Smooth Muscle Hyperplasia due to ACTA2/MYH11 Mutations: Identification of Novel Pathology and Pathways Leading to Aneurysms and Diverse Vascular Occlusive Diseases

Missense mutations in smooth muscle cell (SMC) specific ACTA2 (á-actin) and MYH11 (â-myosin heavy chain) cause diffuse and diverse vascular diseases, including thoracic aortic aneurysms and dissections (TAAD) and early onset coronary artery disease and stroke. The mechanism by which these mutations lead to dilatation of some arteries but occlusion of others is unknown. We hypothesized that the mutations act through two distinct mechanisms to cause varied vascular diseases: a loss of function, leading to decreased SMC contraction and aneurysms, and a gain of function, leading to increased SMC proliferation and occlusive disease. To test this hypothesis, ACTA2 mutant SMCs and myofibroblasts were assessed and found to not form á-actin filaments whereas control cells did, suggesting a dominant negative effect of ACTA2 mutations on filament formation. A loss of á-actin filaments would be predicted to cause decreased SMC contractility. Histological examination of vascular tissues from patients revealed SMC hyperplasia leading to arterial stenosis and occlusion, supporting a gain of function associated with the mutant gene. Furthermore, ACTA2 mutant SMCs and myofibroblasts proliferated more rapidly in static culture than control cells (p<0.05). We also determined that Acta2-/- mice have ascending aortic aneurysms. Histological examination revealed aortic medial SMC hyperplasia, but minimal features of medial degeneration. Acta2-/- SMCs proliferated more rapidly in culture than wildtype (p<0.05), and microarray analysis of Acta2-/- SMCs revealed increased expression of Actg2, 15 collagen genes, and multiple focal adhesion genes. Acta2-/- SMCs showed altered localization of vinculin and zyxin and increased phosphorylated focal adhesion kinase (FAK) in focal adhesions. A specific FAK inhibitor decreased Acta2-/- SMC proliferation to levels equal to wildtype SMCs (p<0.05), suggesting that FAK activation leads to the increased proliferation. We have described a unique pathology associated with ACTA2 and MYH11 mutations, as well as an aneurysm phenotype in Acta2-/- mice. Additionally, we identified a novel pathogenic pathway for vascular occlusive disease due to loss of SMC contractile filaments, alterations in focal adhesions, and activation of FAK signaling in SMCs with ACTA2 mutations.

Report on the practice based culminating experience as teaching assistant for "Pathology and Public Health" class taught at University of Texas School of Public Health, Houston

Objectives. The objectives of this report were to describe current best standards in online education, class competencies, class objectives, class activities and to compare the class competencies, objectives and activities undertaken with the current best practices in online teaching and to provide a list of recommendations based on the most efficacious practices. ^ Methods. Utilizing the key words- online teaching, national standards, quality, online courses, I: (1) conducted a search on Google to find the best standard for quality online courses; the search yielded National Standards for Quality Online Teaching as the gold standard in online course quality; (2) specified class objectives and competencies as well as major activities undertaken as a part of the class. Utilizing the Southern Regional Education Board evaluation checklist for online courses, I: (1) performed an analysis comparing the class activities, objectives, and competencies with the current best standards; (2) utilized the information obtained from the analysis and class experiences to develop recommendations for the most efficacious online teaching practices. ^ Results. The class met the criteria set by the Southern Regional Education Board for evaluating online classes completely in 75%, partially in 16% and did not meet the criteria in 9% cases. The majority of the parameters in which the class did not meet the standards (4 of 5) were due to technological reasons beyond the scope of the class instructor, teaching assistant and instructional design. ^ Discussion. Successful online teaching requires awareness of technology, good communication, methods, collaboration, reflection and flexibility. Creation of an online community, engaging online learners and utilizing different learning styles and assessment methods promote learning. My report proposes that online teaching should actively engage the students and teachers with multiple interactive strategies as evidenced from current best standards of online education and my “hands-on” work experience. ^ Conclusion. The report and the ideas presented are intended to create a foundation for efficacious practice on the online teaching platform. By following many of the efficacious online practices described in the report and adding from their own experiences, online instructors and teaching assistants can contribute to effective online learning. ^

