Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 54
Filter
1.
Comput Methods Biomech Biomed Engin ; 26(12): 1443-1451, 2023 Sep.
Article in English | MEDLINE | ID: mdl-36093767

ABSTRACT

This study aims to integrate an open-source software capable of estimating hydrodynamic forces solely from kinematic data with a full-body biomechanical model of the human body to enable inverse dynamic analyses of swimmers. To demonstrate the methodology, intersegmental forces and joint torques of the lower limbs were computed for a six-beat front crawl swimming motion, acquired at LABIOMEP-UP. The hydrodynamic forces obtained compare well with existing numerical literature. The intersegmental forces and joint torques obtained increase from distal to proximal joints. Overall, the results are consistent with the limited literature on swimming biomechanics, which provides confidence in the presented methodology.


Subject(s)
Hydrodynamics , Swimming , Humans , Motion , Biomechanical Phenomena , Lower Extremity
3.
BMC Genomics ; 21(1): 558, 2020 Aug 14.
Article in English | MEDLINE | ID: mdl-32795250

ABSTRACT

BACKGROUND: Rainbow trout is a significant fish farming species under temperate climates. Female reproduction traits play an important role in the economy of breeding companies with the sale of fertilized eggs. The objectives of this study are threefold: to estimate the genetic parameters of female reproduction traits, to determine the genetic architecture of these traits by the identification of quantitative trait loci (QTL), and to assess the expected efficiency of a pedigree-based selection (BLUP) or genomic selection for these traits. RESULTS: A pedigreed population of 1343 trout were genotyped for 57,000 SNP markers and phenotyped for seven traits at 2 years of age: spawning date, female body weight before and after spawning, the spawn weight and the egg number of the spawn, the egg average weight and average diameter. Genetic parameters were estimated in multi-trait linear animal models. Heritability estimates were moderate, varying from 0.27 to 0.44. The female body weight was not genetically correlated to any of the reproduction traits. Spawn weight showed strong and favourable genetic correlation with the number of eggs in the spawn and individual egg size traits, but the egg number was uncorrelated to the egg size traits. The genome-wide association studies showed that all traits were very polygenic since less than 10% of the genetic variance was explained by the cumulative effects of the QTLs: for any trait, only 2 to 4 QTLs were detected that explained in-between 1 and 3% of the genetic variance. Genomic selection based on a reference population of only one thousand individuals related to candidates would improve the efficiency of BLUP selection from 16 to 37% depending on traits. CONCLUSIONS: Our genetic parameter estimates made unlikely the hypothesis that selection for growth could induce any indirect improvement for female reproduction traits. It is thus important to consider direct selection for spawn weight for improving egg production traits in rainbow trout breeding programs. Due to the low proportion of genetic variance explained by the few QTLs detected for each reproduction traits, marker assisted selection cannot be effective. However genomic selection would allow significant gains of accuracy compared to pedigree-based selection.


Subject(s)
Oncorhynchus mykiss , Animals , Female , Genome-Wide Association Study , Genomics , Oncorhynchus mykiss/genetics , Phenotype , Polymorphism, Single Nucleotide , Reproduction/genetics , Selection, Genetic
4.
Anim Genet ; 50(3): 293-297, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30883847

ABSTRACT

In rainbow trout farming, Flavobacterium psychrophilum, the causative agent of bacterial cold water disease, is responsible for important economic losses. Resistance to F. psychrophilum is heritable, and several quantitative trait loci (QTL) with moderate effects have been detected, opening up promising perspectives for the genetic improvement of resistance. In most studies however, resistance to F. psychrophilum was assessed in experimental infectious challenges using injection as the infection route, which is not representative of natural infection. Indeed, injection bypasses external barriers, such as mucus and skin, that likely play a protective role against the infection. In this study, we aimed at describing the genetic architecture of the resistance to F. psychrophilum after a natural disease outbreak. In a 2000-fish cohort, reared on a French farm, 720 fish were sampled and genotyped using the medium-throughput Axiom™ Trout Genotyping Array. Overall mortality at the end of the outbreak was 25%. Genome-wide association studies were performed under two different models for time to death measured on 706 fish with validated genotypes for 30 060 SNPs. This study confirms the polygenic inheritance of resistance to F. psychrophilum with a few QTL with moderate effects and a large polygenic background, the heritability of the trait being estimated at 0.34. Two new chromosome-wide significant QTL and three suggestive QTL were detected, each of them explaining between 1% and 4% of genetic variance.


