Pathobiological Response Research Articles

Changes of tumor infiltrating lymphocyte subtypes before and after neoadjuvant endocrine therapy in estrogen receptor-positive breast cancer patients – an immunohistochemical study of cd8+ and foxp3+ using double immunostaining with correlation to the pathobiological response of the patients

Tumor-stromal interactions involve continuous crosstalk and interactions among different cell types and play pivotal roles in tumorigenesis, tumor development, disease progression, subsequent metastasis, and also tumor response to therapeutic agents. Tumor infiltrating lymphocytes (TILs) are important components of these tumor-stromal interactions. Specific TIL subtypes are known to be involved in the clinical course of individual patients. However, the status of TILs following endocrine therapy has not been studied in breast cancer patients. We evaluated the alterations of TIL subtypes in a cohort of East Asian patients with estrogen receptor-positive breast cancer during the course of neoadjuvant steroidal aromatase inhibitor (AI) therapy, using double immunohistochemical staining of CD8+ and T regulatory cells (Treg) or Foxp3+, yielding the CD8+/Treg ratio in individual patients. Changes in CD8+/Treg ratio before and after therapy were then correlated with pathobiological responses of individual patients based upon alterations of the Ki-67 labeling index (LI). A significant increase in the CD8+/Treg ratio was detected in responders (p=0.028) but not in non-responders, which may reflect the dynamic process in which the host immune response to tumor antigens changed in consequence of an interaction between tumor and stromal cells in its microenvironment following estrogen depletion caused by the AI. The CD8+/Treg ratio in breast cancer tissue can be a potential surrogate marker in surgical pathology specimens for predicting responses to neoadjuvant endocrine therapy, not only incorporating features of carcinoma cells as in Ki-67 LI but also those of adjacent stromal cells in the tumor microenvironment, especially in the early stage of treatment prior to any detectable clinical and/or histopathological changes.

P-024 Stress distribution after intracranial stent by realistic model

There is no effective treatment for symptomatic intracranial atherosclerotic stenosis, which has an association with a high rate of recurrent stroke. Percutaneous transluminal angioplasty and stenting (PTAS) has been applied...

Effects of estrogen depletion on angiogenesis in estrogen-receptor-positive breast carcinoma – an immunohistochemical study of vasohibin-1 and CD31 with correlation to pathobiological response of the patients in neoadjuvant aromatase inhibitor therapy

Objectives: Tumor–stroma interactions, including angiogenesis, are pivotal in breast cancer. Changes of angiogenesis during endocrine therapy have not been reported in breast cancer patients. Vasohibin-1 (VASH-1) is a recently identified endothelium-derived negative feedback regulator of angiogenesis. Vasohibin-1 positive ratio (VPR) is proposed as an indicator of neovascularization of the tissues.Methods: The status of neovascularization, based on VPR before and after steroidal aromatase inhibitor (AI) exemestane (EXE) treatment, was evaluated in 54 post-menopausal Asian patients. VPR changes were correlated with the pathobiological response of the patients using Ki67 labeling index (LI) changes.Results: When using a decrement of more than 40% in post-treatment Ki67 LI as the definition of response, significant inverse correlation was detected between Ki67 LI and VPR changes in responders. Significant increment in neovascularization, as demonstrated by elevated VPR, was only detected in responders (p = 0.039). Increased angiogenesis detected in responders to neoadjuvant therapy may represent a stromal response to dying/dead cells, as part of tumor–stroma interaction following estrogen depletion.Conclusions: VPR could be a potential surrogate marker for predicting neoadjuvant endocrine therapy response, incorporating features of both carcinoma and stromal cells, in the early stage of neoadjuvant endocrine therapy before any discernible clinical and/or histopathological changes became apparent.