Enlarged tracheoesophageal puncture: A systematic review and retrospective analysis

Background. An enlarged tracheoesophageal puncture (TEP) results in aspiration around the voice prosthesis (VP) and may lead to pneumonia. The aims of this research were: (1) to conduct a systematic review and meta-analysis on enlarged TEP; (2) to analyze preoperative, perioperative, and postoperative risk factors for enlarged TEP; and (3) to evaluate control of leakage around the VP using conservative treatments and adverse events in patients with enlarged TEP.^ Methods. A systematic review was conducted (1978-2008). A summary risk estimate was calculated using a random-effects meta-analysis model. A retrospective cohort study was completed. Patients who underwent total laryngectomy and TEP at The University of Texas M. D. Anderson Cancer Center (MDACC) were included. Multiple logistic regression methods were used to assess risk factors for enlargement. Descriptive and bivariate statistics were calculated to evaluate outcomes and adverse events. Results: Twenty-seven manuscripts were included in the systematic review. The summary risk estimate of enlarged TEP/leakage around the VP was 7.2% (95% CI: 4.8%-9.6%). Temporary VP removal and TEP-site injections were the most commonly reported treatments. Neither prosthetic diameter (p=0.076) nor timing of TEP (p=0.297) significantly increased risk of enlargement per stratified analyses of published outcomes. The cumulative incidence of enlarged TEP was 18.6% (36/194, 95% CI: 13.0%-24.1%) in the MDACC cohort. Enlarged TEP occurred exclusively in irradiated patients. Adjusting for length of follow-up and timing of TEP, advanced nodal disease (ORadjusted: 4.3, 95% CI: 1.0-19.1), stricture (ORadjusted : 3.2, 95% CI: 1.2-8.6), and locoregional recurrence/distant metastasis after laryngectomy (ORadjusted: 6.2, 95% CI: 2.3-16.4) increased risk of enlarged TEP. At last follow-up, conservative methods controlled leakage around the VP in 81% (29/36) of patients. Unresolved leakage was associated with recurrent cancer (p=0.081) and TEP-site irregularity (p=0.003). Relative to those without enlargement, enlarged TEP patients had significantly higher risk of pneumonia (RR: 3.4, 95% CI: 1.9-6.2).^ Conclusions. These data establish that enlarged TEP poses serious health risks, and provide insight into medical and oncologic factors that may contribute to development of this complication. In addition, this research supports the use of conservative treatments to address leakage after enlarged TEP in lieu of complete TEP closure.^

TB research at UT-Houston--a review of cord factor: new approaches to drugs, vaccines and the pathogenesis of tuberculosis.

Tuberculosis remains a major threat as drug resistance continues to increase. Pulmonary tuberculosis in adults is responsible for 80% of clinical cases and nearly 100% of transmission of infection. Unfortunately, since we have no animal models of adult type pulmonary tuberculosis, the most important type of disease remains largely out of reach of modern science and many fundamental questions remain unanswered. This paper reviews research dating back to the 1950's providing compelling evidence that cord factor (trehalose 6,6 dimycolate [TDM]) is essential for understanding tuberculosis. However, the original papers by Bloch and Noll were too far ahead of their time to have immediate impact. We can now recognize that the physical and biologic properties of cord factor are unprecedented in science, especially its ability to switch between two sets of biologic activities with changes in conformation. While TDM remains on organisms, it protects them from killing within macrophages, reduces antibiotic effectiveness and inhibits the stimulation of protective immune responses. If it comes off organisms and associates with lipid, TDM becomes a driver of tissue damage and necrosis. Studies emanating from cord factor research have produced (1) a rationale for improving vaccines, (2) an approach to new drugs that overcome natural resistance to antibiotics, (3) models of caseating granulomas that reproduce multiple manifestations of human tuberculosis. (4) evidence that TDM is a key T cell antigen in destructive lesions of tuberculosis, and (5) a new understanding of the pathology and pathogenesis of postprimary tuberculosis that can guide more informative studies of long standing mysteries of tuberculosis.

