Biofunctionalization of materials for implants using engineered peptides

Uncontrolled interactions between synthetic materials and human tissues are a major concern for implants and tissue engineering. The most successful approaches to circumvent this issue involve the modification of the implant or scaffold surfaces with various functional molecules, such as anti-fouling polymers or cell growth factors. To date, such techniques have relied on surface immobilization methods that are often applicable only to a limited range of materials and require the presence of specific functional groups, synthetic pathways or biologically hostile environments. In this study we have used peptide motifs that have been selected to bind to gold, platinum, glass and titanium to modify surfaces with poly(ethylene glycol) anti-fouling polymer and the integrin-binding RGD sequence. The peptides have several advantages over conventional molecular immobilization techniques; they require no biologically hostile environments to bind, are specific to their substrates and could be adapted to carry various active entities. We successfully imparted cell-resistant properties to gold and platinum surfaces using gold- and platinum-binding peptides, respectively, in conjunction with PEG. We also induced a several-fold increase in the number and spreading of fibroblast cells on glass and titanium surfaces using quartz and titanium-binding peptides in conjunction with the integrin ligand RGD. The results presented here indicate that control over the extent of cell–material interactions can be achieved by relatively simple and biocompatible surface modification procedures using inorganic binding peptides as linker molecules.     

Universal Markers of Thyroid Malignancies: Galectin-3, HBME-1, and Cytokeratin-19

Difficulties in diagnosis of thyroid lesions, even with histologic analysis, are well known. This study has been carried on to evaluate the role of immunohistochemical markers including galectin-3, Hector Battifora mesothelial cell-1 (HBME-1), and cytokeratin-19 in the diagnosis and differential diagnosis of benign and malignant thyroid lesions. The expressions of galectin-3, HBME-1, and cytokeratin-19 were tested in formalin-fixed, paraffin-embedded tissues from 458 surgically resected thyroid lesions including non-neoplastic and neoplastic lesions. Immunostaining with standard avidin–biotin complex technique was performed by using monoclonal antibodies. In malignant neoplastic thyroid lesions, galectin-3, HBME-1, and cytokeratin-19 were diffusely expressed in general. Diffuse expression rates of these three markers were 72.3% (47/65), 70.7% (46/65), and 76.9% (50/65), respectively. The use of galectin-3, HBME-1, and cytokeratin-19 may provide significant contributions in the differential diagnosis of malignant thyroid tumors. Although focal galectin-3, HBME-1, and cytokeratin-19 expression may be encountered in benign lesions, diffuse positive reactions for these three markers are characteristic of malignant lesions. It has concluded that cytokeratin-19 alone and its combinations with other markers were more sensitive in accurate diagnosis of papillary carcinoma than the other combinations; meanwhile, there were similar results for follicular carcinomas with HBME-1 alone and its combinations.     

Lateralization of Neurobiological Response in Adolescents with Post-Traumatic Stress Disorder Related to Severe Childhood Sexual Abuse: the Tri-Modal Reaction (T-MR) Model of Protection

This study inquires into neurobiological response to stress and its clinical correlates among adolescents with post-traumatic stress disorder (PTSD). Structural magnetic resonance imaging (MRI) measures of cerebral anatomy were carried out on 23 female adolescents with PTSD related to severe childhood sexual abuse and 21 matched healthy controls. Clinician Administered PTSD Scale for Children and Adolescents, Adolescent Dissociative Experiences Scale, Childhood Trauma Questionnaire, Schedule for Affective Disorders and Schizophrenia for School Age Children, Beck Depression Scale, and a set of neuro-cognitive tests were administered to all participants. Compared to controls, PTSD group bilaterally had smaller amygdala, hippocampus, anterior cingulate, and thinner prefrontal cortex but normal thalamus. Further analyses within the PTSD group suggested an association between symptoms of PTSD and sizes of right brain structures including smaller amygdala but larger hippocampus and anterior cingulate. Thinner right prefrontal cortex and larger right thalamus seemed to be related to denial and response prevention, respectively. Being related to both hemispheres, dissociative amnesia was negatively associated with proportion of the right amygdala to right thalamus and to both left and right prefrontal cortex. Suggesting a neuro-protective effect against traumatic stress at least through adolescence, depersonalization–derealization and identity alteration were correlated with thicker left prefrontal cortex. Unlike the lateralization within PTSD group, correlations between regions of interest were rather symmetrical in controls. The graded response to stress seemed to be aimed at mental protection by lateralization of brain functions and possibly diminished connection between two hemispheres. A Tri-Modal Reaction (T-MR) Model of protection is proposed.     

