one mammogram, mean density values were computed. Polytomous logistic regression models were used to compute adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for two measurements of mammographic density: percentage density and dense area.

Results

Mammographic density was associated with invasive breast cancer and breast DCIS. For the highest category of percentage breast density (≥50%) as compared with the lowest (<10%), the OR was 3.58 (95% CI 2.26–5.66) for invasive breast cancer and 2.86 (1.38–5.94) for breast DCIS. Similarly, for the highest category of dense area (≥45 cm2) as compared with the lowest (<15 cm2), the OR was 2.92 (95% CI 2.01–4.25) for invasive breast cancer and 2.59 (1.39–4.82) for breast DCIS. Trend tests were significant for invasive breast cancer (P for trend < 0.0001) and breast DCIS (P for trend < 0.001) for both percentage density and dense area.

Conclusion

The similar strength of association for mammographic density with breast DCIS and invasive breast cancer supports the hypothesis that both diseases may have a common etiology.
Up-regulation of ERK and p38 MAPK signaling pathways by hepatitis C virus E2 envelope protein in human T lymphoma cell line
Authors: Zhao Lan-Juan , Zhang Xiao-Lian , Zhao Ping , Cao Jie , Cao Ming-Mei , Zhu Shi-Ying , Liu Hou-Qi , Qi Zhong-Tian
Published: June 2006

Hepatitis C virus (HCV) infection correlates with human immune disorders characterized by abnormal activation and proliferation of lymphocytes. Interaction of HCV major envelope protein E2 with susceptible cells occurs at an early stage of the viral infection. HCV tropism for susceptible cells may elicit cellular signaling events implicated in the viral pathogenicity, and E2 protein is known to be responsible for the tropism. We documented previously that HCV E2 protein was capable of activating extracellular signal-regulated kinase (ERK) in human hepatoma Huh-7 cells. Here, ERK and p38 mitogen-activated protein kinase (MAPK) signaling pathways were investigated in human T lymphoma cell line Molt-4 in response to HCV E2 protein. Binding of HCV E2 protein to Molt-4 cells was detectable, and such interaction was a determinant for recognition and delivery of the E2 signal to intracellular pathways. Activation of ERK and p38 MAPK was specifically induced following the HCV E2-cell interaction. CD81 and low-density lipoprotein receptor (LDLR), proposed cellular receptors for HCV, were expressed naturally on Molt-4 cells. CD81 and LDLR were shown to mediate HCV E2-induced activation of ERK and p38 MAPK. In CD81-deficient U937 cells, levels of ERK and p38 MAPK activation and cell proliferation induced by HCV E2 protein were lower than those in Molt-4 cells. Furthermore, cell proliferation and secretion of interferon-γ and interleukin-10 by Molt-4 cells were promoted by HCV E2 protein. Therefore, ERK and p38 MAPK signaling pathways were up-regulated by HCV E2 protein without synergetic stimulation, which was accompanied by alterations of cell behavior.
Differential effects of statins on relevant functions of human monocyte-derived dendritic cells
Authors: Tao Jianming , Segal Brahm H , Eppolito Cheryl , Li Qingsheng , Dennis Carly G , Youn Richard , Shrikant Protul A
Published: June 2006

Invasive aspergillosis is a major cause of morbidity and mortality in the severely immunocompromised. The paucity of information about the mechanisms by which Aspergillus-derived factors regulate antigen-specific T cell responses in vivo poses a significant hurdle for devising effective immunization strategies to treat or prevent aspergillosis. By monitoring adoptively transferred T cell receptor transgenic, naive CD4+ (OT-II) and CD8+ (OT-I) T cells specific for distinct peptides of a nominal antigen, chicken ovalbumin (OVA), we demonstrate that sensitization with Aspergillus fumigatus (Af) extract plus OVA protein considerably enhances OT-I and OT-II T cell activation, which results in clonal expansion, primarily as a result of increased proliferation. The sensitization provided by Af extract promotes OT-I expansion accompanied by differentiation into interferon-γ-producing cytotoxic cells. It is surprising that no effector differentiation of the induced OT-II response was observed. Moreover, the Af extract-induced OT-I and OT-II T cell expansion was transient, as considerable contraction in the numbers of detectable OT-I and OT-II T cells was evidenced by Day 10. In agreement with these observations, sensitization with Af extract plus OVA marginally promoted host immunity against an OVA-expressing thymoma (E.G7) challenge, and the protection was enhanced by resensitization with Af extract and OVA. Our results demonstrate the ability of Af extract to differentially regulate antigen-specific CD4+ and CD8+ T cell responses, resulting in limited augmentation of host immunity. This information suggests that strategies to target CD4+ T cell effector maturation may promote host immunity to Aspergillus and unexpectedly demonstrates the use for Af extract as a CD8+ T cell adjuvant.
Passively acquired membrane proteins alter the functional capacity of bovine polymorphonuclear cells
Authors: Whale Tyler A , Wilson Heather L , Tikoo Suresh K , Babiuk Lorne A , Griebel Philip J
Published: June 2006

