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Biomedical subjects

D Savić

Publications and source records attributed to D Savić.

At least 19 recordsLinked to original sources
PubMed2006

From single-objective to multiple-objective multiple-rainfall events automatic calibration of urban storm water runoff models using genetic algorithms.

The calibration of storm water runoff models is a complex task. Early attempts focused on the choice of a performance criterion function that could capture all the facets of the problem into a single-objective framework. Subsequently, the awareness that a good calibration must necessarily take into account conflicting objectives led to the adoption of more sophisticated multi-objective approaches. Only recently, the focus has shifted towards effective ways of exploiting the mounting information provided by the availability of many sets of concurrent rainfall and flow measurements. This paper revisits through a case study the transition just elucidated: the calibration of a SWMM model applied to a catchment in Singapore is tackled through a single-objective, a multi-objective and a multi-objective multiple-event (MOME) paradigm respectively. A new approach to support the latter is presented herein. It consists in formulating the problem of model calibration as a multi-objective problem with m x r objective functions, where m and r are the number of performance criteria and rainfall events respectively, that must be optimized simultaneously. Results suggest that the new MOME framework performs significantly better than the others tested on the case study presented.

Algorithms↗
PubMed2005

JP-3 gene polymorphism in a healthy population of Serbia and Montenegro.

Expansions of CTG repeats in JP-3 gene are associated with a phenotype similar to Huntington disease. These expansions are the cause of Huntington disease like-2 (HDL-2) phenotype. CTG repeats in JP-3 gene are polymorphic in healthy population. Analyses of CTG repeat polymorphism of JP-3 gene in various healthy populations could help in estimating the population at risk for developing HDL-2. CTG repeat polymorphism of JP-3 gene was analysed in healthy population of Serbia and Montenegro. Study included 198 unrelated subjects. Analyses of JP-3 locus were performed using PCR and sequencing. Six different JP-3 alleles were obtained and they were in the range of 11 to 18 CTG repeats showing a bimodal distribution, with peaks at 14 and 16. Results show that the distribution of JP-3 alleles in population of Serbia and Montenegro is consistent with distributions in other analysed populations. The absence of alleles with more then 18 CTG repeats suggests that HDL-2 is very rare in the populations of Serbia and Montenegro.

Female↗
PubMed2005

Haplotype analysis of the DM1 locus in the Serbian population.

OBJECTIVES: Analysis of the CTG-repeat number and three biallelic markers, Alu(+/-), HinfI(+/-), and TaqI(+/-), in the DMPK gene in healthy and myotonic dystrophy type 1 (DM1) Serbian individuals. Also, the consideration of haplotypes in the light of the proposed models of CTG-repeat evolution and origin of the DM1 mutation. MATERIALS AND METHODS: Markers were analyzed by PCR and haplotypes were obtained on 203 unrelated normal chromosomes and 24 unrelated DM1 chromosomes. RESULTS: A strong linkage disequilibrium was detected between the three biallelic markers alone (P <0.0001) and between distinct CTG-repeat size classes and reconstructed haplotypes. Greater than 98% of normal chromosomes contain (+++) and (- - -) haplotypes. The (+++) haplotype is the most common, while the (CTG)(9-17) are the most frequent alleles. We found a complete association of (+++) haplotype with (CTG)(> or =18) and mutated alleles. CONCLUSIONS: (CTG)(9-17)/(+++) haplotype is the ancestral haplotype and DM1 mutation occurred on (CTG)(18-35)/+++ chromosome.

Case-Control Studies↗
PubMed2005

[Comparison of clinical results of anterior cruciate ligament reconstruction using two different procedures].

During the last two decades the "golden standard" in reconstruction of anterior cruciate ligament knee was the middle third of patellar tendon, but now are more used hamstrings tendon autograft. The aim of this work was to compare our results of the artroscopic reconstruction ACL (anterior cruciate ligament) of the knee using two different technics. We were controling 60 patients within the period of two years after operation. Group A was composed of 39 patients which had reconstructed ACL done with bone-patella tendon- bone autografts, in the group B were 21 patients and at them as autographts have been used hamstring tendon. Difference between healthe and the ill knee by the Lachman's test after operation, in the group A was 2,4 mm, but in the group B was 2,2mm (p> 0,05 ). Postoperative middle value of the Lysholm and Gillquist score in the group A was 97,74, in the group B it was 96,67 (p>0,05). IKDC score results are following: Group A- mark A 32 patients (84,6%); mark B 5 (12,8%); mark C 1 (2,6%) and in the group B: mark A 17 patients (81%); mark B 3 (14,28%): mark C 1 (4,72%) (p> 0,05). Postoperative value for the Tegner and Lyscholm score activity in the A group was 8,23, in B group it was 8,81. The reconstruction of ACL with bone- patella tendon-bone grafts gave better results then the reconstruction with the hamstring tendon only according to Tegner score values. In other parameters between those two groups there was no statisticaly significant difference.

