A novel approach based on recurrent neural networks applied to nonlinear systems optimization

This paper presents an efficient approach based on recurrent neural network for solving nonlinear optimization. More specifically, a modified Hopfield network is developed and its internal parameters are computed using the valid subspace technique. These parameters guarantee the convergence of the network to the equilibrium points that represent an optimal feasible solution. The main advantage of the developed network is that it treats optimization and constraint terms in different stages with no interference with each other. Moreover, the proposed approach does not require specification of penalty and weighting parameters for its initialization. A study of the modified Hopfield model is also developed to analyze its stability and convergence. Simulation results are provided to demonstrate the performance of the proposed neural network. (c) 2005 Elsevier B.V. All rights reserved.

Design and analysis of an efficient neural network model for solving nonlinear optimization problems

This paper presents an efficient approach based on a recurrent neural network for solving constrained nonlinear optimization. More specifically, a modified Hopfield network is developed, and its internal parameters are computed using the valid-subspace technique. These parameters guarantee the convergence of the network to the equilibrium points that represent an optimal feasible solution. The main advantage of the developed network is that it handles optimization and constraint terms in different stages with no interference from each other. Moreover, the proposed approach does not require specification for penalty and weighting parameters for its initialization. A study of the modified Hopfield model is also developed to analyse its stability and convergence. Simulation results are provided to demonstrate the performance of the proposed neural network.

Heart Failure After Myocardial Infarction: Clinical Implications and Treatment

Heart failure is a frequent complication of myocardial infarction. Several factors, such as recurrent myocardial ischemia, infarct size, ventricular remodeling, stunned myocardium, mechanical complications, and hibernating myocardium influence the appearance of left ventricular systolic dysfunction after myocardial infarction. Importantly, its presence increases the risk of death by at least 3- to 4-fold. The knowledge of the mechanisms and clinical features are essential for the diagnosis and treatment of left ventricular dysfunction and heart failure after myocardial infarction. Therefore, this review will focus on the clinical implications and treatment of heart failure after myocardial infarction.

Venous ulcer: clinical characteristics and risk factors

BackgroundLower limb venous ulceration ranks among the 10 most common medical problems in Western countries and has significant socioeconomic impact. The aim of this study was to identify the risk factors for unhealed, recurrent, and large ulcers and to characterize patients with active or recently healed venous ulcers.MethodsWe identified 97 patients and assessed 103 ulcerated limbs in 90 patients. All patients underwent clinical examination, arterial and venous system evaluation, ankle-brachial index determination, and ultrasound of the affected limb. Clinical characteristics included age, gender, race, ulcer duration, time since first episode, history of recurrence, localization of ulcer, ulcer area, eczema, ochre dermatitis, lipodermatosclerosis, pain, body mass index, and medical history data. Risk factors were identified by univariate analysis and estimated odds ratios.ResultsWe assessed 90 patients (103 limbs) with active or healed venous leg ulcers, of whom 84.4% were Caucasian and 68.9% were female. Mean age was 56.0 +/- 13.3 years. Ulcers had remained unhealed for < 1 year in 40.7%. Lipodermatosclerosis, lower limb hyperpigmentation, edema, and eczema were seen in 96.7%, 95.6%, 94.4%, and 51.1% of patients, respectively. Pain was a frequent symptom in 74.4%. Body mass index was assessed in 85 patients: 30.6% were slightly, 36.5% moderately, and 7% severely obese. Patient age > 60 years (odds ratio [OR] 4.0), extensive lipodermatosclerosis (OR 8.7), and previous history of ulceration (OR 19.9) were risk factors for unhealed ulcers. Time since first ulcer episode >= 2 years (OR 29.2) and incompetence of venous systems (OR 1.6) were risk factors for recurrence.ConclusionsLongstanding and large ulcers and recurrences are the main problems encountered by venous ulcer patients. Severe lipodermatosclerosis, previous ulcer history, and time since first ulcer episode >= 2 years are significant risk factors.

