Nikolaos Nikolaidis

Long-term Follow-up of Patients With Acute Hypertriglyceridemia-Induced Pancreatitis

Background An acute and potentially life-threatening complication of hypertriglyceridemia (HTG) is acute pancreatitis (AP). Hypertriglyceridemia, usually severe, may be primary in origin or secondary to alcohol abuse, diabetes mellitus, pregnancy, and use of drugs. Study The efficacy of treatment to prevent relapses in 17 patients with AP attributed to HTG was investigated in the current prospective study. The mean follow-up period of patients was 42 months. Hypertriglyceridemia-induced AP comprised 6.9% of all patients with AP (n = 246) hospitalized in our clinic during the study (6 years). Results Causative conditions of HTG-induced AP were familial HTG in eight patients, HTG caused by uncontrolled diabetes mellitus in five, HTG aggravated by drugs in two (one by tamoxifen and one by fluvastatin), familial hyperchylomicronemia (HCM) in one, and lipemia of pregnancy in one. During the acute phase of pancreatitis, patients underwent standard treatment. Thereafter, HTG was efficiently controlled with high dosages of fibrates or a fibrate plus acipimox, except for the patient with HCM, who was on a specific diet (the only source of fat was a special oil consisting of medium chain triglyceride) and taking a high dosage of acipimox. One of the patients died during the acute phase of pancreatitis with acute respiratory distress syndrome. During follow-up, maintenance treatment was successful and only one patient relapsed, because he discontinued diet and drug treatment. Conclusion Appropriate diet and drug treatment, including dose titration, of severe HTG is very effective in preventing relapses of HTG-induced AP.

Multi-view human movement recognition based on fuzzy distances and linear discriminant analysis

In this paper, a novel multi-view human movement recognition method is presented. A novel representation of multi-view human movement videos is proposed that is based on learning basic multi-view human movement primitives, called multi-view dynemes. The movement video is represented in a new feature space (called dyneme space) using these multi-view dynemes, thus producing a time invariant multi-view movement representation. Fuzzy distances from the multi-view dynemes are used to represent the human body postures in the dyneme space. Three variants of Linear Discriminant Analysis (LDA) are evaluated to achieve a discriminant movement representation in a low dimensionality space. The view identification problem is solved either by using a circular block shift procedure followed by the evaluation of the minimum Euclidean distance from any dyneme, or by exploiting the circular shift invariance property of the Discrete Fourier Transform (DFT). The discriminant movement representation combined with camera viewpoint identification and a nearest centroid classification step leads to a high human movement classification accuracy.

Action recognition on motion capture data using a dynemes and forward differences representation

In this paper we introduce a novel method for action/movement recognition in motion capture data. The joints orientation angles and the forward differences of these angles in different temporal scales are used to represent a motion capture sequence. Initially K-means is applied on training data to discover the most representative patterns on orientation angles and their forward differences. A novel K-means variant that takes into account the periodic nature of angular data is applied on the former. Each frame is then assigned to one or more of these patterns and histograms that describe the frequency of occurrence of these patterns for each movement are constructed. Nearest neighbour and SVM classification are used for action recognition on the test data. The effectiveness and robustness of this method is shown through extensive experimental results on four standard databases of motion capture data and various experimental setups.

Early versus delayed minimal enteral feeding and risk for necrotizing enterocolitis in preterm growth-restricted infants with abnormal antenatal Doppler results.

We studied the effect of early (< or = 5 days) versus delayed (> or = 6 days) initiation of minimal enteral feeding (MEF) on the incidence of necrotizing enterocolitis (NEC) and feeding intolerance in preterm infants with intrauterine growth restriction (IUGR) and abnormal antenatal Doppler results. We performed a randomized, nonblinded pilot trial of infants receiving early or delayed MEF in addition to parenteral feeding within 48 hours of life. Demographic data, maternal preeclampsia, antenatal steroid exposure, Doppler studies, as well as cases of NEC and feeding intolerance were all recorded. Of the 84 infants enrolled, 81 completed the study: 40 received early (median age: 2 days, range: 1 to 5 days) and 41 delayed (median age: 7 days, range: 6 to 14 days) MEF. The incidence of NEC and feeding intolerance was not significantly different between groups (p = 0.353 and p = 0.533, respectively). Birth weight was an independent risk factor for NEC in both groups. Early MEF of preterm infants with IUGR and abnormal antenatal Doppler results may not have a significant effect on the incidence of NEC or feeding intolerance. Furthermore, birth weight seems to be an independent risk factor for the development of NEC, irrespectively of the timing of MEF introduction.

Low-molecular-weight heparin (enoxaparin) as adjuvant therapy in the treatment of active ulcerative colitis: a randomized, controlled, comparative study.

Heparin could be beneficial to the treatment of active ulcerative colitis because of its anticoagulant, anti‐inflammatory and immunomodulatory properties.

