BACKGROUND: The pathological distinction between hyperplastic polyps and sessile serrated adenoma/polyps of the right colon is often difficult and may result in misdiagnosed polyps. OBJECTIVE: To review the proportion and accuracy of serrated polyp diagnosis within a one year retrospective review of colorectal polyp samples, focusing on hyperplastic polyps of the right colon, using criteria set forth by previous studies. MATERIALS & METHODS: 4096 Winnipeg patient cases from January 2009 to December 2009 were reviewed. The proportion of sessile serrated adenoma/polyps, traditional serrated adenoma and serrated adenoma were determined in the patient population. Additionally, pathological morphological variables were reassessed by two study pathologists to determine the frequency of sessile serrated adenoma/polyp initially diagnosed as hyperplastic polyps within the right colon. RESULTS: Approximately 5% of all polyps in the patient population where diagnosed as non-hyperplastic serrated polyps (SSA/P, TSA and SA) and 12.5% as hyperpalstic polyps. Of the non-hyperplastic serrated polyps, a majority were diagnosed as SA. Upon reassessment of right sided HP (n=121), 34% were re-classified as SSA/P. CONCLUSIONS: Winnipeg pathologists diagnose non-hyperplastic serrated polyps with a frequency similar to literature, but are not fully utilizing modern terminology, as majority of non-hyperplastic serrated polyps are reported as SA without further categorisation. Furthermore, a significant proportion of right sided hyperplastic polyps could be re-classified as sessile serrated adenomas on review. Given the difficulty in distinguishing sessile serrated adenomas from hyperplastic polyps, closer endoscopic surveillance should be considered for all individuals with all serrated polyps (including hyperplastic polyps) in the right colon or alternatively all such polyps should be routinely reviewed by two pathologists.

In much of the work devoted within recent years to the study of atherosclerosis, great emphasss has been placed on the biochemical changes associated with the disease - particularly changes in the lipid and lipoprotein composition of the blood. Studies of the structure of the arterial wall and of the structural changes occurring during the development of atherosclerotic lesions have been relatively neglected. Atherosclerosis is, however, a focal disease. In studying the pathogenesis of the lesions, and in attempting to account tor their localization, one must consider not only the composition and pressure of the fluid bathing and passing into the arterial wall, but also, obviously, the structure of the wall itself.

Improved therapies for high grade gliomas (HGG) are urgently needed, as the median survival for grade IV gliomas is just 15 months after treatment with surgery, chemotherapy and radiation. Recently, bone morphogenetic protein (BMP) signaling has been shown to play a tumor suppressing role on the glioma stem cell (GSC) population. However, the effects of BMP signaling on the differentiated population comprising the bulk of the tumor remains incompletely understood. In addition, studies examining the expression of BMP signaling molecules in HGG have shown contrasting results. To further our knowledge of the role of BMP signaling in HGG we used a combination of genetic analyses and a novel murine model of HGG to generate transformed astrocytes with oncogenic Kras, deletion of p53 and deletion of Bmpr1a. As a result of our studies, we have shown that BMP signaling is not largely altered or lost in human Glioblastomas. In addition we found that BMP signaling is present and active in the majority of HGG cells, indicating that BMP signaling is active in the differentiated, astrocytic tumor cells. Finally, using transformed murine and human oncogenic astrocytes, we determined that BMP signaling is tumor promoting in differentiated tumor cells through increased proliferation, invasion and migration. Our results indicate that BMP signaling is context dependent in HGG and as a result we suggest BMP inhibition as a novel therapeutic agent in the treatment of both adult and pediatric HGG.