Granulocytic sarcoma of the small intestine with CBF beta/MYH11 fusion gene: report of an aleukaemic case and review of the literature

Granulocytic sarcomas (GS) are rare extramedullary tumours composed of immature myeloid cells. Inversion of chromosome 16 [inv(16)] is a cytogenetic marker for M4Eo subtype of acute myeloid leukaemia (AML). The possibility of an association between the development of granulocytic sarcoma of the small intestine (GSSI) and the M4Eo subtype of AML was suggested in nine previous case reports.Here we report an aleukaemic case of GSSI with inv(16) and its molecular equivalent, the CBFbeta/MYH11 fusion gene, detected by reverse transcriptase-polymerase chain reaction (RT-PCR), that after treatment with conventional AML chemotherapy followed by autologous bone marrow transplantation, achieved complete haematological and molecular remission on bone marrow examination. After chemotherapy, a thickened ileum wall positive for CBFbeta/MYH11 on tumour mass samples was still observed on computed tomography (CT) studies, raising the question of residual GS representing a reservoir of malignant cells. This case demonstrates the critical need of multidisciplinary diagnosis and follow-up of this entity combining immunopathologic, cytogenetic and molecular studies, reinforcing the potentiality of risk-adapted therapy strategies, as it is increasingly claimed for patients with overt AML. (C) 2003 Elsevier Ltd. All rights reserved.

Clinical presentation and salivary gland histopathology of paediatric primary Sjogren's syndrome

ObjectiveExplore the presentation, diagnostic criteria and exocrine gland histopathology of paediatric primary Sjogren's syndrome (PPSjS).MethodsA case series of 8 children is reported and American-European Consensus Group (AECG-2002) criteria were examined, as well as minor labial salivary and lachrymal gland biopsies, which were scored by a pathologist blinded to outcome. For all cases, connective tissue diseases and parotid-related infectious disease were excluded.ResultsAge at onset varied from 5-13 years old; 6 were females, all followed from diagnosis up to the last visit (1-10 years). The main features at presentation were recurrent tender parotid swelling and sialectasis imaging, with decreased salivary function assessed by Tc-99 scintigraphy. Mild sicca symptoms were observed in 4/8 cases. Systemic features, including fatigue, myalgia, arthritis, tenosynovitis, joint contractures, transient Raynaud's and high ESR, were recorded at onset. Autoantibody profile was unremarkable for diagnosis, while lymphocytic infiltration of labial salivary glands and sialectasis were observed in all biopsies (8/8). In lachrymal glands, massive lymphocytic infiltration and lymphocytic gastritis were observed during complementary assessment. Flares were treated with low dose steroids and long-term use of hydroxychloroquine (5/8), although only 318 fulfilled AECG-2002 diagnostic criteria, throughout the disease course.ConclusionPPSjS is rare, slowly progressive and its early presentation is variable. Standardised diagnostic algorithms should include recurrent parotid swelling and early diagnosis should rely mostly on salivary and lachrymal gland histopathology in this age group.

Remission status follow-up in children with juvenile idiopathic arthritis

Objective: To characterize articular and systemic inflammatory activity in juvenile idiopathic arthritis (JIA), identifying remission status with and without medication.Methods: A total of 165 JIA cases, followed for a mean period of 3.6 years, were reviewed in order to characterize episodes of inactivity and clinical remission on and off medication. The resulting data were analyzed by means of descriptive statistics, survival analysis, by comparison of Kaplan-Meier curves, log rank testing and binary logistic regression;analysis in order to identify predictive factors for remission or persistent activity.Results: One hundred and eight of the cases reviewed fulfilled the inclusion criteria: 57 patients (52.7%) exhibited a total of 71 episodes of inactivity, with a mean of 2.9 years per episode; 36 inactivity episodes (50.7%) resulted in clinical remission off medication, 35% of which were of the persistent oligoarticular subtype. The probability of clinical remission on medication over 2 years was 81, 82, 97 and 83% for cases of persistent oligoarticular, extended oligoarticular, polyarticular and systemicJIA, respectively. The probability of clinical remission off medication 5 years after onset of remission was 40 and 67% for patients with persistent oligoarticular and systemic JIA, respectively. Persistent disease activity was significantly associated with the use of an anti-rheumatic drug combination. Age at JIA onset was the only factor that predicted clinical remission (p = 0.002).Conclusions: In this cohort, the probability of JIA progressing to clinical remission was greater for the persistent oligoarticular and systemic subtypes, when compared with polyarticular cases.