Increased artery wall stress post-stenting leads to greater intimal thickening

Since the first human procedure in the late 1980s, vascular stent implantation has been accepted as a standard form of treatment of atherosclerosis. Despite their tremendous success, these medical devices are not without their problems, as excessive neointimal hyperplasia can result in the formation of a new blockage (restenosis). Clinical data suggest that stent design is a key factor in the development of restenosis. Additionally, computational studies indicate that the biomechanical environment is strongly dependent on the geometrical configuration of the stent, and, therefore, possibly involved in the development of restenosis. We hypothesize that stents that induce higher stresses on the artery wall lead to a more aggressive pathobiologic response, as determined by the amount of neointimal hyperplasia. The aim of this investigation was to examine the role of solid biomechanics in the development of restenosis. A combination of computational modeling techniques and in vivo analysis were employed to investigate the pathobiologic response to two stent designs that impose greater or lesser levels of stress on the artery wall. Stent designs were implanted in a porcine model (pigs) for approximately 28 days and novel integrative pathology techniques (quantitative micro-computed tomography, histomorphometry) were utilized to quantify the pathobiologic response. Concomitantly, computational methods were used to quantify the mechanical loads that the two stents place on the artery. Results reveal a strong correlation between the computed stress values induced on the artery wall and the pathobiologic response; the stent that subjected the artery to the higher stresses had significantly more neointimal thickening at stent struts (high-stress stent: 0.197±0.020 mm vs low-stress stent: 0.071±0.016 mm). Therefore, we conclude that the pathobiologic differences are a direct result of the solid biomechanical environment, confirming the hypothesis that stents that impose higher wall stresses will provoke a more aggressive pathobiological response.

Leukaemia inhibitory factor is over‐expressed by ischaemic brain tissue concomitant with reduced plasma expression following acute stroke

Leukaemia inhibitory factor (LIF) is a glycoprotein of the interleukin-6 family, which has potent pro-inflammatory properties and is involved in regulation of neuronal differentiation. We have previously identified its upregulation in gene microarrays following acute ischaemic stroke in man. LIF expression and localization was measured in human ischaemic stroke autopsy specimens, in a rat model of middle cerebral artery occlusion (MCAO) and in human foetal neural cell cultures following oxygen-glucose deprivation (OGD) by Western blotting and immunohistochemistry. Circulating LIF was determined in the plasma of patients in the hyper-acute stroke phase using a multiplex enzyme-linked-immunosorbent serologic assay system. Patients demonstrated an increase in LIF expression in peri-infarcted regions with localization in neurons and endothelial cells of microvessels surrounding the infarcted core. The rat MCAO model showed similar upregulation in neurons with a peak increase at 90 min. Circulating serum LIF expression was significantly decreased in the hyper-acute phase of stroke. Brain-derived neurons and glia cultured in vitro demonstrated an increase in gene/protein and protein expression respectively following exposure to OGD. Increased LIF expression in peri-infarcted regions and sequestration from the peripheral circulation in acute stroke patients are characteristic of the pathobiological response to ischaemia and tissue damage.

Acute Pancreatitis: Bench to the Bedside

Acute Pancreatitis: Bench to the Bedside

Characterization of cell motility in single heart valve interstitial cells in vitro.

Valve interstitial cells (VIC) are the most prevalent cells in the heart valve, regulating to a large extent the normal biology of the valve and its pathobiological response to disease. In the process of valve tissue repair by VICs, single cell motility is likely to be important, as it is in wound repair by most mesenchymal type cells. We designed in vitro experiments using low density monolayer cultures to study the association of morphology and motility in single VICs which expressed alpha-smooth muscle actin. We observed that the morphology of single VICs can be categorized into six types which are reminiscent of the shape of VICs seen in vivo during valve repair. Of these morphologies, round, rhomboid, tailed and spindled shaped VICs were the most common. VICs did change their morphology over time. Rhomboid cells could become tailed or spindle-shaped and vice versa. Using time-lapse imaging and immunofluorescent microscopy, we showed that VIC morphologies reflect differences in cell motility and cell-matrix interactions. Tailed and spindle-shaped VICs were the predominant motile types and were associated with few extracellular fibronectin fibrils and less focal adhesions, as demonstrated by vinculin staining. Round and rhomboid shaped VICs were less motile and were associated with prominent vinculin and extracellular fibronectin fibrils. We found that cell mitosis is an important determinant of VIC migration. Many of the motile VICs were associated with mitosis as the daughter cells separated by migrating as tailed and spindle shaped cells. Thus cell morphology is an important determinant of VIC motility.