Thesis (Ph. D.)--Boston University / Hemorrhagic disorders designated by the term "purpura" are usually associated with the appearance of petechiae, ecchymoses, and lowered platelet counts. However, the mechanism of bleeding and the etiology remain unsolved. The cheek pouch of the hamster was used in an attempt to determine the cause of the bleeding under two conditions: first, in experimental purpura produced by antiplatelet serum prepared by repeated injections of hamster platelets into rabbits, and second, following infusion with dextran. Peripheral blood counts, bone marrow examinations, coagulation tests, and special tests for vascular fragility and hemostatic function (negative pressure, snake venom, and microelectrode) have been applied to normal hamsters as a basis for interpretation in hemorrhagic diathesis. Microscopic observations were made in vivo and recorded on Kodachrome motion picture film by means of cinephotomicrographic equipment. The results of previous blood counts and bone marrow examinations have been confirmed and analyzed more critically. Detailed observations have been made on the morphology of the blood cells in the stained smear and reticulocyte counts have been reported for the first time in the hamster. The red cell count in the hamster (6.8 ± 1.2 million per cu. mm.) is slightly higher than that in man, and the reticulocyte value is also higher (2.5 ± 1.2 per cent). The polymorphonuclear and lymphocytic values were reversed in the hamster (polymorphs 30 ± 6 per cent, lymphocytes 61 ± 7.5 per cent). The peripheral blood smear showed moderate polychromatophilia and occasional target cells. The bone marrow of the hamster was more cellular than that of man, with a ratio of white cells to red cells of 8:1. The coagulation tests were within limits comparable with those for man. Three in vivo tests for vascular fragility and hemostatic function in the hamster cheek pouch were utilized: namely, the moccasin venom test (Fulton, Lutz, Shulman, and Arendt, in press); the negative pressure test (Shulman, Mode, Kagan, and Fulton, Anat. Rec. 118:408, 1954); and the microelectrode test (Fulton, Akers, and Lutz. Blood 8:140, 1953). The snake venom test applied to the cheek pouch of the normal hamster produced 71 ± 6 petechiae at one hour intervals and 138 ± 20 at the end of two hours. The negative pressure test produced from 0 to 4 petechiae at one minute Nith a negative pressure of 20 mm of mercury. The microelectrode test was used to evaluate the fragility of blood vessels by stimulation of the wall with single faradic shocks. Vasoconstriction occurred at low voltages (threshold, 4 to 10 volt single shock) in muscular arterioles and venules. The sphincters were more sensitive than other portions of the vascular network. White cell sticking and platelet thrombosis occurred at higher voltages (10 to 3O volts). The vessel wall of normal hamsters was resistant even to very high voltages (150 volts). If normal vessels were ruptured, the broken ends were sealed immediately, probably by "electrocoagulation". The results of the microelectrode test were compared in young and "old age" hamsters. No significant differences were obtained except for an increase in white cell adhesiveness in the "old age" group. Hamsters of either sex and 75 to 100 grams in weight were splenectomized. The platelet counts increased daily for 4 to 6 days after splenectomy and gradually returned to normal on the 14th to 18th day. The smear of peripheral blood exhibited increased polychromatophilia, target cells, and clumps of platelets, particularly on the 4th to 8th day. Howell-Jolly bodies were absent. Changes in the bone marrow were not remarkable. The microelectrode test for thrombus susceptibility revealed a marked tendency for thrombosis, while the fragility threshold did not differ from that in normal hamsters. Experimental thrombocytopenic purpura in hamsters, caused by injection of antiplatelet serum, produced spontaneous purpura, ecchymoses and bleeding manifestations in the cheek pouch and in almost all organs of the body. The platelet counts were decreased and the bone marrow showed immature-like amorphic megakaryocytes. Bleeding times and clot retraction determinations were abnormal. Values for the bleeding time in excess of 240 seconds v-rere not uncommon (normal bleading time, 109 ± 19). The snake venom test produced profuse numbers of petechiae within one half hour. Stimulation of the blood vessel wall with low voltage produced platelet thrombi in normal hamsters. In thrombocytopenic hamsters, thrombus formation and leukocytic sticking did not occur even with high voltages. However, the vessel walls were fragile and rupture occurred at electric thresholds lower than 150 volts (60 to 140). These changes were more marked at 24 hours after treatment with antiplatelet serum than at two hours. Small repeated injections of antiplatelet serum produced similar results. In control experiments, hamsters were injected with serum obtained from normal rabbits and with saline solution. The test procedures showed no appreciable deviations from normal values. The fragility thresholds were normal. The splenectomized hamsters with elevated platelet counts were given antipletelet serum. The fragility threshold to electrical stimulation of the vessel wall was lowered and hemorrhage occurred at low voltages. Consequently, splenectomy and the concomitant increase in numbers of circulating platelets shed no protective effect in experimental purpura. Recently, detrimental reactions to plasma substitutes have been critically evaluated and the dextrans have been reported to cause a hemostatic defect in human beings. Dextran increased the bleeding time in normal volunteers as well as in patients with shock. The exact nature of the bleeding phenomenon has not been determined. The precise techniques available for the study of hemorrhage in the hamster cheek pouch have been used to evaluate the hemostatic defect caused by dextran and to observe in vivo the changes occurring in the formed elements of the blood end in the characteristics of the vessel wall. Hematological changes in the hamster after infusion with dextran were insignificant except for the effects of hemodilution and the clumping of platelets. The results of the various coagulation tests (clotting time, prothrombin time, clot retraction, and fibrinolysis test) were within normallimits. The bleeding time was prolonged significantly as shown by values of more than 240 seconds as compared with values of 109 ± 19 seconds in normal hamsters. All dextrans used in this study (Lares, Cutter) produced an increased bleeding time except Expandex. The Lares dextran seemed to be more detrimental than other types. After injection of Lares, increased numbers of leukocytes were adherent to the endothelium at 24 hours and during a period of 3 to 4 weeks. The thrombosis threshold was increased. The formation, canalization, and embolization of thrombi were recorded on Kodachrome motion picture film. The frag ility threshold, as tested with microelectrode and also snake venom, was lowered. The vascular defect was greater with Lares than with other dextrans. In conclusion, experimental purpura was produced in hamsters by antiplatelet serwn for the first time. The resultant bleeding phenomenon and hemostatic defect was related to lowered platelet counts and decreased frag ility of the vessel wall. Splenectomy accompanied by increased platelet counts was not remedial. The effects of dextran infusions in hamsters have been critically evaluated by routine hematological tests and by special tests for vascular fragility and hemostatic function. A defect in the vessel wall was shown by the lowered fragility to faradic stimulation. This finding provided the basis for a new explanation for the hemostatic defect, namely, damage to the vessel wall. This is in addition to the previously known factors of prolonged bleeding time and unexplained clumping of the platelets.

