Rapid ubiquitination of Syk following GPVI activation in platelets

Spleen tyrosine kinase (Syk) activation is a key intermediate step in the activation of platelets by the physiologic agonist collagen. We have found that Syk is rapidly ubiquitinated upon activation of platelets by collagen, collagen-related peptide (CRP), and convulxin. The Src family kinase inhibitors prevented Syk phosphorylation and its ubiquitination, indicating that the process is downstream of Src kinases. The ubiquitination of Syk did not cause degradation of the protein as evidenced by the lack of effect of proteasomal and lysosomal inhibitors. We separated ubiquitinated Syk from its nonubiquitinated counterpart and used an in vitro kinase assay to compare their activities. We found that the ubiquitinated Syk appeared to be about 5-fold more active. Using a phosphospecific antibody to Syk (Tyr525/Tyr526) that measures activated Syk, we found that most (60%-75%) of the active Syk is in the ubiquitinated fraction. This result explains the apparent high specific activity of ubiquitinated Syk. In c-Cbl-deficient mice, Syk is not ubiquitinated, implicating c-Cbl as the E3 ligase involved in Syk ubiquitination. Furthermore, Syk is not dephosphorylated in these mice. We propose that c-Cbl plays a regulatory role in glycoprotein VI (GPVI)/Fc receptor gamma (FcRgamma)-chain-dependent platelet activation through its interaction with Syk.     

Surgical variables affecting swallowing in patients treated for oral/oropharyngeal cancer

BACKGROUND: Postoperative swallowing function may be influenced by a number of treatment variables; this study examines the relationship of various treatment factors to measures of swallow function. METHODS: Swallowing was examined with the modified barium swallow procedure in 144 patients surgically treated for oral or oropharyngeal cancer 3 months after healing. Univariate and multivariate correlations were used to examine the relationship between swallowing function and treatment. RESULTS: Percent tongue base resected and total volume resected were most often correlated with swallowing function in the univariate analyses. Multivariate analyses identified the following combinations with the strongest correlations: (1) percent tongue base resected and closure type for liquids; (2) percent tongue base resected and unreconstructed mandible for pastes; (3) total volume resected, percent lateral floor of mouth resected, and postoperative radiotherapy dose for masticated boluses. CONCLUSIONS: Total volume resected and percent tongue base resected had a profound impact on postoperative swallowing function. Combinations of percent tongue base resected with other surgical variables had the strongest relationships with overall swallowing function.     

Dimethylthiourea inhibition of melanoma cell growth in vitro and in vivo

The effect of dimethylthiourea (DMTU), an agent known as a hydroxyl radical scavenger, was determined on growth and differentiation of the B16 murine melanoma cell line. DMTU inhibited melanoma cell growth in vitro and induced changes in the morphology of melanoma cells. Prolonged treatment of cells with DMTU resulted in an increase in melanin content. DMTU-treated melanoma cells had a decreased capacity to form tumors in syngeneic mice. Systemic administration of DMT to C57BL/6J mice inoculated with melanoma cells resulted in a delay in tumor appearance and a prolongation of survival. The doses of DMTU used did not cause any apparent toxic effects. A potential therapeutic role for DMTU in the treatment of melanoma is suggested.     

An exploratory study of body awareness in persons with heart failure treated medically or with transplantation

Heart failure is a chronic disabling problem afflicting a growing number of adults. These individuals experience episodes of exacerbation demonstrated by increasing shortness of breath, fatigue, and fluid retention. The symptoms often develop in a slow and insidious manner making perception of worsening difficult to determine. Theoretically, an increase in body awareness may help individuals recognize symptoms of worsening heart failure earlier, but it is not known whether increased body awareness leads to somatization, an abnormal dwelling on body symptoms. This study was conducted to describe body awareness in 90 persons with heart failure or after transplant. We found that the Body Awareness Quesionnaire was a reliable measure of this concept in this sample. When body awareness was examined for age, gender, and treatment (HF or transplant) group were examined, no significant differences were found. Furthermore, there were no significant relationships between body awarenss and negative moods such as anxiety, depression, or anger. Interventions to enhance body awareness may be a fruitful new direction that will improve symptom recognition without increasing somatization in persons with heart failure.     