Acute pancreatitis

This review presents advances in our understanding of the pathobiologic responses of acute pancreatitis from studies using animal models of experimental pancreatitis as well as results of key clinical trials and observations. The reports during the past year show significant advances in our understanding of the pathobiology of acute pancreatitis. In particular, there are findings presented that are relevant to our further understanding of pancreatic intracellular digestive enzyme activation; the pancreatic inflammatory response; and cell death responses such as necrosis as apoptosis. Other reports add to understanding of the control of microcirculatory disturbances in acute pancreatitis, and of the role of the pancreatic neural system in regulating the microcirculation as well as the pain associated with the disorder. Finally, there are clinical trials showing benefits of enteral feeding on outcome of acute pancreatitis as well as the finding that diclofenac prevents endoscopic retrograde cholangiopancreatography-induced pancreatitis. Our understanding of the mechanistic processes that mediate the pathobiologic responses of pancreatitis is rapidly evolving. In addition, we now have initial evidence for potential treatment strategies for this disorder. Testing treatment strategies will lead to improved therapies and outcomes for patients with acute pancreatitis.

Acute pancreatitis

This review presents advances in our understanding of the pathobiologic responses that mediate acute pancreatitis with an emphasis on the interrelationship between the events occurring in the pancreatic acinar cell and the vascular, neural, and immune systems; information on recent reports describing clinical diagnostic and therapeutic aspects of autoimmune pancreatitis; and information on feeding strategies during acute pancreatitis. The reports during the past year provide important and clinically relevant findings about roles of intracellular events as well as vascular and neural regulatory pathways involved in the mechanism of pancreatitis. Reports during the past year also add to our rapidly growing portfolio describing the characteristics, course, and therapeutic responses in autoimmune pancreatitis. Finally, a provocative report demonstrates that a low-fat elemental-like diet administered by nasogastric tube during severe pancreatitis does not worsen outcome compared with administration of the diet by nasojejunal tube. This report provides rationale for early feeding in these patients by a simpler route than previously recommended and also raises the question about the types of nutrients that should be used in this situation that have the least effect on neurohumoral stimulation of the pancreas. Our understanding of the mechanistic processes that mediate the pathobiologic responses of pancreatitis is rapidly evolving. The continuing challenge is to translate these findings into treatment strategies for pancreatitis.

Clinical, Hematological, and Biochemical Analysis of Experimental Endotoxemia in Thoroughbred Horses

To evaluate the biological response of the horse to endotoxemia, a sublethal amount of lipopolysaccharide (LPS) (10 μg/kg) was given to two Thoroughbreds in two doses 24 hr apart. Each infusion initially produced a significant increase or decrease in rectal temperature, an increase in respiratory rate and heart rate, and a marked decrease in white blood cell count (WBC). The horses subsequently showed signs of shock, characterized by extreme coldness of the skin of lower limbs, as well as cyanosis of the visible mucosae, oliguria accompanied by proteinuria, and abnormalities in gastrointestinal function. The clinical signs of equine endotoxemia may be manifested by the clinical condition of the systemic inflammatory response syndrome (SIRS): two or more of the above signs, such as high or low rectal temperature, increased heart rate and respiratory rate, and leukopenia. Pathobiological responses such as a severe decrease in the number of platelets, hypoglycemia, metabolic acidosis, disorders of hemostasis accompanied by cyanosis of the visible mucosal membranes, proteinuria and oliguria, and abnormal gastrointestinal function, may be manifestations of pathobiological conditions ranging from disseminated intravascular coagulation (DIC) to multiple organ dysfunction syndrome (MODS). Therefore, the clinicopathological responses in equine endotoxemia suggest the nature of SIRS elicited by hypercytokinemia progressing into septic shock.