Alzheimer’s disease (AD) is a chronic neurodegenerative disease with a multitude of contributing genetic factors. The apolipoprotein E (APOE) allele e4 imparts a dramatic increase in the risk of developing Alzheimer’s disease, but the exact mechanism of this relationship is unknown. The e4 allele is associated with increased Ab plaques, neurofibrillary tangles, and a heightened inflammation state, all pathological hallmarks of Alzheimer’s disease. To test the hypothesis that microglia and related cytokines were differentially associated with Alzheimer’s disease pathology based on the presence of e4, we compared individuals with and without the APOE e4 allele within a community based aging cohort (n = 186). Cellular density of Iba1, a marker of microglia, was positively associated with tau pathology as measured by AT8 immunostaining (B = 0.459, p = 0.028) in e4 positive participants but not in e4 negative participants. Analysis of cytokines implicated in AD, i.e. IL-10, IL-13, IL-4, IL-1a, revealed a significant negative association with AT8 in e4 negative participants. The association of the anti-inflammatory cytokines IL-10, IL-13, and IL-4 on tau pathology appeared to be mediated by ApoE protein levels, suggesting that these cytokines and the ApoE protein may interact to prevent increased tau pathology within e4 negative individuals. The pro-inflammatory cytokine, IL-1, was negatively associated with AT8 (B = -0.241, p = 0.009) independent of Ab1-42 in e4 negative participants but not in e4 positive participants, suggesting a potential novel protective association. Overall, in e4 negative participants, elevated levels of IL-10, IL-13, IL-4, IL-1a are associated with less tau pathology. These associations are largely absent in the presence of e4 where tau pathology is significantly associated with microglial cell density. Taken together, these results suggest that APOE e4 mediates an altered inflammatory response and increased tau pathology independent of Ab pathology. / 2019-07-03T00:00:00Z