Subject(s)
Disease Outbreaks/veterinary , Disease Resistance , Flavobacteriaceae Infections/veterinary , Oncorhynchus mykiss , Poultry Diseases/epidemiology , Animals , Flavobacteriaceae Infections/epidemiology , Flavobacteriaceae Infections/genetics , Flavobacteriaceae Infections/immunology , Flavobacterium/physiology , France/epidemiology , Poultry Diseases/genetics , Poultry Diseases/immunology , Quantitative Trait Loci
5.
J Helminthol ; 93(5): 539-547, 2019 Sep.
Article in English | MEDLINE | ID: mdl-30149822

ABSTRACT

Androgens have been shown to exert a cysticidal effect upon Taenia crassiceps, an experimental model of cysticercosis. To further inquire into this matter, the Taenia crassiceps model was used to evaluate the expression of several proteins after testosterone (T4) and dihydrotestosterone (DHT) in vitro treatment. Under 2-D proteomic maps, parasite extracts were resolved into approximately 130 proteins distributed in a molecular weight range of 10-250 kDa and isoelectrical point range of 3-10. The resultant proteomic pattern was analysed, and significant changes were observed in response to T4 and DHT. Based on our experience with electrophoretic patterns and proteomic maps of cytoskeletal proteins, alteration in the expression of isoforms of actin, tubulin and paramyosin and of other proteins was assessed. Considering that androgens may exert their biological activity in taeniids through the non-specific progesterone receptor membrane component (PGRMC), we harnessed bioinformatics to propose the identity of androgen-regulated proteins and establish their hypothetical physiological role in the parasites. These analyses yield a possible explanation of how androgens exert their cysticidal effects through changes in the expression of proteins involved in cytoskeletal rearrangement, dynamic vesicular traffic and transduction of intracellular signals.


Subject(s)
Androgens/pharmacology , Cell Death , Proteome , Taenia/drug effects , Taenia/physiology , Actins/genetics , Animals , Computational Biology , Cysticercosis/pathology , Cysticercus/drug effects , Cysticercus/physiology , Cytoskeleton/drug effects , Cytoskeleton/genetics , Dihydrotestosterone/pharmacology , Female , Mice , Mice, Inbred BALB C , Receptors, Progesterone/genetics , Testosterone/pharmacology , Tropomyosin/genetics , Tubulin/genetics
6.
Stem Cells Int ; 2018: 2891957, 2018.
Article in English | MEDLINE | ID: mdl-30402108

ABSTRACT

An understanding of the cytoskeleton's importance in stem cells is essential for their manipulation and further clinical application. The cytoskeleton is crucial in stem cell biology and depends on physical and chemicals signals to define its structure. Additionally, cell culture conditions will be important in the proper maintenance of stemness, lineage commitment, and differentiation. This review focuses on the following areas: the role of the actin cytoskeleton of stem cells during differentiation, the significance of cellular morphology, signaling pathways involved in cytoskeletal rearrangement in stem cells, and the mechanobiology and mechanotransduction processes implicated in the interactions of stem cells with different surfaces of biomaterials, such as nanotopography, which is a physical cue influencing the differentiation of stem cells. Also, cancer stem cells are included since it is necessary to understand the role of their mechanical properties to develop new strategies to treat cancer. In this context, to study the stem cells requires integrated disciplines, including molecular and cellular biology, chemistry, physics, and immunology, as well as mechanobiology. Finally, since one of the purposes of studying stem cells is for their application in regenerative medicine, the deepest understanding is necessary in order to establish safety protocols and effective cell-based therapies.