We have previously shown that bovine polymorphonuclear cells (PMNs) have an impressive capacity to passively acquire membrane lipids and proteins from apoptotic cells. The present study used confocal microscopy to analyze the interaction between PMNs and a variety of donor cells, and assays were used to determine if passively acquired membrane proteins altered PMN biology. Confocal microscopy revealed that direct cell–cell contact and microparticles shed by donor cells may be a source of passively acquired membranes and integral membrae proteins, which then integrate into the PMN plasma membrane. Donor cells expressing green fluorescent protein in their cytoplasm were also used to demonstrate the transfer of cytoplasmic proteins from donor cells to PMNs. The functional consequences of passive membrane protein acquisition by PMNs were then investigated using two distinct systems. First, PMNs were incubated with membranes isolated from an adenovirus-permissive cell line, and this passive transfer of cell membranes significantly increased adenovirus infection of PMNs. Second, major histocompatibility complex (MHC) class II molecules were passively transferred from ovine B cells to bovine PMNs, and PMNs with ovine MHC class II on their surface were able to induce a proliferative response and increased cytokine gene expression in alloreactive bovine T cell lines. In conclusion, passively acquired membrane proteins integrated into the plasma membrane of bovine PMNs and altered the functional capacity of these cells.
Paneth cells: leukocyte-like mediators of innate immunity in the intestine
Authors: Keshav Satish
Published: June 2006

Paneth cells are secretory intestinal epithelial cells located at the base of the crypts of Lieberkühn in the small intestine. They display prominent cytoplasmic granules, containing antibacterial proteins such as lysozyme, secretory phospholipase A2 type IIA, and α-defensins, which are released into the intestinal lumen in response to a range of stimuli. In this, they resemble circulating leukocytes, which also elaborate and secrete lysozyme and α-defensins as part of an antibacterial defense function, and the resemblance is sustained at other levels. The cells also strongly and specifically express the NOD2 gene product, one of an emerging family of critical, intracellular mediators of innate immune responses, which is also highly expressed in peripheral blood mononuclear cells, and they express RNA for tumor necrosis factor α, a major myelomonocytic cell-derived cytokine, which has a crucial role in the pathogenesis of diseases such as rheumatoid arthritis and Crohn's disease (CD). Thus, these cells, which are derived from the pluripotent intestinal epithelial stem-cell lineage, are sessile, resident host-defense cells, which may share with leukocytes the beneficial function of secreting antimicrobial peptides, aswell as the potentially harmful capacity for promoting inflammation and tissue damage. Paneth cells are most abundant in the distal small intestine, which is the region most frequently affected by CD, and there is great interest in the potential role of these cells in this condition. This brief review summarizes current knowledge and speculates on how the study of these fascinating cells might be advanced.
The human cationic host defense peptide LL-37 mediates contrasting effects on apoptotic pathways in different primary cells of the innate immune system
Authors: Barlow Peter G , Li Yuexin , Wilkinson Thomas S , Bowdish Dawn M E , Lau Y Elaine , Cosseau Celine , Haslett Christopher , Simpson A John , Hancock Robert E W , Davidson Donald J
Published: June 2006

The human cathelicidin LL-37 is a cationic host defense peptide (antimicrobial peptide) expressed primarily by neutrophils and epithelial cells. This peptide, up-regulated under conditions of inflammation, has immunomodulatory and antimicrobial functions. We demonstrate that LL-37 is a potent inhibitor of human neutrophil apoptosis, signaling through P2X7 receptors and G-protein-coupled receptors other than the formyl peptide receptor-like-1 molecule. This process involved modulation of Mcl-1 expression, inhibition of BID and procaspase-3 cleavage, and the activation of phosphatidylinositol-3 kinase but not the extracellular signal-regulated kinase 1/2 mitogen-activated protein kinase pathway. In contrast to the inhibition of neutrophil apoptosis, LL-37 induced apoptosis in primary airway epithelial cells, demonstrating alternate consequences of LL-37-mediated modulation of apoptotic pathways in different human primary cells. We propose that these novel immunomodulatory properties of LL-37 contribute to peptide-mediated enhancement of innate host defenses against acute infection and are of considerable significance in the development of such peptides and their synthetic analogs as potential therapeutics for use against multiple antibiotic-resistant infectious diseases.
Mucosal IL-8 and TGF-β recruit blood monocytes: evidence for cross-talk between the lamina propria stroma and myeloid cells
Authors: Smythies Lesley E , Maheshwari Akhil , Clements Ronald , Eckhoff Devin , Novak Lea , Vu Huong L , Mosteller-Barnum L Meg , Sellers Marty , Smith Phillip D
Published: June 2006

The lamina propria of the gastrointestinal mucosa contains the largest population of mononuclear phagocytes in the body, yet little is known about the cellular mechanisms that regulate mononuclear cell recruitment to noninflamed and inflamed intestinal mucosa. Here, we show that intestinal macrophages do not proliferate. We also show that a substantial proportion of intestinal macrophages express chemokine receptors for interleukin (IL)-8 and transforming growth factor-β (TGF-β), and a smaller proportion expresses receptors for N-formylmethionyl-leucyl-phenylalanine and C5a, but, surprisingly, they do not migrate to the corresponding ligands. In contrast, autologous blood monocytes, which express the same receptors, do migrate to the ligands. Blood monocytes also migrate to conditioned medium (CM) derived from lamina propria extracellular matrix, which we show contains IL-8 and TGF-β that are produced by epithelial cells and lamina propria mast cells. This migration is specific to IL-8 and TGF-β, as preincubation of the stroma-CM with antibodies to IL-8 and TGF-β significantly blocked monocyte chemotaxis to the stromal products. Together, these findings indicate that blood monocytes are the exclusive source of macrophages in the intestinal mucosa and underscore the central role of newly recruited blood monocytes in maintaining the macrophage population in noninflamed mucosa and in serving as the exclusive source of macrophages in inflamed mucosa.
Moderate antiangiogenic activity by local, transgenic expression of endostatin in Rip1Tag2 transgenic mice
Authors: Schaffhauser Birgit , Veikkola Tanja , Strittmatter Karin , Antoniadis Helena , Alitalo Kari , Christofori Gerhard
Published: June 2006

