Common Pathological Phenomenon Research Articles

Development, Test and Validation of a Mechatronic Device for Spasticity Quantification

Abstract Spasticity is a common pathological phenomenon in clinical practices, frequently expressed as a stroke, multiple sclerosis or cerebral palsy. The accurate quantification of spasticity allows early action to prevent the potentially irreversible consequences. The aim of this work is to develop and implement a mechatronic device for the accurate quantification of spasticity, which is able to differentiate spasticity from other motor disorders. The proposed method is based on the quantification of the tonic stretch reflex threshold (TSRT) for the assessment of the range of motion of the limb affected by spasticity. In order to validate the developed device, experimental trials have been conducted, considering the flexor muscle of the elbow joint. The developed device was tested, first in a laboratory environment with healthy subjects and secondly, in a clinical environment with the collaboration of patients with spasticity. The evaluations in th clinical environment were performed on three different days in order to evaluate the reproducibility of the obtained results. The experimental trials confirm the sensibility, reproducibility and reliability of spasticity quantification based on the TSRT method. This project has been developed in cooperation with the Hospital of Braga and Fisimaia rehabilitation clinic, both in Portugal.

P-0095 Sonic Hedgehog Paracrine Signaling Activates Pancreatic Stellate Cells to Promote The Perineural Invasion of Pancreatic Cancer in Vivo

IntroductionPerineural invasion (PNI) in pancreatic adenocarcinoma (PADC) is a common pathological phenomenon in which cancer cells invade and intimately contact the endoneuria of pancreatic nerves and is thought to contribute to both pain and local disease recurrence. PNI is an important prognostic factor for PADC that increases as the cancer becomes undifferentiated and predominantly existed in the perineurium and perineural space. It has been shown that the tumor-stroma microenvironment is an important regulator of cancer cell behavior. We hypothesized that the adjacent pancreatic stellate cells (PSC) activated by paracrine sonic hedgehog (SHH) which derived from PADC cells play important roles in creating a dynamic environment that supports pancreatic tumor growth and invasion, thus ultimately induced PNI. This study is aimed to evaluate the important function of pancreatic stellate cells in PNI of PADC. MethodsAsPc-1, a human PADC line expressing high Shh protein were stably transfect with SHH shRNA or empty plasmid. Stable transfectants were confirmed by western blot. Six-week-old male athymic nude mice were anesthetized with inhalational methoxyflurane for all procedures and the left sciatic nerve was exposed deep to the femoracoccygeus and biceps femoris muscles. Cells were microscopically injected into the perineurium of the sciatic nerve, distal to the bifurcation of the tibial and common peroneal nerves. 3 µL of AsPc-1 or AsPc-1-SHH- and PSC suspension at a concentration of 1×108/&mgr;L was co-injected slowly. Sciatic nerve–infiltrating tumors were established and animals were observed for up to 6 weeks for assessment of tumor size, nerve function including the gross behavior, the limb function, and sciatic nerve function index. ResultsAfter 3 weeks of injection, the nerve function including the gross behavior, the limb function, and sciatic nerve function index were worse in the AsPc-1 plus PSC group compared with the AsPc-1-SHH- plus PSC or AsPc-1 alone group (P<0.05). Additionally, the tumor diameter at the implantation site was larger in the AsPc-1 plus PSC group compared with the AsPc-1-SHH- plus PSC or AsPc-1 alone group (P<0.05) due to massive tumor growth. Furthermore, the proximal nerve diameter was larger in the AsPc-1 plus PSC group compared with the AsPc-1-SHH- plus PSC or AsPc-1 alone group (P<0.05) due to extensive infiltration by cancer cells. ConclusionThese data provide evidence for SHH, derived from pancreatic tumor epithelia, may be critical in regulating the tumor microenvironment and thereby contributes to PNI of PADC, which may have important implications for potential therapy directed against PNI.

Interplay of protein misfolding pathway and unfolded-protein response in acute promyelocytic leukemia