7.
Med Eng Phys ; 38(9): 969-77, 2016 09.
Article in English | MEDLINE | ID: mdl-27381499

ABSTRACT

Kinematically unconstrained biomechanical models of the glenohumeral (GH) joint are needed to study the GH joint function, especially the mechanisms of joint stability. The purpose of this study is to develop a large-scale multibody model of the upper limb that simulates the 6 degrees of freedom (DOF) of the GH joint and to propose a novel inverse dynamics procedure that allows the evaluation of not only the muscle and joint reaction forces of the upper limb but also the GH joint translations. The biomechanical model developed is composed of 7 rigid bodies, constrained by 6 anatomical joints, and acted upon by 21 muscles. The GH joint is described as a spherical joint with clearance. Assuming that the GH joint translates according to the muscle load distribution, the redundant muscle load sharing problem is formulated considering as design variables the 3 translational coordinates associated with the GH joint translations, the joint reaction forces associated with the remaining kinematic constraints, and the muscle activations. For the abduction motion in the frontal plane analysed, the muscle and joint reaction forces estimated by the new biomechanical model proposed are similar to those estimated by a model in which the GH joint is modeled as an ideal spherical joint. Even though this result supports the assumption of an ideal GH joint to study the muscle load sharing problem, only a 6 DOF model of the GH joint, as the one proposed here, provides information regarding the joint translations. In this study, the biomechanical model developed predicts an initial upward and posterior migration of the humeral head, followed by an inferior and anterior movement, which is in good agreement with the literature.


Subject(s)
Mechanical Phenomena , Models, Biological , Shoulder Joint , Shoulder , Biomechanical Phenomena , Humans , Movement , Muscle, Skeletal/physiology , Range of Motion, Articular , Shoulder/physiology , Shoulder Joint/physiology
8.
Article in English | MEDLINE | ID: mdl-26325481

ABSTRACT

Musculoskeletal models and forward dynamics simulations of human movement often include foot-ground interactions, with the foot-ground contact forces often determined using a constitutive model that depends on material properties and contact kinematics. When using soft constraints to model the foot-ground interactions, the kinematics of the minimum distance between the foot and planar ground needs to be computed. Due to their geometric simplicity, a considerable number of studies have used point-plane elements to represent these interacting bodies, but few studies have provided comparisons between point contact elements and other geometrically based analytical solutions. The objective of this work was to develop a more general-purpose superellipsoid-plane contact model that can be used to determine the three-dimensional foot-ground contact forces. As an example application, the model was used in a forward dynamics simulation of human walking. Simulation results and execution times were compared with a point-like viscoelastic contact model. Both models produced realistic ground reaction forces and kinematics with similar computational efficiency. However, solving the equations of motion with the surface contact model was found to be more efficient (~18% faster), and on average numerically ~37% less stiff. The superellipsoid-plane elements are also more versatile than point-like elements in that they allow for volumetric contact during three-dimensional motions (e.g. rotating, rolling, and sliding). In addition, the superellipsoid-plane element is geometrically accurate and easily integrated within multibody simulation code. These advantages make the use of superellipsoid-plane contact models in musculoskeletal simulations an appealing alternative to point-like elements.


Subject(s)
Biophysical Phenomena , Computer Simulation , Foot/physiology , Gait/physiology , Models, Biological , Adult , Biomechanical Phenomena , Female , Humans , Imaging, Three-Dimensional , Male , Models, Anatomic , Musculoskeletal System/anatomy & histology
9.
J Biomech ; 48(12): 3242-51, 2015 Sep 18.
Article in English | MEDLINE | ID: mdl-26206550

ABSTRACT

The reverse shoulder prosthesis aims to restore the stability and function of pathological shoulders, but the biomechanical aspects of the geometrical changes induced by the implant are yet to be fully understood. Considering a large-scale musculoskeletal model of the upper limb, the aim of this study is to evaluate how the Delta reverse shoulder prosthesis influences the biomechanical behavior of the shoulder joint. In this study, the kinematic data of an unloaded abduction in the frontal plane and an unloaded forward flexion in the sagittal plane were experimentally acquired through video-imaging for a control group, composed of 10 healthy shoulders, and a reverse shoulder group, composed of 3 reverse shoulders. Synchronously, the EMG data of 7 superficial muscles were also collected. The muscle force sharing problem was solved through the minimization of the metabolic energy consumption. The evaluation of the shoulder kinematics shows an increase in the lateral rotation of the scapula in the reverse shoulder group, and an increase in the contribution of the scapulothoracic joint to the shoulder joint. Regarding the muscle force sharing problem, the musculoskeletal model estimates an increased activity of the deltoid, teres minor, clavicular fibers of the pectoralis major, and coracobrachialis muscles in the reverse shoulder group. The comparison between the muscle forces predicted and the EMG data acquired revealed a good correlation, which provides further confidence in the model. Overall, the shoulder joint reaction force was lower in the reverse shoulder group than in the control group.