CD8+ Pagetoid Reticulosis Presenting as a Solitary Foot Plaque in a Young Woman.

Background: Pagetoid reticulosis is a rare variant of mycosis fungoides. This rare condition typically presents as a solitary plaque located on the extremities with an indolent clinical course (Woringer-Kolopp disease) or as a more generalized presentation with diffuse cutaneous involvement and a more aggressive clinical course (Ketron-Goodman disease). Purpose: To review the cutaneous manifestations, pathology, and treatment of localized pagetoid reticulosis. Methods: The authors describe a 24-year-old woman with a slowly enlarging, localized plaque of seven months duration, representing the localized form of pagetoid reticulosis with CD8+ immunophenotype. Results: The histological, immunohistochemical, and clinical features of the patient's skin lesion were characteristic for a diagnosis of Woringer-Kolopp disease. Systemic work-up for lymphoma was negative. Conclusion: Woringer-Kolopp disease is most commonly seen in middle-aged men as a solitary lesion of the extremities, and it should always be considered in the differential diagnosis when a patient presents with such a lesion. A histological analysis demonstrated atypical lymphocytes preferentially localized to the epidermis with a CD4+, CD8+, or CD4-/CD8- phenotype. The treatment of choice for a solitary lesion may be localized radiation therapy, but newer therapies, such as bexarotene, may warrant further investigation.

Quantitative MRI of spinal cord injury in a rat model: Correlative studies

Serial quantitative and correlative studies of experimental spinal cord injury (SCI) in rats were conducted using three-dimensional magnetic resonance imaging (MRI). Correlative measures included morphological histopathology, neurobehavioral measures of functional deficit, and biochemical assays for N-acetyl-aspartate (NAA), lactate, pyruvate, and ATP. A spinal cord injury device was characterized and provided a reproducible injury severity. Injuries were moderate and consistent to within $\pm$20% (standard deviation). For MRI, a three-dimensional implementation of the single spin-echo FATE (Fast optimum angle, short TE) pulse sequence was used for rapid acquisition, with a 128 x 128 x 32 (x,y,z) matrix size and a 0.21 x 0.21 x 1.5 mm resolution. These serial studies revealed a bimodal characteristic in the evolution in MRI pathology with time. Early and late phases of SCI pathology were clearly visualized in $T\sb2$-weighted MRI, and these corresponded to specific histopathological changes in the spinal cord. Centralized hypointense MRI regions correlated with evidence of hemorrhagic and necrotic tissue, while surrounding hyperintense regions represented edema or myelomalacia. Unexpectedly, $T\sb2$-weighted MRI pathology contrast at 24 hours after injury appeared to subside before peaking at 72 hours after injury. This change is likely attributable to ongoing secondary injury processes, which may alter local $T\sb2$ values or reduce the natural anisotropy of the spinal cord. MRI, functional, and histological measures all indicated that 72 hours after injury was the temporal maximum for quantitative measures of spinal cord pathology. Thereafter, significant improvement was seen only in neurobehavioral scores. Significant correlations were found between quantitated MRI pathology and histopathology. Also, NAA and lactate levels correlated with behavioral measures of the level of function deficit. Asymmetric (rostral/caudal) changes in NAA and lactate due to injury indicate that rostral and caudal segments from the injury site are affected differently by the injury. These studies indicate that volumetric quantitation of MRI pathology from $T\sb2$-weighted images may play an important role in early prediction of neurologic deficit and spinal cord pathology. The loss of $T\sb2$ contrast at 24 hours suggests MR may be able to detect certain delayed mechanisms of secondary injury which are not resolved by histopathology or other radiological modalities. Furthermore, in vivo proton magnetic resonance spectroscopy (MRS) studies of SCI may provide a valuable addition source of information about changes in regional spinal cord lactate and NAA levels, which are indicative of local metabolic and pathological changes. ^