Classic and molecular cytogenetic analyses reveal chromosomal gains and losses correlated with survival in head and neck cancer patients

Purpose: Genetic biomarkers of head and neck tumors could be useful for distinguishing among patients with similar clinical and histopathologic characteristics but having differential probabilities of survival. The purpose of this study was to investigate chromosomal alterations in head and neck carcinomas and to correlate the results with clinical and epidentiologic variables.Experimental Design: Cytogenetic analysis of short-term cultures from 64 primary untreated head and neck squamous cell carcinomas was used to determine the overall pattern of chromosome aberrations. A representative subset of tumors was analyzed in detail by spectral karyotyping and/or confirmatory fluorescence in situ hybridization analysis.Results: Recurrent losses of chromosomes Y (26 cases) and 19 (14 cases), and gains of chromosomes 22 (23 cases), 8 and 20 (11 cases each) were observed. The most frequent structural aberration was del(22)(q13.1) followed by rearrangements involving 6q and 12p. The presence of specific cytogenetic aberrations was found to correlate significantly with an unfavorable outcome. There was a significant association between survival and gains in chromosomes 10 (P = 0.008) and 20 (P = 0.002) and losses of chromosomes 15 (P = 0.005) and 22 (P = 0.021). Univariate analysis indicated that acquisition of monosomy 17 was a significant (P = 0.0012) factor for patients with a previous family history of cancer.Conclusions: the significant associations found in this study emphasize that alterations of distinct regions of the genome may be genetic biomarkers for a poor prognosis. Losses of chromosomes 17 and 22 can be associated with a family history of cancer.

Evaluation of renal and hepatic functions in dogs naturally infected by visceral leishmaniasis submitted to treatment with meglumine antimoniate

The present study aimed to evaluate the renal and hepatic responses in eight dogs with visceral leishmaniasis submitted to treatment with meglumine antimoniate and to verify the occurrence of possible side effects. Urinalysis, hepatic and renal function tests were carried out in all animals at up to seven moments. After the end of a six-month observation period, all dogs were euthanized. Before the beginning of the experiment urinary and biochemical alterations were observed in four dogs due to the changes caused by the parasite itself. These alterations included the presence of renal cells, cylindruria, proteinuria, azotemia, hyperproteinemia, and hypoalbuminemia. One dog died on the third day after treatment because an aggravation of the clinical picture, probably due to the medication. During the course of the study, an increase in hepatic enzymes was verified in two animals. Sixty days after the beginning of the treatment four dogs showed remission of clinical signs. The other three were asymptomatic with persistent biochemical alterations. From these, two presented recurrence of clinical signs about 150 days after the beginning of the treatment while in the other, hyperproteinemia persisted. Meglumine antimoniate was not efficient to treat dogs with severe renal dysfunction and the side effects observed were pain at the site of injection and the probable transient hepatotoxicity, evidenced by biochemical examinations, but without the presence of clinical signs. (c) 2006 Elsevier Ltd. All rights reserved.