Subject(s)
Joint Prosthesis , Shoulder Joint/physiology , Adult , Aged , Aged, 80 and over , Biomechanical Phenomena , Clavicle/physiology , Computer Simulation , Deltoid Muscle/physiology , Female , Humans , Male , Models, Biological , Muscle Contraction , Muscle Strength , Pectoralis Muscles/physiology , Range of Motion, Articular/physiology , Rotator Cuff/physiology , Scapula/physiology , Shoulder/physiology , Young Adult
10.
J Biomech Eng ; 135(11): 111005, 2013 Nov.
Article in English | MEDLINE | ID: mdl-24008920

ABSTRACT

The reverse shoulder replacement, recommended for the treatment of several shoulder pathologies such as cuff tear arthropathy and fractures in elderly people, changes the biomechanics of the shoulder when compared to the normal anatomy. Although several musculoskeletal models of the upper limb have been presented to study the shoulder joint, only a few of them focus on the biomechanics of the reverse shoulder. This work presents a biomechanical model of the upper limb, including a reverse shoulder prosthesis, to evaluate the impact of the variation of the joint geometry and position on the biomechanical function of the shoulder. The biomechanical model of the reverse shoulder is based on a musculoskeletal model of the upper limb, which is modified to account for the properties of the DELTA® reverse prosthesis. Considering two biomechanical models, which simulate the anatomical and reverse shoulder joints, the changes in muscle lengths, muscle moment arms, and muscle and joint reaction forces are evaluated. The muscle force sharing problem is solved for motions of unloaded abduction in the coronal plane and unloaded anterior flexion in the sagittal plane, acquired using video-imaging, through the minimization of an objective function related to muscle metabolic energy consumption. After the replacement of the shoulder joint, significant changes in the length of the pectoralis major, latissimus dorsi, deltoid, teres major, teres minor, coracobrachialis, and biceps brachii muscles are observed for a reference position considered for the upper limb. The shortening of the teres major and teres minor is the most critical since they become unable to produce active force in this position. Substantial changes of muscle moment arms are also observed, which are consistent with the literature. As expected, there is a significant increase of the deltoid moment arms and more fibers are able to elevate the arm. The solutions to the muscle force sharing problem support the biomechanical advantages attributed to the reverse shoulder design and show an increase in activity from the deltoid, teres minor, and coracobrachialis muscles. The glenohumeral joint reaction forces estimated for the reverse shoulder are up to 15% lower than those in the normal shoulder anatomy. The data presented here complements previous publications, which, all together, allow researchers to build a biomechanical model of the upper limb including a reverse shoulder prosthesis.


Subject(s)
Mechanical Phenomena , Prostheses and Implants , Shoulder , Biomechanical Phenomena , Joints , Models, Biological , Muscles
11.
Oral Dis ; 17 Suppl 1: 95-8, 2011 Apr.
Article in English | MEDLINE | ID: mdl-21382142

ABSTRACT

OBJECTIVES: The aim of this preliminary study was to investigate postgraduate Oral Medicine training worldwide and to begin to identify minimum requirements and/or core content for an International Oral Medicine curriculum. MATERIALS AND METHODS: Countries where there was believed to be postgraduate training in Oral Medicine were identified by the working group. Standardized emails were sent inviting participants to complete an online survey regarding the scope of postgraduate training in Oral Medicine in their respective countries. RESULTS: We received 69 total responses from 37 countries. Of these, 22 countries self-identified as having postgraduate Oral Medicine as a distinct field of study, and they served as the study group. While there is currently considerable variation among Oral Medicine postgraduate training parameters, there is considerable congruency in clinical content of the Oral Medicine syllabi. For example, all of the training programs responded that they did evaluate competence in diagnosis and management of oral mucosal disease. CONCLUSIONS: This preliminary study provides the first evidence regarding international Oral Medicine postgraduate training, from which recommendations for an international core curriculum could be initiated. It is through such an initiative that a universal clinical core syllabus in postgraduate Oral Medicine training may be more feasible.