Many previous reports have demonstrated that systemic administration of endostatin (ES), a proteolytic cleavage product of collagen type XVIII and an endogenous angiogenesis inhibitor, represses tumor angiogenesis in different preclinical tumor models with varying efficacy. For example, systemic delivery of recombinant ES to rat insulin promoter 1 (Rip1)T-antigen 2 (Tag2)-transgenic mice, a mouse model of pancreatic β-cell carcinogenesis, has repressed tumor angiogenesis efficiently and with it, tumor growth. Here, we report that the transgenic expression of ES in Rip1ES-transgenic mice only interferes moderately with tumor growth in Rip1Tag2;Rip1ES double-transgenic mice. Tumor incidence is not reduced by the local expression of ES, and tumor outgrowth and progression to tumor malignancy are only retarded slightly. A significant effect of local ES expression on tumor angiogenesis is only apparent during the early stages of tumor development, where less angiogenic hyperplastic lesions are observed. Although efficiently produced and secreted by transgenic β cells, locally expressed ES appears to be sequestered in the microenvironment, and its systemic levels are not increased. The results indicate that the antiangiogenic functions of ES critically depend on the mode of delivery and the site of expression: although its systemic application represses tumor angiogenesis and tumor growth efficiently, locally expressed ES appears to be less effective, and hence, additional mechanisms of solubilization or activation of latent ES seem to be required. These results have important implications about the modes of delivery used in antiangiogenic, therapeutic strategies, which are based on the antiangiogenic activities of ES.
Tumor and lymph node lymphangiogenesis—impact on cancer metastasis
Authors: Tobler Nadja E , Detmar Michael
Published: June 2006

The extent of lymph node (LN) metastasis is a major determinant for the staging and the prognosis of most human malignancies and often guides therapeutic decisions. Although the clinical significance of LN involvement is well documented, little has been known about the molecular mechanisms that promote tumor spread via lymphatic vessels to sentinel and distal LN and beyond. However, recent discoveries have identified novel lymphatic-specific markers, and the newly discovered lymphangiogenesis factors vascular endothelial growth factor-C (VEGF-C) and VEGF-D were found to promote tumor-associated lymphatic vessel growth in mouse tumor models, leading to enhanced tumor spread to sentinel LN. Our recent findings indicate that VEGF-A also acts as a potent tumor lymphangiogenesis factor that promotes lymphatic tumor spread. VEGF-A overexpressing primary tumors induced sentinel LN lymphangiogenesis even before metastasizing and maintained their lymphangiogenic activity after metastasis to draining LN. Our recent studies showed that primary human melanomas that later metastasized were characterized by increased lymphangiogenesis and that the degree of tumor lymphangiogenesis can serve as a novel predictor of LN metastasis and overall patient survival, independently of tumor thickness. Tumor lymphangiogenesis also significantly predicted the presence of sentinel LN metastases at the time of surgical excision of the primary melanoma. Together, these findings suggest that tumor lymphangiogenesis actively contributes to cancer dissemination, that blockade of lymphatic vessel growth might inhibit tumor metastasis to LN, and that the extent of tumor-associated lymphangiogenesis could serve as a novel, prognostic parameter for the metastatic risk of human cancers.
The source of APRIL up-regulation in human solid tumor lesions
Authors: Mhawech-Fauceglia P , Kaya G , Sauter G , McKee T , Donze O , Schwaller J , Huard B
Published: June 2006

Abundant mRNA expression for a proliferation-inducing ligand (APRIL) from tumor necrosis factor (TNF) family is observed in many solid tumors. Here, we analyzed in situ the cellular source of APRIL in human solid tumors with anti-APRIL antibodies. In most cases, neutrophils present in the tumor stroma constituted the main source of APRIL. In cutaneous lesions such as melanoma or basal cell carcinoma, tumor-adjacent keratinocytes also produced APRIL. APRIL production by tumor cells themselves was a rare event, only observed in urothelial bladder cancer and squamous cell carcinoma. Detailed analysis revealed that APRIL dissociated from producing cells, and secreted APRIL was retained in the tumor lesions. A direct binding onto tumor cells via heparan sulfate proteoglycans (HSPG) was observed in in vitro experiments and confirmed in situ. Taken together, our analysis indicates a potential role for HSPG/APRIL interactions in the development of solid tumors.
Cloning and Characterization of an Ovine Intracellular Seven Transmembrane Receptor for Progesterone that Mediates Calcium Mobilization
Authors: Ashley R. L. , Clay C. M. , Farmerie T. A. , Niswender G. D. , Nett T. M.
Published: June 2006