Sex differences in infection and sepsis

Sex and gender-based differences in responses to infection and sepsis are evident. Estrogens increase immune function, sometimes to the point of inducing autoimmune disease. Testosterone suppresses immune function, sometimes leading to a worsened outcome following traumatic injury. Therapies using sex hormones to improve outcomes after sepsis and hemorrhagic shock and to reduce exacerbations of autoimmune diseases are being studied. Differences in sex hormone levels may not tell the whole story. Studies of immune function in girls and boys before puberty may be helpful. Differences found early might indicate that factors other than estrogen and androgen levels are contributing. Variations in societal role acculturation and exposures that are gender based also may be involved. Clinicians must consider sex and gender when attempting to determine the risk of infection, sepsis, and immune dysfunction in populations. Clinical applications of sex and gender differences are just beginning to occur with the genesis of sex hormone-based treatments. The large-scale efficacy of such treatments has yet to be reported. Innovative strategies based on sex or gender differences in immune responses may soon be available and may lead to essential data for clinical decision making. The impact of sex and gender differences on long-term health outcomes remains to be seen.     

The evolving role of genetics in the diagnosis and management of heart disease

The role of genetics in heart disease diagnosis and management is expanding daily. Clear genetic components have been found for diseases such as hypertrophic cardiomyopathy, heart failure, and coronary artery disease. Rhythm disturbances with genetic components are atrial fibrillation and long QT syndrome. Gene therapies to treat cardiac diseases include those designed to prevent vein graft stenosis and those that promote coronary angiogenesis.     

Role of transforming growth factor beta in the growth inhibition of human breast cancer cells by basic fibroblast growth factor

Recent studies from our laboratory have revealed that basic fibroblast growth factor (bFGF) selectively inhibits the proliferation of human MCF-7 breast cancer cells. It has also been shown to enhance cis-platinum-induced apoptosis, decrease levels of the anti-apoptotic gene product bcl-2, and increase levels of the cyclin-dependent protein kinase inhibitor p21/WAF1/Cip1. Transforming growth factor beta-1 (TGF₁), a cell growth regulator has been found to have an inhibitory effect on breast cancer cells. The aim of the present study was to evaluate the possible role of TGF₁ in the antiproliferative effects of bFGF in MCF-7 breast cancer cells. We found that exogenous, as well as endogenous (overexpressed) bFGF increased TGF₁ mRNA expression in the cells and enhanced the secretion of TGF₁ into culture medium. However, exogenous addition of TGF₁ neither led to a decrease in bcl-2 nor induced an increase in the levels of p21/WAF1/Cip1 and neutralizing antibodies to TGF₁, did not reverse bFGF-induced G₁ arrest nor the increase in p21/WAF1/Cip1 level. In contrast, antisense oligonucleotides to TGF₁ abrogated the antiproliferative effects and inhibited the induction of p21/WAF1/Cip1 by bFGF in MCF-7 cells. These data suggest that the anti-proliferative effects of bFGF in human MCF-7 breast cancer cells are mediated by endogenous TGF₁, while exogenous TGF₁ does not mimic all the effects of bFGF on these breast cancer cells. These findings provide an important basis for further investigations into the autocrine and paracrine processes that control the growth of breast cancer cells.     

Combined administration of platelet rich plasma and autologous bone marrow aspirate concentrate for spinal cord injury: a descriptive case series

Administration of platelet rich plasma(PRP) and bone marrow aspirate concentrate(BMAC) has shown some promise in the treatment of neurological conditions; however, there is limited information on combined administration. As such, the purpose of this study was to assess safety and functional outcomes for patients administered combined autologous PRP and BMAC for spinal cord injury(SCI). This retrospective case series included seven patients who received combined treatment of autologous PRP and BMAC via intravenous and intrathecal administration as salvage therapy for SCI. Patients were reviewed for adverse reactions and clinical outcomes using the Oswestry Disability Index(ODI) for up to 1 year, as permitted by availability of follow-up data. Injury levels ranged from C3 through T11, and elapsed time between injury and salvage therapy ranged from 2.4 months to 6.2 years. Post-procedure complications were mild and rare, consisting only of self-limited headache and subjective memory impairment in one patient. Four patients experienced severe disability prior to PRP combined with BMAC injection, as evidenced by high( 48/100) Oswestry Disability Index scores. Longitudinal Oswestry Disability Index scores for two patients with incomplete SCI at C6 and C7, both of whom had cervical spine injuries, demonstrated a decrease of 28–40% following salvage therapy, representing an improvement from severe to minimal disability. In conclusion, intrathecal/intravenous co-administration of PRP and BMAC resulted in no significant complications and may have had some clinical benefits. Larger clinical studies are needed to further test this method of treatment for patients with SCI who otherwise have limited meaningful treatment options. This study was reviewed and approved by the Ohio Health Institutional Review Board(IRB No. 1204946) on May 16, 2018.