Subject(s)
Education, Dental, Graduate , Oral Medicine/education , Clinical Competence , Curriculum/standards , Diagnosis, Oral/education , Education, Dental, Graduate/classification , Education, Dental, Graduate/standards , Facial Pain/diagnosis , Facial Pain/therapy , Humans , International Cooperation , Mouth Diseases/diagnosis , Mouth Diseases/therapy , Pathology, Oral/education , Pharmacology/education , Radiology/education , Radiology, Interventional/education , Salivary Gland Diseases/diagnosis , Salivary Gland Diseases/therapy , Specialties, Dental/classification , Specialties, Dental/education , Specialties, Dental/standards , Surveys and Questionnaires
12.
Rev Neurol ; 44(7): 404-10, 2007.
Article in Spanish | MEDLINE | ID: mdl-17420966

ABSTRACT

INTRODUCTION: When dealing with patients in coma, it can be very useful to have early access to objective tests that provide information about their clinical status and can help to establish a prognosis for survival and functional recovery. The value of evoked potentials (EP) in such cases is already well known, although only techniques that assess the neurological status have been used. AIM: To determine the usefulness of different types of evoked potentials as a means of reaching a short and medium term prognosis for survival and functional recovery in patients in coma as a result of traumatic brain injury (TBI). PATIENTS AND METHODS: Our study involved patients with an admission Glasgow coma score of 8 or below due to severe TBI. During the first 24 hours the following tests were carried out on patients: somatosensory EP (SSEP), brainstem auditory EP, visual EP (VEP) obtained using stimulation goggles and mismatch negativity, as well as an imaging test (computerised axial tomography). The tests were repeated at one week and one month, and each patient was evaluated by means of the Glasgow scale and the Karnofsky scale. RESULTS: We studied 22 patients (mean age: 39.95 years; interval: 15-84 years), 20 of them were males. The highest number of deaths occurred during the first week. There was a strong correlation between survival and the results from the SSEP and VEP. CONCLUSIONS: SSEP and VEP performed on admission were a valuable aid for reaching a short and medium term prognosis for survival of patients in coma due to TBI, although they were not effective in evaluating a prognosis for functional recovery.


Subject(s)
Brain Injuries , Evoked Potentials/physiology , Adolescent , Adult , Aged , Aged, 80 and over , Brain Injuries/diagnosis , Brain Injuries/pathology , Brain Injuries/physiopathology , Brain Injuries/rehabilitation , Coma , Humans , Male , Middle Aged , Prognosis , Recovery of Function , Survival Rate , Treatment Outcome
13.
Rev. neurol. (Ed. impr.) ; 44(7): 404-410, 1 abr,. 2007. ilus, tab
Article in Es | IBECS | ID: ibc-054566

ABSTRACT

Introducción. En los pacientes en coma es útil disponer desde un primer momento de pruebas objetivas que nos informen del estado clínico y nos sirvan de ayuda para establecer un pronóstico vital y funcional. El valor de los potenciales evocados (PE) en estos casos es ya conocido, aunque la mayoría de los estudios se centran sólo en algunos tipos de potenciales, valorando únicamente el estado neurológico en ese momento. Objetivo. Determinar el valor pronóstico vital y funcional a corto y medio plazo de los distintos tipos de potenciales evocados en pacientes en coma secundario a traumatismo craneoencefálico (TCE). Pacientes y métodos. Pacientes con un Glasgow de ingreso igual o inferior a 8 debido a un TCE grave. En las primeras 24 horas se les realizaron PE somatosensitivos (PESS) de nervio mediano, PE auditivos de tronco, PE visuales (PEV) obtenidos con estimulador goggles y mismatch negativity, además de una prueba de imagen (tomografía axial computarizada). Las pruebas se repitieron a la semana y al mes, y se valoró a cada paciente mediante la escala de Glasgow y la escala de Karnofsky. Resultados. Estudiamos 22 pacientes (media: 39,95 años; intervalo: 15-84 años), 20 de ellos varones. Durante la primera semana se produjo el mayor número de fallecimientos. Existió una fuerte correlación entre la supervivencia y los resultados obtenidos con PESS y PEV. Conclusión. Los PESS y PEV realizados al ingreso son de gran utilidad para la valoración pronóstica vital a corto y medio plazo del paciente en coma por TCE, sin llegar a mostrar eficacia en la valoración pronóstica funcional