Pandemic influenza H1N1 2009 virus infection in pregnancy in Turkey

ObjectivesTo describe the clinical characteristics of the pregnant women who were hospitalized in a tertiary referral hospital with pandemic influenza H1N1 2009 virus infection and neonatal outcomes from October 2009 to December 2009 during which the pandemic influenza cases peaked in Turkey.Materials and MethodsTwenty-five pregnant women who were hospitalized with influenza-like illness and who had laboratory confirmation for pandemic influenza H1N1 virus infection were evaluated prospectively.ResultsOf the 25 patients, 4 (16%) were in the first trimester, 8 (32%) were in the second trimester, and 13 (52%) were in the third trimester. The median time from the onset of symptoms to the initiation of antiviral therapy was 1 day (range 1–9 days). Nineteen (76%) patients received oseltamivir treatment. It took 1.6 days on the average for the fever defervescence after the initiation of treatment or hospitalization. Of the 14 patients who underwent chest radiography, three had findings consistent with pneumonia. The mean duration of hospitalization was 4.8 days. Four women (16%) were admitted to an intensive care unit, but there were no maternal or neonatal deaths in this series. At the time of their H1N1 hospitalization, seven women delivered by cesarean at 33–40 weeks gestation, two vaginally at 38 weeks gestation, and two had an abortion at 10 weeks and 16 weeks of gestation, respectively. None of the infants had any evidence of influenza infection.ConclusionPregnant women are at increased risk for complications from pandemic influenza H1N1 virus infection. Timely medical attention with early recourse to antiviral therapy is associated with a better outcome in H1N1-affected pregnant women.     

Role of early EEG and neuroimaging in determination of prognosis in children with complex febrile seizure

BACKGROUND: The present study investigates the role of early use of EEG in children with no known neuropathology prior to the first CFS, and the contribution made by computed tomography (CT) and magnetic resonance imaging (MRI) to treatment and prognosis. METHODS: Over a period of 7 years, the authors evaluated 159 children (age range: 2 months-5 years) who were being treated for CFS at Haydarpasa Numune Training and Research Hospital, Pediatrics Clinic, Istanbul, Turkey, and who had no previously known neurological disorder. Patients who presented with febrile seizure were determined to have CFS if they fulfilled the following criteria: <3 months of age when seizure occurred, duration of seizure >/=15 min, more than one seizure occurred during a single episode of illness, or focal seizures and postictal neurological deficit was found. EEG was performed on all patients. CT was performed on the patients who had postictal neurologic deficit or focal seizures. Cranial MRI was performed on patients who had focal findings in their EEGs. RESULTS: Electroencephalogram abnormality was found in 71 cases; 51 of these were diagnosed with epilepsy during follow up. Six of the 16 cases whose EEGs were abnormal between days 2 and 6 were diagnosed with epilepsy. Twenty of the 30 cases whose EEGs were abnormal between days 7 and 10 were diagnosed with epilepsy. All 25 cases who had abnormal EEGs after day 11 were diagnosed with epilepsy. CT was performed for 36 patients, of which five were found to have pathological changes. Pathological changes were detected in two of the nine patients who had cranial MRI. Patients who received CT or MRI were all diagnosed with epilepsy during follow up. CONCLUSION: The results suggest that if neurological examination of CFS patients are normal after their clinical status has stabilised, EEG should be performed after 7 days at the earliest, however for the most accurate diagnosis EEG should be performed 10 days after CFS. The most important predictor for neuroimaging was found to be detection of postictal neurologic deficit. MRI had no advantages over CT in first treating CFS in the emergency unit.     