Classically, progesterone has been thought to act only through the well-known genomic pathway involving hormone binding to nuclear receptors (nPR) and subsequent modulation of gene expression. However, there is increasing evidence for rapid, nongenomic effects of progesterone in a variety of tissues in mammals, and it seems likely that a membrane PR (mPR) is causing these events. The objective of this study was to isolate and characterize an ovine mPR distinct from the nPR. A cDNA clone was isolated from ovine genomic DNA by PCR. The ovine mPR is a 350-amino acid protein that, based on computer hydrophobicity analysis, possesses seven transmembrane domains and is distinct from the nPR. Message for the ovine mPR was detected in hypothalamus, pituitary, uterus, ovary, and corpus luteum by RT-PCR. In CHO cells that overexpressed a mPR-green fluorescent protein fusion protein, the ovine mPR was localized to the endoplasmic reticulum and not the plasma membrane. Specific binding of 3H-progesterone to membrane fractions was demonstrated in CHO cells that expressed the ovine mPR but not in nontransfected cells. Furthermore, progesterone and 17α-hydroxy-progesterone stimulated intracellular Ca2+ mobilization in CHO cells that expressed ovine mPR in Ca2+-free medium (P < 0.05) but not in CHO cells transfected with empty vector. This rise in intracellular Ca2+ is believed to be from the endoplasmic reticulum as intracellular Ca2+ mobilization is absent when mPR transfected cells are first treated with thapsigargin to deplete Ca2+ stores from the endoplasmic reticulum. Isolation, identification, tissue distribution, cellular localization, steroid binding, and a functional response for a unique intracellular mPR in the sheep are presented.
Increased Pro-Nerve Growth Factor and p75 Neurotrophin Receptor Levels in Developing Hypothyroid Rat Cerebral Cortex Are Associated with Enhanced Apoptosis
Authors: Kumar Ashok , Sinha Rohit Anthony , Tiwari Meenakshi , Pal Lily , Shrivastava Ashutosh , Singh Rajesh , Kumar Krishna , Kumar Gupta Sushil , Godbole Madan M.
Published: June 2006

Thyroid hormone insufficiency adversely affects cortical development; however, its effect on apoptosis modulation during cerebral cortex development is not understood. We investigated the effect of perinatal hypothyroidism on apoptosis and its mechanisms during rat cerebral cortex development. Primary hypothyroidism was induced by feeding methimazole (0.025% wt/vol) in the drinking water to pregnant and lactating rats and continued until the animals were killed (hypothyroid group). Cerebral cortices from pups were harvested at different postnatal ages (postnatal d 0, 8, 16, and 24 and adult), and apoptosis was quantitated by terminal deoxynucleotide transferase-mediated dUTP nick end labeling and cleaved caspase-3 immunoreactivity. Compared with the euthyroid, primary somatosensory cortex (S1) in the hypothyroid group exhibited enhanced apoptosis. In S1 of euthyroid rats, apoptotic cells were mostly found in cortical layers I–III and the proportion of apoptotic cells enhanced significantly in the hypothyroid group (P < 0.001). Most of the apoptotic cells were neurons, as assessed by double immunolabeling. A significantly increased activation of caspase-3 and -7, decreased levels of antiapoptotic proteins Bcl-2 and Bcl-xL, and increased levels of proapoptotic protein Bax was observed in the developing cerebral cortex of hypothyroid rats, compared with the euthyroid (P < 0.001). In addition, hypothyroidism significantly elevated the levels of 53-kDa pro-nerve growth factor (P < 0.001) and p75 neurotrophin receptor (P < 0.001) and decreased TrkA expression. Taken together, we provide evidence for the possible contribution of pro-nerve growth factor/p75 neurotrophin receptor pathway in hypothyroidism-enhanced apoptosis during rat cortical development. Thus, the present study may help in explaining the mechanism of the deleterious effect of thyroid hormone deficiency on cerebral cortex development in children.
Mouse Sterol Response Element Binding Protein-1c Gene Expression Is Negatively Regulated by Thyroid Hormone
Authors: Hashimoto Koshi , Yamada Masanobu , Matsumoto Shunichi , Monden Tsuyoshi , Satoh Teturou , Mori Masatomo
Published: June 2006

Sterol regulatory element-binding protein (SREBP)-1c is a key regulator of fatty acid metabolism and plays a pivotal role in the transcriptional regulation of different lipogenic genes mediating lipid synthesis. In previous studies, the regulation of SREBP-1c mRNA levels by thyroid hormone has remained controversial. In this study, we examined whether T3 regulates the mouse SREBP-1c mRNA expression. We found that T3 negatively regulates the mouse SREBP-1c gene expression in the liver, as shown by ribonuclease protection assays and real-time quantitative RT-PCR. Promoter analysis with luciferase assays using HepG2 and Hepa1–6 cells revealed that T3 negatively regulates the mouse SREBP-1c gene promoter (−574 to +42) and that Site2 (GCCTGACAGGTGAAATCGGC) located around the transcriptional start site is responsible for the negative regulation by T3. Gel shift assays showed that retinoid X receptor-α/thyroid hormone receptor-β heterodimer bound to Site2, but retinoid X receptor-α/liver X receptor-α heterodimer could not bind to the site. In vivo chromatin immunoprecipitation assays demonstrated that T3 induced thyroid hormone receptor-β recruitment to Site2. Thus, we demonstrated that mouse SREBP-1c mRNA is down-regulated by T3in vivo and that T3 negatively regulates mouse SREBP-1c gene transcription via a novel negative thyroid hormone response element: Site2.
Indian Hedgehog, But Not Histidine Decarboxylase or Amphiregulin, Is a Progesterone-Regulated Uterine Gene in Hamsters
Authors: Khatua Atanu , Wang Xiaohong , Ding Tianbing , Zhang Qian , Reese Jeff , DeMayo Francesco J. , Paria Bibhash C.
Published: June 2006