Introduction. When dealing with patients in coma, it can be very useful to have early access to objective tests that provide information about their clinical status and can help to establish a prognosis for survival and functional recovery. The value of evoked potentials (EP) in such cases is already well known, although only techniques that assess the neurological status have been used. Aim. To determine the usefulness of different types of evoked potentials as a means of reaching a short and medium term prognosis for survival and functional recovery in patients in coma as a result of traumatic brain injury (TBI). Patients and methods. Our study involved patients with an admission Glasgow coma score of 8 or below due to severe TBI. During the first 24 hours the following tests were carried out on patients: somatosensory EP (SSEP), brainstem auditory EP, visual EP (VEP) obtained using stimulation goggles and mismatch negativity, as well as an imaging test (computerised axial tomography). The tests were repeated at one week and one month, and each patient was evaluated by means of the Glasgow scale and the Karnofsky scale. Results.We studied 22 patients (mean age: 39.95 years; interval: 15-84 years), 20 of them were males. The highest number of deaths occurred during the first week. There was a strong correlation between survival and the results from the SSEP and VEP. Conclusions. SSEP and VEP performed on admission were a valuable aid for reaching a short and medium term prognosis for survival of patients in coma due to TBI, although they were not effective in evaluating a prognosis for functional recovery


Subject(s)
Male , Female , Adolescent , Adult , Middle Aged , Aged , Aged, 80 and over , Humans , Coma, Post-Head Injury , Evoked Potentials , Glasgow Coma Scale , Prospective Studies , Prognosis , Follow-Up Studies , Predictive Value of Tests , Severity of Illness Index
14.
Cell Biol Int ; 30(7): 598-602, 2006 Jul.
Article in English | MEDLINE | ID: mdl-16733094

ABSTRACT

Type II myosins are highly conserved proteins, though differences have been observed among organisms, mainly in the filamentous region. Myosin isoforms have been identified in Taenia solium, a helminth parasite of public health importance in many developing countries. These isoforms are probably associated with the physiological requirements of each developmental stage of the parasite. In this paper we extend the characterization of myosin to several other Taenia species. Type II myosins were purified from the larvae (cysticerci) of Taenia solium, T. taeniaeformis and T. crassiceps and the adult stages of T. solium, T. taeniaeformis and T. saginata. Rabbit polyclonal antibodies against some of these myosins were specific at high dilutions but cross-reacted at low dilutions. ATPase activity was evaluated and kinetic values were calculated for each myosin. Homologous actin-myosin interactions increased both the affinity of myosin for ATP and the hydrolysis rate. The results indicate immunological and biochemical differences among taeniid myosins. This variability suggests that different isoforms are found not only in different taeniid species but also at different developmental stages. Further characterization of myosin isoforms should include determination of their amino acid composition.


Subject(s)
Myosin Type II/immunology , Myosin Type II/metabolism , Animals , Enzyme-Linked Immunosorbent Assay , Myosin Type II/isolation & purification , Myosins/metabolism , Peptide Mapping , Protein Isoforms/analysis , Taenia
15.
Parasitology ; 127(Pt 5): 457-73, 2003 Nov.
Article in English | MEDLINE | ID: mdl-14653535

ABSTRACT

The liver fluke, Fasciola hepatica relies on a well-developed muscular system, not only for attachment, but for many aspects of its biology. Despite this, little is known about the system beyond the gross organization of the main somatic muscle layers. In the present study, a range of techniques have been applied to F. hepatica in order to understand more about various aspects of muscle organization, biochemistry (in terms of muscle proteins) and identity of isolated muscle fibres. Scanning electron microscopy has provided a direct visualization in situ of the somatic muscle layers and the organization of the muscle fibres within the ventral sucker. The muscle bundles contributing to the main somatic muscle layers are made up of up to 10 individual muscle fibres. Phalloidin staining for actin, in conjunction with confocal microscopy, confirmed the presence of 2 main somatic muscle layers (outer circular, inner longitudinal), beneath which lies a third layer of oblique muscle fibres. The use of propidium iodide in combination with phalloidin staining for actin demonstrated that the cell bodies associated with the 2 main somatic muscle layers are situated beneath the longitudinal muscle layer and are connected to their respective muscle fibres by short cytoplasmic processes. Myosin immunoreactivity was demonstrated in the somatic muscle layers and in the muscle layers surrounding various organ systems within the fluke. Double labelling for actin and myosin confirmed the co-localization of the 2 muscle proteins in the muscle fibres of the ventral sucker. Muscle fibres from the somatic muscle layers and the ventral sucker have been isolated and images obtained with phase-contrast microscopy and scanning electron microscopy. The muscle fibres contain actin and myosin, but lack a nucleus, the connection with the cell body having been broken during the isolation procedure.