The role of AT1 receptor autoantibodies in the pathophysiology of preeclampsia

Preeclampsia is a disease that affects 3–5% of all pregnancies. The cause is unknown and there is currently no treatment. The disease poses significant health risks to both the mother and the fetus. To date, research on the topic has not produced a convincing cause for the development of the hallmark symptoms of preeclampsia. The hypothesis of an agonistic autoimmune response to the AT1 receptor is presented. Immunoglobulin fractions from normotensive and preeclampsia patients were prepared for experimental tests. Model systems were tested in three categories to determine if AT 1 receptor specific activation and receptor-ligand interaction was caused by a suspected autoantibody. Activation was found in rat neonatal cardiornyocytes that caused an increased contraction rate. This activity was found in preeclampsia patients, absent in normotensive patients. The activation was antagonized by losartan, an AT1 receptor antagonist, and by epitope peptide competition of the receptor-ligand type interaction. This epitope was the 7 amino acid peptide fragment, AFHYESQ, a sequence present in the second extracellular loop of the AT1 receptor. The patterns of AT1 receptor activation were also found in a human trophoblast cell line, HTR8, with an effect on Pai-1 secretion, a factor that plays a role in preventing hypercoagulation. In human mesangial cells, the AT1 receptor autoantibody present in the immunoglobulin fraction from preeclampsia patients was found to stimulate the secretion of Pai-1, and IL-6, a factor that plays a role in the activation of an inflammatory response. This activity was found in samples from preeclampsia patients, but absent in normotensive patients. Tests including losartan, AFHYESQ, and a non-competitive peptide demonstrated that the secretion of Pai-1 and IL-6 met the criteria for AT1 receptor activation by the suspected agonistic autoantibody. These three model systems address relevant pathophysiology for preeclampsia patients, including increased cardiac output, abnormal placentation, and renal damage. The AT1 receptor agonistic autoantibody is potentially a key player in the development of the pathology and symptoms of preeclampsia. ^

AN INVESTIGATION OF THE IMPACT OF CHILDREN WITH BIRTH DEFECTS ON STRESS IN THEIR FAMILIES

A child with a birth defect places physical, financial and emotional stress upon the family. The purpose of this study was to assess the impact of a mildly handicapped child on the family's coping abilities.^ Two groups, 101 mothers of children with birth defects and 107 mothers of intact children, completed the Holroyd Questionnaire on Resources and Stress and the Luborsky Social Assets Scale. From these groups, 86 pairs were matched on four factors: the age (two to eight years) and sex of the study child and the mother's education and marital status.^ The children with birth defects had completed the diagnostic evaluation at the Meyer Center for Developmental Pediatrics, Texas Children's Hospital. Children with severe defects were excluded. The mean I.Q of the group was 88, s.d. 17; 17 children were mildly retarded and 35 had an I.Q. of 100 or above; areas of dysfunction included motor abnormalities, behavior disturbance, speech problems, and sensory impairments.^ The expected direction and statistically significant differences were obtained from the data for the matched pairs on the Q.R.S. scales. The mothers of children with a birth defect reported poor health, a negative attitude toward the child, being over-protective, financial problems and feeling a lack of social support and family integration. They perceived the child as socially obtrusive, limited as to occupational opportunities, and as having a difficult personality.^ The functioning levels of the handicapped children contributed to the respondent's problems. The child with behavior and speech problems but adequate intelligence was a situation which resulted in a poor health/mood of the mother. The mother's pessimism was related to the child's low intelligence.^ The social assets of the respondents with intact children were significantly higher than those of respondents of handicapped children. There was no relationship between the total social assets score and the scores on the Q.R.S. for mothers of handicapped children. These mothers did report poorer physical conditions, more smoking, and quarreling of their parents as they grew up. ^