Implantation occurs only in the progesterone (P4)-primed uterus in the majority of species, but little effort has been given to identify P4-mediated molecules in these species. Using hamsters as a model for P4-dependent implantation and three well-known uterine receptivity-associated P4-regulated genes, Indian hedgehog (Ihh), histidine decarboxylase (Hdc), and amphiregulin (Areg), in mice that require ovarian estrogen for uterine receptivity and implantation, our strategy aimed to determine whether P4 regulates uterine expression of these genes in hamsters and whether the event- and cell-specific uterine expression patterns of these genes during the periimplantation period in hamsters follow similarly with their patterns in mice. We report here that P4-mediated Ihh signaling is important for uterine receptivity and implantation in hamsters because uterine epithelial Ihh expression was regulated by P4 and its expression patterns during the periimplantation period of hamsters closely follow its pattern in mice. In contrast, we noted no hormonal regulation of Hdc and Areg in the hamster uterus. However, this did not diminish their importance in hamsters because their expression patterns and functions are event and cell specific during the periimplantation period: whereas Hdc was expressed exclusively in d 4 uterine glands and regulated by the blastocyst, Areg was expressed on the decidual area adjacent to the embryo from d 5 onward and involved in stromal cell proliferation. We conclude that similarities and dissimilarities exist in uterine expression pattern of implantation-related genes, including hormonal regulation and their event-specific importance.
Testosterone Is Required for Delayed Cardioprotection and Enhanced Heat Shock Protein 70 Expression Induced by Preconditioning
Authors: Liu Jing , Tsang Sharon , Wong Tak Ming
Published: June 2006

Ischemic preconditioning fails to confer immediate cardioprotection in the absence of testosterone, indicating that the hormone is required for the process. Here we set out to determine whether testosterone is also necessary for delayed cardioprotection and, if so, how it acts. Male Sprague Dawley rats (7–8 wk) underwent sham operation or gonadectomy without (G) or with testosterone replacement (GT) for 8 wk. Isolated ventricular myocytes were preconditioned either by metabolic inhibition or with U50,488H, a κ-opioid receptor agonist. In intact rats, U50,488H was administered systemically and 24 h later the hearts were removed. Ventricular myocytes were then subjected to metabolic inhibition and anoxia and isolated hearts to regional ischemia, followed by reperfusion to induce injury. Both types of preconditioning significantly increased the viability and decreased the lactate dehydrogenase release in ventricular myocytes from sham rats. They also activated heat shock transcription factor-1 and increased heat shock protein 70 expression. In contrast, all these effects were absent in myocytes from G rats and were restored by testosterone replacement. Parallel results were found in isolated hearts. In addition, preconditioning improved contractile functions impaired by ischemic insults in sham and rats gonadectomized with testosterone replacement but not G rats. The effects of testosterone replacement in ventricular myocytes were abolished by androgen receptor blockade. In conclusion, preconditioning requires testosterone to increase heat shock protein 70 synthesis, which mediates delayed cardioprotection in the male. These effects of testosterone are mediated by the androgen receptor.
Sphingosine 1-Phosphate Affects Cytokine-Induced Apoptosis in Rat Pancreatic Islet β-Cells
Authors: Laychock Suzanne G. , Sessanna Shawn M. , Lin Mei-Hui , Mastrandrea Lucy D.
Published: June 2006

Cytokines mediate pancreatic islet β-cell apoptosis and necrosis, leading to loss of insulin secretory capacity and type 1 diabetes mellitus. The cytokines, IL-1β and interferon-γ, induced terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) staining of rat islet cells within 48 h by about 25–30%, indicative of apoptosis and/or necrosis. Sphingosine 1-phosphate (S1P) at nanomolar concentrations significantly reduced islet cell cytokine-induced TUNEL staining. Similar effects were observed in INS-1 cells. The dihydro analog of S1P also reduced the percentage of TUNEL stained islet and INS-1 cells, whereas the S1P receptor antagonist BML-241 blocked the protective effects. Pertussis toxin did not affect the S1P protective response. In the presence of a phospholipase C antagonist, U73122, there was significant inhibition of the S1P protective effects against apoptosis/necrosis. S1P stimulated INS-1 cell protein kinase C activity. Carbamylcholine chloride acting through muscarinic receptors also inhibited cytokine-induced TUNEL staining in pancreatic islet cells. S1P and/or dihydro-S1P also antagonized cytokine-induced increases in cytochrome c release from mitochondria and caspase-3 activity in INS-1 cells, which are indicative of cell apoptosis vs. necrosis. S1P failed to affect nitric oxide synthase activity after 48 h. Thus, the evidence suggests that S1P acting on S1P receptors coupled to Gq mediates protective effects on islet β-cells against cytokine-induced apoptosis.
Bcl-xL Is Overexpressed in Hormone-Resistant Prostate Cancer and Promotes Survival of LNCaP Cells via Interaction with Proapoptotic Bak
Authors: Castilla Carolina , Congregado Belén , Chinchón David , Torrubia Francisco J. , Japón Miguel A. , Sáez Carmen
Published: June 2006