Subject(s)
Fasciola hepatica/ultrastructure , Muscle Fibers, Skeletal/ultrastructure , Actins/physiology , Animals , Blotting, Western , Fasciola hepatica/physiology , Microscopy, Confocal , Microscopy, Electron, Scanning , Microscopy, Fluorescence , Microscopy, Phase-Contrast , Muscle Fibers, Skeletal/physiology , Muscles/physiology , Muscles/ultrastructure , Myosins/physiology
16.
J Am Dent Assoc ; 132(10): 1425-32, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11680359

ABSTRACT

BACKGROUND: The prevalence of diabetes mellitus, or DM, in the United States is increasing steadily. The increasing longevity of the American population and more effective diagnostic protocols mean that the dental practitioner will be treating an increasing number of patients with the disease. METHODS: The authors present relevant information about DM, including a recently revised nomenclature system, pathophysiology, complications, new diagnostic criteria, medical and dental management considerations, and associated oral conditions. CONCLUSIONS: There are many important medical and dental management issues that dentists should consider when treating patients with DM. CLINICAL IMPLICATIONS: The information presented in this report should help general dentists deliver optimum treatment to patients with DM.


Subject(s)
Dental Care for Chronically Ill , Diabetes Mellitus , Burning Mouth Syndrome/etiology , Dental Caries/etiology , Diabetes Complications , Diabetes Mellitus/classification , Diabetes Mellitus/drug therapy , Diabetes Mellitus/physiopathology , Diet , Humans , Hypoglycemia/etiology , Insulin/adverse effects , Insulin/metabolism , Lichen Planus, Oral/etiology , Mycoses/etiology , Oral Ulcer/etiology , Periodontal Diseases/etiology , Salivary Gland Diseases/etiology , Terminology as Topic
17.
J Biomech ; 34(9): 1217-21, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11506793

ABSTRACT

The inverse dynamic analysis procedures used in the study of the human gait require that the kinematics of the supporting biomechanical model is known beforehand. The first step to obtain the kinematic data is the reconstruction of human spatial motion, i.e., the evaluation of the anatomic points positions that enables to uniquely define the position of all anatomical segments. In photogrammetry, the projection of each anatomical point is described by two linear equations relating its three spatial coordinates with the two coordinates of the projected point. The need for the image of two cameras arises from the fact that three equations are necessary to find the original spatial position of the anatomical point. It is shown here that the kinematic constraint equations associated with a biomechanical model can be used as the extra set of equations required for the reconstruction process, instead of the equations associated with the second camera. With this methodology, the system of equations arising from the point projections and biomechanical model kinematic constraints are solved simultaneously. Since the system of equations has multiple solutions for each image, a strategy based on the minimization of the cost function associated to the smoothness of the reconstructed motion is devised, leading to an automated computer procedure enabling a unique reconstruction.


Subject(s)
Gait/physiology , Image Processing, Computer-Assisted/methods , Models, Biological , Motion , Photography , Biomechanical Phenomena , Humans
18.
Clin Diagn Lab Immunol ; 8(4): 768-71, 2001 Jul.
Article in English | MEDLINE | ID: mdl-11427424

ABSTRACT

Cholera is caused only by O1 and O139 Vibrio cholerae strains. For diagnosis, 3 working days are needed for bacterial isolation from human feces and for biochemical characterization. Here we describe the purification of bacterial outer membrane proteins (OMP) from V. cholerae O1 Ogawa, O1 Inaba, and O139 strains, as well as the production of specific antisera and their use for fecal Vibrio antigen detection. Anti-OMP antisera showed very high reactivity and specificity by enzyme-linked immunosorbent assay (ELISA) and dot-ELISA. An inmunodiagnostic assay for V. cholerae detection was developed; this assay avoids preenrichment and costly equipment and can be used for epidemiological surveillance and clinical diagnosis of cases, considering that prompt and specific identification of bacteria is mandatory in cholera.