The family of ribosomal S6 Ser/Thr protein kinases (RSK) controls proliferation, viability and motility and, therefore, contributes to the etiology of numerous cancers, including breast. We found that RSK2 is an obligate partner in estrogen receptor alpha (ER)-driven breast cancer by physically interacting with ER to activate a pro-neoplastic transcriptional network. ER sequesters RSK2 in the nucleus and ER+ tumor growth is dependent on nuclear RSK2. In a novel mouse model, mammary-specific expression of nuclear RSK2 drives development of high grade ER+ ductal carcinoma in situ. Besides being a driver in breast cancer, ER+ cells are indispensable for normal mammary gland function. Therefore, we investigated RSK2 contributions to mammary gland homeostasis. We discovered that activation of extracellular signalâregulated kinase 1/2 (ERK1/2) and subsequently RSK2 are necessary for maintenance of ERï¡ levels in the presence of estrogen. This protective mechanism is a part of a negative feedback loop, as estrogen positively regulates expression of growth factors that activate ERK1/2-RSK2 signaling. As ER degradation is intimately linked with its transcriptional activity, loss of RSK2 alters the transcriptome architecture in response to estrogen. Consequently, inappropriate hormonal responses cause increased DNA damage. Together, our findings indicate that RSK2 regulates ER-mediated processes in both breast cancer and in normal mammary epithelium. In addition to ER+ breast cancer, RSK contributes to triple negative breast cancer (TNBC). Levels of active RSK are increased in ~70% of TNBCs and RSK regulates migration in TNBC. As TNBC patients have increased probability of death due to metastasis, we described an in vivo study showing the efficacy of RSK-targeting in metastatic TNBC. We found that RSK1 and RSK2 regulate metastatic colonization and growth suggesting that targeting RSK is a potential therapeutic strategy for metastatic breast cancer. Development of targeted therapies for breast cancer is frequently hindered by the lack of in vitro models that recapitulate diverse tumor phenotypes. As tumor heterogeneity contributes to chemotherapy resistance and decreased patient survival, we developed an organoid culture system that recapitulates tumor heterogeneity. Our methodology focuses on quantifiable cellular phenotypes and provides a novel tool for drug-testing.

The endometrium is the tissue lining the inner cavity of the uterus in which nidation and pregnancy maintenance occurs. To date, there are no physiological models that recapitulate the human endometrial microenvironment; thus, our understanding of the role of the vasculature in regulating endometrial reproductive processes remains largely unknown. âOrgans-on-a-Chipâ (OoC) models are compartmentalized microfluidic cultures of heterotypic cells that better approximate the human in vivo conditions. Herein, we engineered and established an OoC model of the human endometrial perivascular stroma to test the hypothesis that the endometrial vascular endothelium plays a role in regulating both normal reproduction function and disease pathogenesis. We examined the crosstalk between prolonged cultures of human endometrial endothelial cells and stromal fibroblasts under hormonal and physiological signals. Our studies demonstrated that shear stress-induced secretion of specific endothelial cell-derived prostaglandins enhances perivascular response to progesterone via a paracrine mechanism. Altogether, these translational findings show that the endometrial vascular endothelium plays a key physiologic role during the initiation of perivascular decidualization in the human endometrium. Furthermore, vascular dysfunction alters the immune-endocrine inflammatory axis of the endometrium and contributes to the pathogenesis of endometrial disorders. Specifically, endocrine disruptors such as the environmental toxicant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) promoted an enhanced immune cell recruitment. Identification of specific inflammatory mediators necessary during endometrial reproductive processes may have clinical utility as therapeutic targets for reproductive disorders such as infertility, endometriosis, preeclampsia and poor pregnancy outcomes.

The delay that occurs between specimen acquisition and analysis in clinical and forensic toxicology requires the establishment that no changes in drug concentration have occurred during this timed interval. In this research, severai groups of common drugs were examined for stability in serum, blood and tissues at room temperature and at 4°C. Specifically, benzodiazepines, barbiturates, lidocaine, procainamide and nortriptyline were studied. Decreases were found in the following drugs: chlordiazepoxide, norchlordiazepoxide, demoxepam, and nitrazepam. No changes were found in the other drugs. More detailed work was performed on chlordiazepoxide (CDP). Two breakdown products, demoxepam and nordiazepam (ND) were identified and quantitated. A series of experiments at various pH's in the presence and absence of fluoride/oxalate (F-/C2O2=) were undertaken to examine chemical and microorganism effects on CDP breakdown in blood and buffer. At pH5, the rate of CDP breakdown was the same in blood and buffer and no nordiazepam was formed in either medium. This was determined by comparing the slopes of ln(CDP) vs. time for each condition; the slopes were about -.06 for each. All slopes are in (days)-1. At pH 6.5 and pH 8, in the absence of F-/C2O2=, CDP was less stable in blood than buffer (slopes of -.13 and -.27 versus -.036 and -.039) and ND was formed in the blood. At these pH's, F-/C2O2= stabilized CDP in blood such that it was more stable than buffer (slopes of -.0047 and -.0066 versus -.038 and -.036).