Androgen-sensitive prostate cancer cells turn androgen resistant through complex mechanisms that involve dysregulation of apoptosis. We investigated the role of antiapoptotic Bcl-xL in the progression of prostate cancer as well as the interactions of Bcl-xL with proapoptotic Bax and Bak in androgen-dependent and -independent prostate cancer cells. Immunohistochemical analysis was used to study the expression of Bcl-xL in a series of 139 prostate carcinomas and its association with Gleason grade and time to hormone resistance. Expression of Bcl-xL was more abundant in prostate carcinomas of higher Gleason grades and significantly associated with the onset of hormone-refractory disease. In vivo interactions of Bcl-xL with Bax or Bak in untreated and camptothecin-treated LNCaP and PC3 cells were investigated by means of coimmunoprecipitation. In the absence of any stimuli, Bcl-xL interacts with Bax and Bak in androgen-independent PC3 cells but only with Bak in androgen-dependent LNCaP cells. Interactions of Bcl-xL with Bax and Bak were also evidenced in lysates from high-grade prostate cancer tissues. In LNCaP cells treated with camptothecin, an inhibitor of topoisomerase I, the interaction between Bcl-xL and Bak was absent after 36 h, Bcl-xL decreased gradually and Bak increased coincidentally with the progress of apoptosis. These results support a model in which Bcl-xL would exert an inhibitory effect over Bak via heterodimerization. We propose that these interactions may provide mechanisms for suppressing the activity of proapoptotic Bax and Bak in prostate cancer cells and that Bcl-xL expression contributes to androgen resistance and progression of prostate cancer.
Treatment of Autoimmune Hyperthyroidism in a Murine Model of Graves’ Disease with Tumor Necrosis Factor-Family Ligand Inhibitors Suggests a Key Role for B Cell Activating Factor in Disease Pathology
Authors: Gilbert Jacqueline A. , Kalled Susan L. , Moorhead Jane , Hess Donna M. , Rennert Paul , Li Zhifang , Khan M. Zareen , Banga J. Paul
Published: June 2006

Hyperthyroid Graves’ disease is a common autoimmune disorder mediated by agonistic antibodies to the TSH receptor, termed thyroid stimulating antibodies (TSAbs). Recently members of the TNF superfamily, B cell activating factor (BAFF) and a proliferation-inducing ligand (APRIL), have been identified along with their receptors, B cell maturation antigen and transmembrane activator and calcium-modulator and cyclophilin ligand interactor, and the BAFF-specific receptor. BAFF is a fundamental B cell survival/maturation factor, and both BAFF and APRIL have been implicated in antibody production. We investigated the effect of interfering with BAFF- and APRIL-mediated signals in an induced model of Graves’ disease by blockade of these factors using soluble decoy receptors. In a therapeutic setting in mice with established hyperthyroidism, we show that blockade of BAFF or BAFF+APRIL with BAFF-specific receptor-Fc and B cell maturation antigen-Fc, respectively, leads to significant reductions in the induced hyperthyroidism. This was supported by a parallel pattern of declining TSAbs in the responding animals. Histopathological analysis of splenic sections from treated animals revealed marked reductions in the B cell follicle regions, but staining with anti-CD138 revealed the persistence of plasma cells. Thus, the reductions in TSAbs in the treated animals were not related to overall plasma cell numbers in the secondary lymphoid organs. Our results are the first to demonstrate attenuation of established hyperthyroidism by therapeutic intervention aimed at autoreactive B cells and indicate that both BAFF and APRIL appear to play important roles in the development and survival of the autoantibody producing cells in this model.
The use of hydroxyapatite-coated CAD-CAM femoral components in adolescents and young adults with inflammatory polyarthropathy
Authors: McCullough C. J. , Remedios D. , Tytherleigh-Strong G. , Hua J. , Walker P. S.
Published: June 2006

Between June 1991 and January 1995, 42 hydroxyapatite-coated CAD-CAM femoral components were inserted in 25 patients with inflammatory polyarthropathy, 21 of whom had juvenile idiopathic arthritis. Their mean age was 21 years (11 to 35). All the patients were reviewed clinically and radiologically at one, three and five years. At the final review at a mean of 11.2 years (8 to 13) 37 hips in 23 patients were available for assessment.

A total of four femoral components (9.5%) had failed, of which two were radiologically loose and two were revised. The four failed components were in patients aged 16 years or less at the time of surgery. Hydroxyapatite-coated customised femoral components give excellent medium- to long-term results in skeletally-mature young adults with inflammatory polyarthropathy. Patients aged less than 16 years at the time of surgery have a risk of 28.5% of failure of the femoral component at approximately ten years.
A comparison of two biomaterial carriers for osteogenic protein-1 (BMP-7) in an ovine critical defect model
Authors: Pluhar G. E. , Turner A. S. , Pierce A. R. , Toth C. A. , Wheeler D. L.
Published: June 2006