Watermarking polygonal lines using Fourier descriptors

Digital products are easy to copy, reproduce, and maliciously process in a network environment. Over the past decade, watermarking has emerged as an important technology for protecting copyright of multimedia products. We present a method for embedding and detecting watermarks in vector graphics images containing polygonal lines, and present results from simulated attacks. Our proposed algorithm embeds watermarks in polygonal lines describing image contours. These contours are usually described in vector format. Our watermarking method slightly modifies the vertex coordinates of the polygonal line. We embed the watermark in the magnitude of the curves Fourier descriptors to exploit its location, scale, and rotation invariant properties. Our technique has certain similarities to bitmap image watermarking in the discrete Fourier transform (DFT) domain. However, its essentially different because it can be applied to vector rather than bitmap images. Furthermore, Fourier descriptor watermarking problems differ from DFT bitmap image watermarking problems.A method for watermarking of polygonal lines is proposed. The watermark is embedded in the Fourier descriptors of the polygonal line causing minor distortions to the coordinates of the vertices of the polygonal line. Watermarks generated by this technique can be successfully detected even after rotation, translation, scaling and reflection of the host polygonal line.

Content-Based Video Copy Detection - A Survey

In the presence of overwhelming amount of digital video data, the need for automated procedures to protect owners against unauthorized use of their content. to enable content publishers and distributors to monitor broadcast usage of videos and to help businesses manage storage of videos in large databases has become ever more critical Till now, two technical approaches have been proposed toward these goals, namely, watermarking-based systems and content-based copy detection (CBCD). Among them, the former one has been more thoroughly studied and explored, while the latter one is still in its early stages. This chapter reviews existing video copy detection systems, investigates some typical CBCD algorithms, compares the algorithms through appropriate performance metrics, and lists some challenges and open issues in this research field.

Adefovir dipivoxil added to ongoing lamivudine therapy in patients with lamivudine-resistant hepatitis B e antigen-negative chronic hepatitis B

Background : Long‐term treatment with lamivudine is required to control viral replication in patients with hepatitis B e antigen‐negative chronic hepatitis B, but is associated with a high rate of viral resistance. The role of adefovir dipivoxil in these patients has not been definitively evaluated.

Is the use of rFVIIa safe and effective in bleeding neonates? A retrospective series of 8 cases.

Background Recombinant activated factor VII (rFVIIa), originally developed for the treatment of life-threatening bleeding in hemophilic patients with inhibitors to factors VIII or IX, has been increasingly used to control hemorrhage unresponsive to conventional treatment, in the absence of a defined coagulopathy or thrombocytopathy. To date, clinical experience of rFVIIa administration in neonates, especially preterms, is rather limited, because of the lack of controlled studies and based solely on some published case reports and 1 prospective pilot study. The objective of this study was to retrospectively evaluate the clinical outcome of newborns treated with recombinant activated factor VII for intractable bleeding or severe coagulation disturbances, resistant to conventional hemostatic therapy. Methods The medical records of 8 neonates treated with rFVIIa (100  μg/kg) were retrospectively reviewed for the course of hemorrhage and the hemostatic interventions performed before and up to 24 hours after the administration rFVIIa. Coagulation parameters of 3 different time-points were assessed and compared: before administration of any blood product (time-point 1), before administration of the first dose of rFVIIa (time-point 2), and 4 hours after the administration of the last dose of rFVIIa (time-point 3). The safety and tolerability profile of rFVIIa in bleeding neonates was also evaluated. Results Six preterm and 2 term patients were included in the study. Seven patients presented with refractory bleeding and 1 was diagnosed with severe coagulopathy unresponsive to the conventional treatment. Prompt hemostasis was achieved in half of the patients with their coagulation profile being restored within 4 hours after the administration of the first dose of rFVIIa. Improvement in prothrombin time, activated partial thromboplastin time, and fibrinogen after rFVIIa administration was statistically significant, as compared with that observed after conventional treatment. No major safety issues were observed during the study. All 8 patients survived and had their hemorrhage or coagulopathy controlled within 4 hours after transfusion of the last dose of rFVIIa. Conclusions In this study, the hemostatic agent rFVIIa was well-tolerated and behaved in a safe and efficacious manner in all infants treated for life-threatening bleeding and coagulation disorders. Future prospective controlled trials are needed to determine the efficacy, safety, tolerability, and possibly the optimal dose and timing of rFVIIa administration.

Small-Duct Primary Sclerosing Cholangitis. A Single-Center Seven-Year Experience

Patients with cholestatic liver function tests and histological features of primary sclerosing cholangitis (PSC) but without the typical cholangiographic changes are considered to have small-duct PSC. The incidence of small-duct PSC and the natural history still is not known. We performed a retrospective search for patients diagnosed with small-duct PSC between January 1997 and December 2003. The diagnosis of small-duct PSC was based on biochemical features of chronic cholestasis, liver biopsy findings consistent with PSC, and a normal cholangiogram on endoscopic retrograde cholangiography. Six patients fulfilled the diagnostic criteria for small-duct PSC. All patients received medical therapy. After a mean follow-up time of 26.0 ± 29.8 months (range, 7–84 months), all patients are alive. Repeated liver biopsy was performed in one patient, 58 months after the initial one, and disclosed amelioration of histological findings (reduction in the Ludwig fibrosis score from 4 to 2). During follow-up symptoms disappeared in all patients who were symptomatic at diagnosis; none of those who were asymptomatic at diagnosis developed symptoms. At the time of last follow-up all patients showed significant improvement of their biochemical variables compared to baseline. Administration of aminosalicylates seemed to be of benefit irrespective of the presence of inflammatory bowel disease. No patients underwent liver transplantation or developed cholangiocarcinoma. Even though our study included a low number of patients and the follow-up time was relatively short, we can suggest that small-duct PSC rarely progresses to large-duct PSC and does not seem to be associated with development of cholangiocarcinoma. It thus seems to represent a separate entity with a favorable prognosis.