It has been reported in previous works that there is a greater neuron density in the stellate ganglion of patients with cardiovascular disease. However, an analysis of this effect on neuron density and how it may differ between the different conditions falling under the realm of cardiovascular disease has yet to be studied. Analysis of this relationship between the Autonomic Nervous System (ANS) and cardiovascular function can provide insight into the disease process of each of the studied conditions, and more specifically, whether the ANS plays more of a causative or compensatory role in these instances. In this study, stellate ganglion pathology from patients with Coronary Artery Disease (CAD), Myocardial Infarction (MI), or Heart Failure (HF) were studied and compared to subjects with little to no cardiovascular pathology. We hypothesized that cardiovascular disease patients would have higher levels of neural remodeling, and perhaps more so in chronic conditions like CAD and HF as opposed to single events like MI. Stellate ganglia were harvested from one or both sides of 17 human cadavers and prepared slides from the middle section of each ganglion were scanned digitally for analysis. Neurons were counted using an automated algorithm accounting for size and shape to specifically select for nerve cell bodies, and for further analysis, heat maps of neuron nearest neighbor density were created. Analysis considering the variables of neuron size, number of neurons, and percent area of the ganglion occupied by neurons resulted in a statistical main effect of disease cohort but not side of the ganglion or the interaction of cohort and side. Between subject effects showed that only average neuron size was a significant factor in the model. Overall, patients with cardiovascular disease displayed neural remodeling in comparison to those with little to no cardiovascular pathology, and these effects were different across the several different conditions. Some caveats to this study were sample size, especially for MI patients, and analysis of only the middle section of each ganglion. A further analysis including more of the ganglion outside of a representative section, and more subjects in each cohort, especially with MI pathology, shows promise of more definitive conclusions.

Intimal hyperplasia occurs as a response to a variety of vascular insults and results in vascular stenosis, and organ ischemia. This process represents a fundamental component of atherosclerosis, venous graft stenonsis, and allograft arteriopathy in solid organ transplants. Smooth muscle cells (SMCs), and their associated extracellular matrix (ECM) form major components of intimal hyperplasia. We hypothesize that chemokines play a critical role in SMC migration into such intimal lesions. A number of chemokine-chemokine receptor interactions that mediate inflammatory cell recruitment have been characterized. However, the specific chemokine- chemokine receptor pathways that contribute to SMC recruitment are not known. The aims of this study are to examine the expression of C-C chemokine receptor 1 (CCR1) on medial SMCs (MSMCs), and to test its functionality in SMC recruitment. SMCs were derived from murine aortas; cultures were >95% SMC as demonstrated by the expression of smooth muscle α-actin (SMA), calponin, smooth muscle myosin heavy chain (SM-MHC). Interferon-gamma (IFN-γ) and Tumor necrosis factor- alpha (TNF-α) - stimulated MSMCs express CCR1 with a peak expression between 30 h and 48 h after cytokine stimulation. The functionality of receptors was initially demonstrated by agonist-induced calcium mobilization: the addition of CCR1 ligands, Regulated on activation, Normal T cell expressed and secreted (RANTES) and Macrophage inflammatory protein -1α (MIP-1α) to MSMCs caused an increase in intracellular Ca2+ concentration. Blockade of CCR1 by BX471, a CCR1 antagonist, inhibited the Ca2+ mobilization induced by RANTES and MIP-1α. The results suggest that up-regulation of CCR1 expression on cytokine-stimulated SMCs may facilitate recruitment into intimal lesions through endothelial-derived chemokine expression.