Anterior Cruciate Ligament↗
PubMed2005

Automatic calibration of urban drainage model using a novel multi-objective genetic algorithm.

In order to successfully calibrate an urban drainage model, multiple calibration criteria should be considered. This raises the issue of adopting a method for comparing different solutions (parameter sets) according to a set of objectives. Amongst the global optimization techniques that have blossomed in recent years, Multi Objective Genetic Algorithms (MOGA) have proved effective in numerous engineering applications, including sewer network modelling. Most of the techniques rely on the condition of Pareto efficiency to compare different solutions. However, as the number of criteria increases, the ratio of Pareto optimal to feasible solutions increases as well. The pitfalls are twofold: the efficiency of the genetic algorithm search worsens and decision makers are presented with an overwhelming number of equally optimal solutions. This paper proposes a new MOGA, the Preference Ordering Genetic Algorithm, which alleviates the drawbacks of conventional Pareto-based methods. The efficacy of the algorithm is demonstrated on the calibration of a physically-based, distributed sewer network model and the results are compared with those obtained by NSGA-II, a widely used MOGA.

Algorithms↗
PubMed2005

SIPSON--simulation of interaction between pipe flow and surface overland flow in networks.

The new simulation model, named SIPSON, based on the Preissmann finite difference method and the conjugate gradient method, is presented in the paper. This model simulates conditions when the hydraulic capacity of a sewer system is exceeded, pipe flow is pressurized, the water flows out from the piped system to the streets, and the inlets cannot capture all the runoff. In the mathematical model, buried structures and pipelines, together with surface channels, make a horizontally and vertically looped network involving a complex interaction of flows. In this paper, special internal boundary conditions related to equivalent inlets are discussed. Procedures are described for the simulation of manhole cover loss, basement flooding, the representation of street geometry, and the distribution of runoff hydrographs between surface and underground networks. All these procedures are built into the simulation model. Relevant issues are illustrated on a set of examples, focusing on specific parameters and comparison with field measurements of flooding of the Motilal ki Chal catchment (Indore, India). Satisfactory agreement of observed and simulated hydrographs and maximum surface flooding levels is obtained. It is concluded that the presented approach is an improvement compared to the standard "virtual reservoir" approach commonly applied in most of the models.

Disasters↗
PubMed2004

Spinocerebellar ataxia type 17 in the Yugoslav population.

OBJECTIVES: (1) Analysis of Spinocerebellar ataxia type 17 (SCA17) locus in a group of ataxic patients excluded on other known SCAs; (2) assessment of frequency distributions of SCA17 alleles in the Yugoslav population. MATERIAL AND METHODS: Study includes 115 non-related Yugoslav patients belonging to autosomal-dominant cerebellar ataxias or to sporadic idiopathic adult-onset ataxia and 115 controls. Analysis of SCA17 locus was performed using polymerase chain reaction. RESULTS: None of the analyzed patients show the presence of mutation in SCA17 locus. In the group of patients 12 different alleles in the range of 30-42 repeats were observed, while in healthy population eight alleles in the range of 30-40 repeats were detected. CONCLUSION: (1) None of 115 non-related Yugoslav ataxic patients belong to any known SCAs nor to DRPLA gene; (2) the distribution of SCA17 alleles in the Yugoslav population is consistent with the distribution in other populations and (3) the paucity of alleles with more than 39 repeats could suggest that SCA17 is very rare in the Yugoslav population.

Alleles↗
PubMed2003

SCA2 and SCA3 mutations in young-onset dopa-responsive parkinsonism.

In this study no one of our 85 patients of Serbian origin with young-onset (</= 45 years) dopa-responsive parkinsonism (YOP), previously proved negative for PARK1 and PARK2 mutations, had either spinocerebellar ataxia type 2 (SCA2) or SCA3 mutation. These data do not prove the significance of these two mutations in either sporadic or familial YOP suggestive of Parkinson's disease.