Clinical and parasitological evaluation of dogs naturally infected by Leishmania (Leishmania) chagasi submitted to treatment with meglumine antimoniate

Aiming to evaluate the efficacy of the treatment of canine visceral leishmaniasis, to verify the occurrence of a possible disease relapse, and to search for the presence of the parasites after the end of the treatment, seven dogs naturally infected by Leishmania (Leishmania) chagasi were used. The dogs were subjected to a treatment with 75 mg/kg meglumine antimoniate subcutaneously every 12 h for 21 days, and followed-up for a period of 6 months. During the whole experimental period the animals wore deltamethrin collars and were kept in a screened kennel to avoid reinfection. Lymph node and bone marrow aspiration biopsy was carried out to search for the parasite at seven moments: before the treatment, 30, 60, 90, 120 150 and 180 days after the start of the treatment. After the end of the experiment all dogs were humanely euthanized. Then, spleen and liver imprints and ill vitro cultures were carried out to search for amastigote forms of the parasite. During the treatment all animals presented remission of symptoms. However, two dogs were observed to present new symptoms in the course of the experiment. At the end of the experiment, the presence of amastigote forms of the parasite was evidenced in five of the seven dogs. This enabled us to conclude that the treatment promoted clinical cure but did not eliminate the parasites completely. (c) 2006 Elsevier B.V. All rights reserved.

Clinical, histological and immunophenotypic findings in a mare with a mammary lymphoma associated with anaemia and pruritus

An 18-year-old Quarter Horse mare presented with an 18 week history of dermatological lesions characterised by recurrent urticaria and recent signs of enlarged mammary glands, pyrexia, alopecia and intense pruritus. Haematological and serum biochemical analyses revealed anaemia, leucocytosis, thrombocytopenia and hyperfibrinogenaemia. Mammary discharge was evaluated and revealed neutrophilia. Cytological examinations of fine needle aspirates from the parotid lymph nodes were normal. Common causes of anaemia were ruled out by specific tests. The initial diagnosis was mastitis and 2 weeks later the animal returned to the hospital with worsening of clinical signs, intermittent fever, intense pruritus and generalised alopecia. Blood samples were collected for haematological and serum biochemical analyses, and the mammary gland and parotid lymph nodes were biopsied. Rectal palpation revealed a large irregular mass near the left kidney with adhesions of surrounding structures. The animal died before the laboratory results were ready. This report details the clinical, histological and immunophenotypic findings of a case of large lymphoma in a mare.

Resolution of a titanium implant fracture after a recurrent trauma

Post-traumatic complications occasionally lead to tooth loss as well as the need for future implants. However, rehabilitation with endosseous osseointegrated implants does not protect the patient from the risk of suffering a new trauma. Implant fracture and the damage of the hexagon are post-traumatic complications that guide the clinician to preparing a more intricate treatment plan. The authors present a clinical case of a recurrent trauma of maxillary implant fracture. The treatment plan was to remove the implants followed by autogenous bone grafting to correct the defect. Two titanium implants were replaced, followed by connective tissue graft after allowing complete the healing process of the bone graft to occur. In the postoperative period of 6 months, satisfactory results have been shown as regards soft and hard tissues wound healing.

Relationship between Mast Cells and the Colitis with Relapse Induced by Trinitrobenzesulphonic Acid in Wistar Rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

DNA gains at 8q23.2: a potential early marker in head and neck carcinomas

Gains or amplifications involving chromosome arm 8q are one of the most recurrent chromosomal alterations in head and neck tumors. To characterize previously reported gains, we performed fluorescence in situ hybridization (FISH) using the sequences BAC RP1179E1 and 8-centromere PMJ 128 as probes. Gains and/or amplifications were detected in all 19 cases evaluated by FISH. The FISH analysis, but not G-banding, revealed homogeneously staining region in three cases. We conclude that gains of one or more genes on chromosome arm 8q may be important for the early stages of head and neck carcinomas. (C) 2003 Elsevier B.V. All rights reserved.

Decreased production of TNF-alpha by lymph node cells indicates experimental autoimmune encephalomyelitis remission in Lewis rats

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)