Critical size defects in ovine tibiae, stabilised with intramedullary interlocking nails, were used to assess whether the addition of carboxymethylcellulose to the standard osteogenic protein-1 (OP-1/BMP-7) implant would affect the implant’s efficacy for bone regeneration. The biomaterial carriers were a ‘putty’ carrier of carboxymethylcellulose and bovine-derived type-I collagen (OPP) or the standard with collagen alone (OPC). These two treatments were also compared to “ungrafted” negative controls. Efficacy of regeneration was determined using radiological, biomechanical and histological evaluations after four months of healing. The defects, filled with OPP and OPC, demonstrated radiodense material spanning the defect after one month of healing, with radiographic evidence of recorticalisation and remodelling by two months. The OPP and OPC treatment groups had equivalent structural and material properties that were significantly greater than those in the ungrafted controls. The structural properties of the OPP- and OPC-treated limbs were equivalent to those of the contralateral untreated limb (p > 0.05), yet material properties were inferior (p < 0.05). Histopathology revealed no residual inflammatory response to the biomaterial carriers or OP-1. The OPP- and OPC-treated animals had 60% to 85% lamellar bone within the defect, and less than 25% of the regenerate was composed of fibrous tissue. The defects in the untreated control animals contained less than 40% lamellar bone and more than 60% was fibrous tissue, creating full cortical thickness defects. In our studies carboxymethylcellulose did not adversely affect the capacity of the standard OP-1 implant for regenerating bone.
The incidence of deep prosthetic infections in a specialist orthopaedic hospital
Authors: Phillips J. E. , Crane T. P. , Noy M. , Elliott T. S. J. , Grimer R. J.
Published: June 2006

The Control of Infection Committee at a specialist orthopaedic hospital prospectively collected data on all episodes of bacteriologically-proven deep infection arising after primary hip and knee replacements over a 15-year period from 1987 to 2001.

There were 10 735 patients who underwent primary hip or knee replacement. In 34 of 5947 hip replacements (0.57%) and 41 of 4788 knee replacements (0.86%) a deep infection developed. The most common infecting micro-organism was coagulase-negative staphylococcus, followed by Staphylococcus aureus, enterococci and streptococci. Of the infecting organisms, 72% were sensitive to routine prophylactic antimicrobial agents.

Of the infections, 29% (22) arose in the first three months following surgery, 35% between three months and one year (26), and 36% (27) after one year. Most cases were detected early and treated aggressively, with eradication of the infection in 96% (72). There was no significant change in the infection rate or type of infecting micro-organism over the course of this study.

These results set a benchmark, and importantly emphasise that only 64% of peri-prosthetic infections arise within one year of surgery. These results also illustrate the advantages of conducting joint replacement surgery in the isolation of a specialist hospital.
Low tibial osteotomy for varus-type osteoarthritis of the ankle
Authors: Tanaka Y. , Takakura Y. , Hayashi K. , Taniguchi A. , Kumai T. , Sugimoto K.
Published: June 2006

In this retrospective study we have assessed the results of low tibial valgus osteotomy for varus-type osteoarthritis of the ankle and its indications.

We performed an opening wedge osteotomy in 25 women (26 ankles). The mean follow-up was for eight years and three months (2 years 3 months to 17 years 11 months).

Of the 26 ankles, 19 showed excellent or good clinical results. Their mean scores for pain, walking, and activities of daily living were significantly improved but there was no change in the range of movement. In the ankles which were classified radiologically as stage 2 according to our own grading system, with narrowing of the medial joint space, and in 11 as stage 3a, with obliteration of the joint space at the medial malleolus only, the joint space recovered. In contrast, such recovery was seen in only two of 12 ankles classified as stage 3b, with obliteration of the joint space advancing to the upper surface of the dome of the talus. Low tibial osteotomy is indicated for varus-type osteoarthritis of stage 2 or stage 3a.
Kudo type-5 total elbow arthroplasty in mutilating rheumatoid arthritis
Authors: Mori T. , Kudo H. , Iwano K. , Juji T.
Published: June 2006

We studied 11 patients (14 elbows) with gross rheumatoid deformity of the elbow, treated by total arthroplasty using the Kudo type-5 unlinked prosthesis, and who were evaluated between five and 11 years after operation. Massive bone defects were augmented by autogenous bone grafts. There were no major complications such as infection, subluxation or loosening. In most elbows relief from pain and stability were achieved. The results, according to the Mayo Elbow Performance Score, were excellent in eight, good in five and fair in one. In most elbows there was minimal or no resorption of the grafted bone. There were no radiolucent lines around the stems of the cementless components. This study shows that even highly unstable rheumatoid elbows can be replaced successfully using an unlinked prosthesis, with augmentation by grafting for major defects of bone.
Pedicle subtraction osteotomy for rigid post-tuberculous kyphosis
Authors: Kalra K. P. , Dhar S. B. , Shetty G. , Dhariwal Q.
Published: June 2006

We studied 15 patients with healed tuberculosis of the spine and a resultant kyphosis. We selected only those with no neurological deficit and performed a wedge resection of the vertebra using a transpedicular approach. The wedge was removed from the apex of the deformity. For those with a neurological deficit, we chose the conventional anterior debridement and decompression with 360° circumferential fusion. At a mean follow-up of 26.8 months (8 to 46) the outcome was good with an increase in the mean Oswestry Disability Index from 56.26 (48 to 62) pre-operatively to 11.2 (6 to 16) at the latest follow-up.
Computer navigation of the acetabular component
Authors: Spencer J. M. F. , Day R. E. , Sloan K. E. , Beaver R. J.
Published: June 2006

Our aim was to assess the intra- and inter-observer reliability in the establishment of the anterior pelvic plane used in imageless computer-assisted navigation. From this we determined the subsequent effects on version and inclination of the acetabular component.