Adult↗
PubMed2003

[Transplantation in peripheral nerve injuries].

Autologous nerve grafting is the most commocommnlynly used operative technique in delayed primary, or secondary nerve repair after the peripheral nerve injuries. The aim of this procedure is to overcome nerve gaps that results from the injury itself, fibrous and elastic retraction forces, resection of the damaged parts of the nerve, position of the articulations and mobilisation of the nerve. In this study we analyse the results of operated patients with transections and lacerations of the peripheral nerves from 1979 to 2000 year. Gunshot injuries have not been analyzed in this study. The majority of the injuries were in the upper extremity (more than 87% of cases). Donor for nerve transplantation had usually been sural nerve, and only occasionally medial cutaneous nerve of the forearm was used. In about 93% of cases we used interfascicular nerve grafting, and cable nerve grafting was performed in the rest of them. Most of the grafts were 1 do 5 cm long (70% of cases). Functional recovery was achieved in more than 86% of cases, which is similar to the results of the other authors. Follow up period was minimum 2 years. We analyzed the influence of different factors on nerve recovery after the operation: patient's age, location and the extent (total or partial) of nerve injury, the length of the nerve graft, type of the nerve, timing of surgery, presence of multiple nerve injuries and associated osseal and soft tissue injuries of the upper and lower extremities.

Adolescent↗
PubMed2002

CTG repeat polymorphism in DMPK gene in healthy Yugoslav population.

OBJECTIVES: Myotonic dystrophy type 1 (DM1) is caused by large expansions of cytosine-thymine-guanine (CTG)-repeats in myotonic dystrophy protein kinase (DMPK)-gene. This gene is highly polymorphic in healthy individuals. It has been proposed that expanded alleles originated from the group of large sized normal alleles. If this is correct, one should expect a positive correlation between the frequency of large sized normal alleles and a prevalence of this disorder in a population. In this paper we determined the distribution of alleles of DMPK gene in healthy Yugoslav population. MATERIAL AND METHODS: A sample of 235 healthy individuals of Yugoslav origin have been genotyped for the alleles of DMPK locus. RESULTS: We found 22 different alleles, ranging in size from 5 to 29 repeats. Among 470 chromosomes studied, 41 chromosomes had more than 18 repeats (8.72%). CONCLUSIONS: Relatively high frequency of large sized normal alleles found in our population, suggest that prevalence of DM1 in Yugoslavia should not be different from the prevalence in other European populations.

Cytosine Nucleotides↗
PubMed2001

Is the 31 CAG repeat allele of the spinocerebellar ataxia 1 (SCA1) gene locus non-specifically associated with trinucleotide expansion diseases?

A number of human hereditary neuromuscular and neurodegenerative disorders are caused by the expansion of trinucleotide repeats within certain genes. The molecular mechanisms that underlie these expansions are not yet known. We have analyzed six trinucleotide repeat-containing loci [spinocerebellar ataxias (SCA1, SCA3, SCA8), dentatorubral-pallidoluysian atrophy (DRPLA), Huntington chorea (HD) and fragile X syndrome (FRAXA)] in myotonic dystrophy type 1 (DM1) patients (n = 52). As controls, we analyzed two groups of subjects: healthy control subjects (n =133), and a group of patients with non-triplet neuromuscular diseases (n = 68) caused by point mutations, deletions or duplications (spinal muscular atrophy, Charcot-Marie-Tooth disease, type 1A, hereditary neuropathy with liability to pressure palsies, and Duchenne and Becker muscular dystrophy). Allele frequency distributions for all tested loci were similar in these three groups with the exception of the SCA1 locus. In DM1 patients, the SCA1 allele with 31 CAG repeats account for 40.4% of all chromosomes tested, which is significantly higher than in two other groups (11.3% in healthy controls and 6.6% in the group of non-triplet diseased patients; P < 0.001, Fisher's exact test). This is consistent with our previous findings in HD patients. The absence of this association in non-triplet diseases as well as in healthy controls could indicate a possible role of this SCA1 allele with 31 repeats in triplet diseases. Here we discuss a possible role of the SCA1 region in pathological trinucleotide repeat expansions.

Alleles↗
PubMed1996

Oxime-induced reactivation of acetylcholinesterase inhibited by phosphoramidates.