Hemophagocytic lymphohistiocytosis in 2 pediatric patients secondary to hepatitis A virus infection

Hemophagocytic lymphohistiocytosis (HLH) is a rare clinical syndrome characterized by uncontrolled activation of cytotoxic T cells and antigen-presenting cells. Common clinical manifestations include high fever, maculopapular rash, neurological symptoms, coagulopathy, and abnormal liver function tests [1]. HLH can be either primary, that is, due to an underlying genetic defect, or secondary, associated with malignancies, autoimmune diseases, or infections. The true incidence of secondary HLH is difficult to define. Infection associated HLH are most commonly associated with viral infections mainly of the herpes group, with Epstein-Barr virus (EBV) that is proposed to be the most common cause [2]. Despite the high incidence of hepatitis A virus (HAV) infection in the pediatric population in general, there are few pediatric case reports in the literature about HAV-associated hemophagocytic syndrome [3]. We encountered 2 patients with HAV-associated hemophagocytic syndrome.     

Prognostic importance of tumor angiogenesis in breast carcinoma with adjuvant chemotherapy

Tumor angiogenesis is believed to be related to prognostic factors involved in tumor development and metastasis. Using immunohistochemical methods, we evaluated tumor angiogenesis in 42 early invasive breast cancer patients (T1-2, NO-1-2, M0). Four patients received tamoxifen, 25 patients received CAF or CA, and 15 patients received CMF as adjuvant therapy. The median follow-up was 47 (range 24-119) months. Ten patients (43.5%) in the node-positive group and 2 patients (10.5%) in the node-negative group relapsed (p = 0.019). The mean microvessel count (MVC) was 60.3 3.05 per 200x field (range: 16-95). MVCs of postmenopausal and premenopausal patients were 50.13 +/- 5.74 and 68.64 +/- 4.11, respectively, in the axillary lymph node (ALN)-negative patient group (p = 0.04). Staining was moderate to strong in 13 (68%) ALN-negative and in 17 (74%) ALN-positive patients (p > 0.05), and was also moderate to strong in 82% of premenopausal patients and in 50% of postmenopausal patients (p = 0.037). There was no significant relationship between angiogenesis and p53, nor was angiogenesis significantly associated with the patient ER status and tumor size. No significant correlations were found between OS/DFS and Factor VIII staining or p53 (log rank test, p > 0.05). Of all ALN-negative patients with increased angiogenesis, one patient of the CMF group relapsed, but no recurrence occurred in patients undergoing anthracycline-based chemotherapy (p > 0.05). On the other hand, of all ALN-positive patients with increased angiogenesis, 5/14 patients treated with anthracylcine and 2/2 CMF-treated patients relapsed (p = 0.175). Despite the statistical insignificance, anthracycline-based adjuvant chemotherapy appears to be more effective than CMF as regards relapse prevention particularly in early ALN-positive breast cancer patients with increased angiogenesis. Additional studies are necessary to demonstrate the clinical importance of angiogenesis.     

Prediction of gestational diabetes mellitus by first trimester serum secreted frizzle-related protein-5 levels

Objective: The main aim of this study was to investigate the first trimester maternal serum secreted frizzle-related protein-5 (Sfrp-5) levels and to evaluate the predictive value on the subsequently developed gestational diabetes mellitus (GDM).

Methods: A total of 40 pregnant women who subsequently developed GDM and 44 age- and pre-pregnancy BMI-matched healthy pregnant women were enrolled in this prospective case-control study. First trimester serum Sfrp-5 levels were evaluated to determine if there is an association with the onset of GDM, by using logistic regression analysis.

Results: Decreased first trimester serum Sfrp-5 levels (OR?=?14.332, 95%CI: 4.166–49.301, p?<?0.001) were found to be significantly associated with the increased risk of GDM. There were no statistically significant differences in serum Sfrp-5 levels between the diet- and insulin-treated GDM groups and also serum Sfrp-5 levels were not found to be predictive for adverse perinatal outcomes (p?>?0.05).

Conclusions: Decreased first trimester serum Sfrp-5 levels are significantly associated with the increased risk of GDM.