Glomerulopathic Light Chain-Mesangial Cell Interactions Modulate in Vitro Extracellular Matrix Remodeling and Reproduce Mesangiopathic Findings Documented in Vivo

Glomerulopathic light chains (LCs) are associated with two distinct mesangiopathies: AL (light-chain-related) amyloidosis and light-chain deposition disease (LCDD) with immunomorphologic features that are well documented in the literature. Even though both conditions are caused by monoclonal LCs, these entities differ dramatically in their morphologic expressions. In AL amyloidosis the mesangial matrix is replaced by amyloid fibrils, while in LCDD the matrix increases as a consequence of deposition of excess extracellular matrix (ECM). The immunomorphologic mesangial alterations observed in biopsy material are closely reproduced in vitro when mesangial cells grown on an artificial matrix are incubated with monoclonal light chains obtained from the urine of patients with either condition. This article summarizes previously reported data, reports new findings, and focuses on integrating all the available information on the subject. When mesangial cells are incubated with LCDD-LCs, production of ECM proteins (collagen IV, laminin, fibronectin, and tenascin) is increased, with maximum effect at 72 hours post LC treatment. A concomitant decrease in collagenase IV activity further accentuates the accumulation of mesangial matrix. These effects are mediated through transforming growth factor-beta (TGF-beta) activation. In contrast, when mesangial cells are incubated with Am-LCs, a decrease in ECM protein production and a stimulatory effect on collagenase IV is observed, which results in matrix degradation and facilitates amyloid deposition. The decreased TGF-beta documented in the literature in this setting precludes adequate matrix repair. These findings substantiate the morphologic alterations observed in renal biopsy specimens and in the in vitro model. Using this in vitro model, it is then possible to delineate the LC interactions with putative receptors at the mesangial cell surface that regulate mesangial cell pathobiologic responses and mesangial matrix homeostasis.

Compensatory arterial enlargement is a common pathobiologic response in early atherosclerosis

Background: Human arteries are dynamic conduits that respond to different stimuli by remodeling their structure and size. Arterial dilatation has been shown to occur in moderate and advanced atherosclerosis in studies that evaluated only one artery, either coronary, carotid, or superficial femoral artery (SFA). The purpose of this study was to quantify and compare compensatory arterial enlargement throughout the peripheral vascular system in early atherosclerosis. Methods: Seventy-two patients (40 male, 32 female, mean age 67 ± 12 years) underwent transcutaneous B-mode ultrasound imaging during routine examinations. Thirty-nine carotid, 19 aorta, 19 iliac, 23 common femoral (CFA), 21 SFA, and 23 popliteal arteries were longitudinally imaged. Eight healthy volunteers (6 male, 2 female, mean age 27 ± 2.2 years) had the same arteries evaluated (n = 48). Internal diameter (ID) and external diameter (ED) were measured in disease-free areas and in paired adjacent areas exhibiting increased intima-media thickening (IMT) and small atherosclerotic plaques. The percent change in ID, ED, IMT, and plaque thickness were calculated. Results: There was no observed change in ID or ED in all arteries of the healthy volunteers. When compared with normal vessel segments, all arteries demonstrated a marked decrease in ID and increase in ED in areas of small, hemodynamically insignificant plaque. The aorta had a 6.00% ± 1.92% increase in ED, which was significantly less than the percent increase in ED observed in carotid (8.14 ± 4.5%. P = 0.05), CFA (9.73 ± 3.54%, P = 0.0001), SFA (9.15 ± 4.25%, P = 0.005), and popliteal arteries (9.67 ± 4.34, P = 0.002). In all arteries there was a strong correlation between plaque thickness and percent change in ED with the best correlation observed in the popliteal artery (R 2 = 0.823, P <0.0001). IMT was significantly increased in all normal vessel segments of the patients when compared with the healthy volunteers ( P <0.001). Conclusion: All peripheral arteries dilate in response to intima-media thickening and early atherosclerotic plaque formation. This adaptive response occurs at the site of the lesion to preserve luminal area. The percent change in ED is strongly related to plaque thickness and is greatest in the more distal arteries.