The reaction of human erythrocyte acetylcholinesterase (AChE) with a set of structurally related phosphoramidates was studied in order to investigate the properties of phosphorylated enzyme and the effects of 4 oximes PAM-2, TMB-4, HI-6 and BDB-106 on the reactivation of inhibited AChE. Second-order rate constant of the phosphorylation reaction of the compounds towards the active site of AChE range between 5.0 x 10(2) and 4.9 x 10(6) M-1min-1 and their inhibitory power (I50) was from 7.3 x 10(-5) to 5.7 x 10(-9) M for 20 min incubation at 37 degrees C. The oximes used were weak reactivators of inhibited AChE except for (C4H9O)(NH2)P(O)DCP (DCP, -O-2,5-dichlorphenyl group) and (C6H13O)(NH2)P(O)SCH3 where we have obtained good reactivation. Imidazole oxime BDB-106 proved to be a potent reactivator of tabun-inhibited AChE.

Acetylcholinesterase↗
PubMed1996

Enteroaggregative Escherichia coli associated with an outbreak of diarrhoea in a neonatal nursery ward.

Over a 9-day period in February 1995, 16 newborn babies (age range 2-11 days) and 3 infants (24, 47 and 180 days of age) in a neonatal nursery ward developed diarrhoea accompanied by pyrexia and weight loss. Known enteropathogens were not detected in their stools but Escherichia coli displaying aggregative adherence to HEp-2 cells (enteroaggregative E. coli) were found in 12 (63%) ill infants and in none of 5 well neonates (P = 0.02). The illness lasted 3-9 days (mean 5.2) in 16 babies, whereas in 3 neonates it showed a protracted course of 18-20 days. The source of infection and the mode of transmission remained unclear. The outbreak isolates manifested properties common in this new group of diarrhoeagenic E. coli: mannose-resistant haemagglutination, haemolysis on blood agar, and clump formation in liquid culture medium. They belonged to the O4 E. coli serogroup and expressed multiple antibiotic resistance.

Bacterial Adhesion↗
PubMed1995

[Etiopathogenic, diagnostic and therapeutic aspects of stress fractures].

Stress fractures occur with strenuous activity and represent a unique and relatively rare traumatic entity. Their diagnosis is difficult and therapy accompanied with specific problems. The purpose of the presented study is to explain basic characteristics of stress fractures and to approximate possibility of diagnosis and treatment better. Out of 26 fractures, 22 (84.62%) were nondisplaced and managed by bed rest, non-weight bearing or plaster of Paris immobilization for eight to ten weeks. On the other hand, four primarily displaced fractures (15.38%) were successfully treated with rigid internal fixation. Four conservatively managed patients (18.18%), two with fractures of the tibia and two with fractures of the femoral neck, attained a secondary angulation and pseudoarthrosis of the fracture site and, for these reasons, recorded injuries demanded a compensatory surgery management. It is suggested that in case of suspectability of stress fractures it is beneficial to use, parallel to native radiographic study, the bone scan imaging techniques which in the earlier phase of the disease establishes the diagnosis. Treatment of the stress fractures should be, as a rule, conservative. Moreover, "fatigue" fractures of the tibia and femoral neck ask for more continuous observations and a serious access. If non weightbearing regiment and immobilization do not decrease the difficulties; and fracture patterns progress, or if fracture becomes displaced because of delayed diagnosis, open reduction and rigid internal fixation should be done without delay.

Adolescent↗
PubMed1995

[Fractures of the spine in patients with ankylosing spondylitis].

Eight patients with spine fractures in chronic ankylosing spondylitis have been analyzed. The purpose of this article is to determine possibilities of spine injuries accompanied with this specific rheumatic disease and to show difficulties in diagnosis and problems in treatment. Ankylosing spondylitis affects spine in the way that it ossifficate ligaments, synovial joints and other soft tissue structures. Fractures that occur through these areas involve both bones and ligaments, producing an unstable condition, similar to a shearing type of classic spine injuries. The radiologic diagnosis of these injuries is difficult because the bone is frequently osteoporotic and displacement is of minor degree. In this study, 41.67% of the patients were not diagnosed initially and 16.67% were, for this reason, deteriorated neurologically. Therefore, patients known to have ankylosing spondylitis should be examined regarding the possibility of a fracture, and if pains persist after an injury, they should be thoroughly investigated radiologically to rule out a potentially serious problem. Reduction of the displacement and adequate stabilization, preferably by surgery, should be achieved whenever possible.

Adult↗