A cadaver model was developed with a specifically-designed rod which held the component tracker at a fixed orientation to the pelvis, leaving the anterior pelvic plane as the only variable. Eight surgeons determined the anterior pelvic plane by palpating and registering the bony landmarks as reference points. The exact anterior pelvic plane was then established by using anatomically-placed bone screws as reference points.

The difference between the surgeons was found to be highly significant (p < 0.001). The variation was significantly larger for anteversion (sd 9.6°) than for inclination (sd 6.3°). The present method for registering pelvic landmarks shows significant inaccuracy, which highlights the need for improved methods of registration before this technique is considered to be safe.
Arthrodesis versus Mayo resection
Authors: Grondal L. , Broström E. , Wretenberg P. , Stark A.
Published: June 2006

In a prospective randomised study 31 patients were allocated to either arthrodesis or Mayo resection of the first metatarsophalangeal joint as part of a total reconstruction of the rheumatoid forefoot. Of these, 29 were re-examined after a mean of 72 months (57 to 80), the Foot Function Index was scored and any deformity measured. Load distribution was analysed using a Fscan mat in 14 cases, and time and distance were measured in 12 of these patients using a 3D Motion system. We found excellent patient satisfaction and a significant, lasting reduction of the Foot Function Index, with no statistically significant differences between the groups. There were no significant differences in recurrence of the deformity, the need for special shoes, gait velocity, step length, plantar moment, mean pressure or the position of the centre of force under the forefoot. The cadence was higher and the stance phase shorter in the fusion group.

These results suggest that a Mayo resection may be an equally good option for managing the first metatarsophalangeal joint in reconstruction of the rheumatoid forefoot.
The transverse acetabular ligament: an aid to orientation of the acetabular component during primary total hip replacement
Authors: Archbold H. A. P. , Mockford B. , Molloy D. , McConway J. , Ogonda L. , Beverland D.
Published: June 2006

Ensuring the accuracy of the intra-operative orientation of the acetabular component during a total hip replacement can be difficult. In this paper we introduce a reproducible technique using the transverse acetabular ligament to determine the anteversion of the acetabular component. We have found that this ligament can be identified in virtually every hip undergoing primary surgery. We describe an intra-operative grading system for the appearance of the ligament. This technique has been used in 1000 consecutive cases. During a minimum follow-up of eight months the dislocation rate was 0.6%. This confirms our hypothesis that the transverse acetabular ligament can be used to determine the position of the acetabular component. The method has been used in both conventional and minimally-invasive approaches.
Management of complex tibial and femoral nonunion using the Ilizarov technique, and its cost implications
Authors: Patil S. , Montgomery R.
Published: June 2006

We reviewed 78 femoral and tibial nonunions treated between January 1992 and December 2003. Of these, we classified 41 in 40 patients as complex cases because of infection (22), bone loss (6) or failed previous surgery (13). The complex cases were all treated with Ilizarov frames. At a mean time of 14.1 months (4 to 38), 39 had healed successfully.

Using the Association for the Study and Application of the Methods of Ilizarov scoring system we obtained 17 excellent, 14 good, four fair and six poor bone results. The functional results were excellent in 14 patients, good in 14, fair in two and poor in two. A total of six patients were lost to follow-up and two had amputations so were not evaluated for final functional assessment. All but two patients were very satisfied with the results. The average cost of treatment to the treating hospital was approximately £30 000 per patient.

We suggest that early referral to a tertiary centre could reduce the morbidity and prolonged time off work for these patients. The results justify the expense, but the National Health Service needs to make financial provision for the reconstruction of this type of complex nonunion.
Differentiation of Selected Salmonella Enterica Serovars by Fourier Transform Mid-Infrared Spectroscopy
Authors: Baldauf Nathan A. , Rodriguez-Romo Luis A. , Yousef Ahmed E. , Rodriguez-Saona Luis E.
Published: June 2006

Salmonella enterica serovars include pathogens responsible for high numbers of foodborne salmonellosis. Fourier transform infrared (FT-IR) spectroscopy can be used to rapidly and accurately identify microorganisms based on unique spectra of bacterial cell components. The objectives of this study were to discriminate closely related Salmonella enterica serovars by using FT-IR spectroscopy and multivariate analysis and to compare the performance of three techniques for differentiating among Salmonella serovars. Selected serovars of S. enterica were streaked onto plate count agar and incubated (37 °C, 24 h). Isolated colonies were suspended in phosphate buffer or 50% ethanol (10 μL). Suspensions were placed on (1) ZnSe crystals for transmission, (2) disposable polyethylene membranes (DPM) for transmission, and (3) diamond crystal plate for attenuated total reflectance (ATR) analyses; all samples were dried under vacuum. Classification models, soft independent modeling of class analogy (SIMCA), from derivatized infrared spectra (1300–900 cm−1), discriminated among Salmonella serovars presumably attributed to cell's lipopolysaccharides (1000–980 cm−1). Samples on DPM required high cell density for reliable spectra. High-quality spectra were obtained when a single colony was suspended in ethanol or buffer and mounted on ZnSe crystals for transmission or diamond plate for ATR analysis. Prediction of unknowns, representative of serovars used to construct classification models, showed that all techniques were suitable for the rapid and accurate differentiation of Salmonella serovars.