Pathobiologic Responses to Stenting

As the interventions available to treat obstructive coronary artery disease become increasingly complex, our understanding of the vascular response to these interventions requires greater sophistication. Molecular and cellular biologic tools have now propelled us into another phase of work with vascular devices. Initially, studies of endovascular implants such as stents focused on developing models of vascular injury. With these models, we could then examine the designs of individual stents and connect structure with performance. Now we are entering a third phase in which stent manufacturers are looking to science to dictate stent design.

Carbohydrate Recognition by Mycoplasma pneumoniae and Pathologic Consequences

Mycoplasma pneumoniae infection in the human is often followed by a transient autoimmune hemolytic disorder characterized by high titer autoantibodies to a carbohydrate antigen, the I antigen. Because the major host cell receptor for the Mycoplasma is the sialylated form of this antigen, it is likely that the immunologic disorder is initiated by the microbe-saccharide interaction. Here we review briefly knowledge on the autoantibodies and the structures and distribution of the saccharide antigens and receptors. We discuss possible mechanisms for the triggering of autoantibody production and consider ways in which perturbation of various glycoprotein carriers of the carbohydrate ligands may elicit a variety of pathobiologic responses. We conclude by highlighting ideas on further molecular dissections of the elements of the microbe-host interaction.

Pulmonary and Pleural Responses in Fischer 344 Rats Following Short-Term Inhalation of a Synthetic Vitreous Fiber: II. Pathobiologic Responses

The pleura is a target site for toxic effects induced by a variety of fibrous particulates, including both natural mineral and man-made vitreous fibers. We examined selected cytological and biochemical indicators of inflammation in both the pleural compartment and pulmonary parenchyma in F344 rats following inhalation of RCF-1, a kaolin-based ceramic fiber. Male F344 rats were exposed by inhalation to 89 mg/m3(2645 WHO fibers/cc) RCF-1 6 hr/day for 5 consecutive days. In lung parenchyma, cytological and biochemical inflammatory responses occurred rapidly following exposure. In contrast, pleural responses were delayed in onset and of a much smaller magnitude than those observed in lung. At both Day 1 and Day 28 postexposure, increased quantities of lactate dehydrogenase,N-acetyl glucosaminidase, alkaline phosphatase, albumin, and neutrophils were present in bronchoalveolar lavage fluid. These responses were attenuated at the latter time point. No significant responses were detected in pleural lavage fluid until 28 days following exposure, at which time elevated numbers of macrophages and eosinophils, but not neutrophils, were observed. Increased albumin and fibronectin were also observed in PLF at this latter time point. These findings demonstrate that the onset of pleural and pulmonary responses following inhalation of RCF-1 are temporally separated and that pleural injury may increase in severity with time following exposure. The increase in severity of pleural inflammation found in the postexposure period cannot be readily explained by fiber translocation.

Comparative Effects of Chronic Ethanol Consumption on the Properties of Mitochondria from Rat Brain and Liver

The effects of chronic alcohol consumption on biochemical properties of mitochondria isolated from liver and brain were compared in rats. As has been found in previous studies (reviewed in Thayer WS: Ann NY Acad Sci 492: 193-206, 1987) in liver, ethanol consumption led to a 41% decrease in active phosphorylating (state 3) respiration and a 25% decrease in resting (state 4) respiration. These changes resulted in a 23% decrease in the respiratory control ratio (ratio of respiration rate in state 3 to that in state 4). These effects were associated with a 40% decrease in functional cytochrome oxidase content, determined spectrophotometrically as heme aa3. By contrast, in brain mitochondria isolated from the same rats, ethanol consumption did not result in any significant changes in respiration rates, respiratory control ratio, or cytochrome contents. The findings demonstrate a differential pathobiologic response of brain and liver mitochondria to chronic ethanol consumption. Since the liver is predominant in metabolism of ingested ethanol, the findings of this study suggest that the deleterious effects of chronic alcohol consumption on the structure and function of liver mitochondria may be related to ethanol metabolism.