Subject(s)
Antibodies, Bacterial/immunology , Antigens, Bacterial/immunology , Bacterial Outer Membrane Proteins/immunology , Cholera/microbiology , Vibrio cholerae/classification , Animals , Antibodies, Bacterial/biosynthesis , Cholera/blood , Cholera/diagnosis , Cholera/immunology , Enzyme-Linked Immunosorbent Assay/methods , Humans , Rabbits , Vibrio cholerae/immunology , Vibrio cholerae/isolation & purification
19.
Hum Mov Sci ; 20(6): 829-51, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11792442

ABSTRACT

The value of the results of the inverse dynamic analysis procedures used in the study of human tasks is dependent on the quality of the kinematic and kinetic data supplied to the biomechanical model that supports it. The kinematic data, containing the position, velocity and acceleration of all anatomical segments of the biomechanical model, result from the reconstruction of human spatial motion by means of the evaluation of the anatomic points positions that enable to uniquely define the position of all anatomical segments. Furthermore, the motion data must be kinematically consistent with the structure of the biomechanical model used in the analysis. The traditional photogrammetric methodologies used for the spatial reconstruction of the human motion require images of two or more calibrated and synchronized cameras. This is due to the fact that the projection of each anatomical point is described by two linear equations relating its three spatial coordinates with the two coordinates of the projected point. The need for the image of another camera arises from the fact that a third equation is necessary to find the original spatial position of the anatomical point. The methodology proposed here substitutes the projection equations of the second camera with the kinematic constraint equations associated with a biomechanical model in the motion reconstruction process. In the formulation the system of equations arising from the point projections and biomechanical model kinematic constraints, representing the constant length of the anatomical segments, are solved simultaneously. Because the system of equations has multiple solutions for each image, a strategy based on the minimization of a cost function associated to the smoothness of the reconstructed motion is devised. It is shown how the process is implemented computationally avoiding any operator intervention during the motion reconstruction for a given time period. This leads to an automated computer procedure that ensures the uniqueness of the reconstructed motion. The result of the reconstruction process is a set of data that is kinematically consistent with the biomechanical model used. Through applications of the proposed methodology to several sports exercises its benefits and shortcomings are discussed.


Subject(s)
Models, Statistical , Movement/physiology , Spatial Behavior , Biomechanical Phenomena , Humans
20.
Trans R Soc Trop Med Hyg ; 94(1): 85-9, 2000.
Article in English | MEDLINE | ID: mdl-10748908

ABSTRACT

An intervention study with mass treatment against taeniasis to prevent neurocysticercosis due to Taenia solium in a rural community in Mexico was performed in 1991-96. Information and biological samples were obtained at the beginning of the study, at 6 months and at 42 months after mass treatment with praziquantel at a single dose of 5 mg/kg. Prevalence rates of taeniasis were measured by the detection of Taenia coproantigens and Taenia eggs in faeces; neurocysticercosis was suggested by clinical data and by serum antibodies in humans and also in swine. A reduction of 53% after 6 months and of 56% after 42 months for human taeniasis was seen after treatment. Late-onset general seizures decreased 70%. Anti-cysticercus antibodies in the human population were reduced by 75% after 42 months. Antibodies in pigs also showed a significant reduction of 55% after 6 months. In conclusion, an impact of mass chemotherapy against taeniasis to control cysticercosis in the short and long term was demonstrated. Praziquantel for tapeworm treatment should not be given at doses lower than 10 mg/kg. Late-onset convulsive crisis and specific antibodies are good indicators of neurocysticercosis and of exposure to the parasite, respectively.


Subject(s)
Anthelmintics/therapeutic use , Neurocysticercosis/prevention & control , Praziquantel/therapeutic use , Taeniasis/drug therapy , Zoonoses , Adolescent , Adult , Aged , Animals , Child , Child, Preschool , Female , Humans , Male , Mexico/epidemiology , Middle Aged , Prevalence , Swine , Swine Diseases/epidemiology , Swine Diseases/transmission
SELECTION OF CITATIONS
SEARCH DETAIL
...