Protein misfolding has traditionally been linked to the pathogenesis of various neurodegenerative diseases. However, emerging evidence from various laboratories, including ours, suggests that protein misfolding may also play a fundamental role in some malignancies, particularly those caused by fusion oncoprotein generated from chromosomal translocation. Promyelocytic leukemia (PML) fused to the retinoic acid receptor (RAR) is a fusion oncoprotein linked to the transformation of acute promyelocytic leukemia (APL), and is not only a misfolded protein itself, but also promotes misfolding of nuclear receptor corepressor (N-CoR) protein, a corepressor essential for the growth-suppressive function of several tumor-suppressor proteins. PML–RAR promotes misfolding of N-CoR by inducing aberrant post-translational modification, which destabilizes its core and promotes instability. Misfolded N-CoR, thus, contributes to differentiation arrest and survival of APL cells through loss-of-function and aberrant gain-of-function properties. Therapeutic restoration of N-CoR conformation and function with conformation-modifying agents not only releases this differentiation arrest but also sensitizes APL cells to programmed cell death. These findings illustrate the potential of the misfolded N-CoR protein as a conformation-based drugable molecular target for APL, and highlights the promise of various conformation-modifying agents as novel therapeutics for APL. Protein conformational rearrangement, resulting from an inherited or acquired genetic alteration, could be a common pathological phenomenon contributing to transformation in different types of leukemias and solid tumors and, therefore, could serve as a common ground for designing a unifying diagnostic as well as therapeutic approach for a widely diverse disease such as cancer. To that end, APL could serve as a model for the development of a novel conformation-based therapeutic approach for other malignant diseases.

MUC1 Is a Counter-Receptor for Myelin-Associated Glycoprotein (Siglec-4a) and Their Interaction Contributes to Adhesion in Pancreatic Cancer Perineural Invasion

Perineural invasion in pancreatic adenocarcinoma, a common pathologic phenomenon whereby cancer cells invade and intimately contact the endoneurium of pancreatic nerves, is thought to contribute to both pain and local disease recurrence. MUC1, a type I transmembrane mucin that can affect the adhesive properties of cells, contains a large extracellular tandem repeat domain, which is heavily glycosylated in normal epithelia, but is overexpressed and differentially glycosylated in pancreatic cancer. This altered glycosylation includes the shortened core I O-glycans for monosialyl and disialyl T antigens. Myelin-associated glycoprotein (MAG), a membrane-bound protein expressed on oligodendrocytes and Schwann cells, binds myelin to neurons. MAG's preferred ligands are derivatives of the monosialyl and disialyl T antigen. We investigated whether MUC1 is a counter-receptor for MAG and if their interaction contributed to pancreatic perineural invasion. Results showed that MAG binds pancreatic cells expressing MUC1, that this binding is sialidase-sensitive, and that MAG physically associates with MUC1. Heterotypic adhesion assays between pancreatic cancer cells and Schwann cells revealed that increased expression of MUC1 or MAG enhanced adhesion. Conversely, specific inhibition of MAG or sialyl-T MUC1 partially blocked adhesion. Immunohistochemical analysis of pancreatic perineural invasion showed the expression of both MUC1 and MAG. These results support the hypothesis that the adhesive interactions between MUC1 and MAG are of biological significance in pancreatic cancer perineural invasion.

Contribution of ovarian follicular tissue abnormalities into the development of ovarian dysfunction

Ultrastructural, in vitro radioautographic, and stereological study of the morphogenesis of ovarian cystic formations in women of reproductive age distinguished ovariopathy as a common pathological phenomenon, developing as a result of the ovarian follicular cell regenerative and plastic insufficiency syndrome. Degenerative dystrophic changes in the follicular compartment, reduced biosynthetic reactions in the follicular cells, and reactive sclerosis of the stroma remodulate the parenchyma-stromal relationships.

Use of PCR to detect Leishmania (Viannia) spp. in dog blood and bone marrow.

A PCR-based protocol for the detection of Leishmania (Viannia) parasites in canine blood, buffy coat, and bone marrow was developed and was then tested with field samples taken from a random sample of 545 dogs from villages in Peru where Leishmania (Viannia) braziliensis and Leishmania (Viannia) peruviana are endemic. Comparative tests with cultured parasites mixed with dog blood showed that the PCR assay's sensitivity was significantly dependent on the DNA extraction protocol and the PCR primers used. Mass screening of field samples by the preferred PCR protocol detected American cutaneous leishmaniasis (ACL) in 44 of 545 (8.1%) dogs; 31 of 402 (7.7%), 20 of 223 (9.0%), and 8 of 46 (17.4%) were PCR positive when whole blood, buffy coat, and bone marrow aspirates, respectively, were tested. The high prevalence of Leishmania in both asymptomatic (7.6%) and symptomatic (18.0%) dogs provides further circumstantial evidence for their suspected role as reservoir hosts of ACL and indicates that hematogenous dissemination of parasites may be a more common pathological phenomenon than has previously been acknowledged. However, unlike for zoonotic visceral leishmaniasis, the comparatively low prevalence of Leishmania (Viannia) in the blood of symptomatic dogs indicates that PCR with blood cannot be the "gold standard" for the (mass) screening of samples in epidemiological studies.