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1.
Sci Justice ; 58(4): 264-270, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29895458

RESUMO

Recent advances in nanotechnology applied in forensic sciences have contributed to consider new approaches including chemical evaluation of latent fingermarks. Significant improvement to the detection of small organic molecules has been reached with matrix-free methods associated to laser desorption/ionization mass spectrometry. The present study investigated the application of mesocellular siliceous foam (MCF) as an ionizing agent for laser desorption/ionization (LDI-MS) analysis of fingermarks as a proof of concept research. Fingermarks from three different donors were deposited directly onto a MALDI target plate and α-CHCA matrix solution, MCF ethanolic suspension or MCF/magnetic powder mixture were used for treatment. Microscopy characterization of MCF support showed particles with irregular morphology and variable sizes, and a unordered porous surface with pores diameter ranging from about 10 to 20 nm. Results showed less intense peaks in the spectra produced by the MCF support (control). Analysis of fingermarks showed ions related to endogenous and exogenous molecular components, including possible lipids from human sebum and quaternary ammonium cations commonly present in cosmetics. Promising and reproducible results were obtained for the fingermarks dusted with the MCF/magnetic powder mixture. Considering the forensic applications of nanomaterials for the analysis of small molecules in biological samples by matrix-free LDI techniques, the advantages of silica based materials should be further investigated.


Assuntos
Dermatoglifia , Dióxido de Silício/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Adulto , Ciências Forenses/métodos , Humanos , Magnetismo , Masculino , Nanoestruturas , Pós
2.
Int J Sports Med ; 30(11): 827-33, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19629927

RESUMO

The purpose of this study was to compare the two main types of marker sets for human body representation based on rigid clusters of markers and skin surface markers for measuring kinematics during walking and running. Velocity, body segment, and joint angle were considered in the comparison of both protocols. Six male athletes were studied during treadmill gait at 1.4 and 5.5 m/s and recorded with 8 high speed video cameras. The subjects used simultaneously both protocols in the same walking and running cycles, in order to compare the variability in the determination of the joint centers' positions and the joint angles calculated from each protocol. The three-way ANOVA results showed that the variability of the inter-markers distance in the skin surface protocol was higher than that in the rigid clusters of markers, as reported in the literature. However, no statistical differences between the protocols were found in the variability of the determination of the joint centers' positions. Therefore no advantage was verified to rigid cluster protocols even for the upper body segments. Another conclusion is that increases in velocity produced increases in variability of the joint centers' distances and increases in the maximum differences between the joint angles.


Assuntos
Corrida/fisiologia , Pele , Caminhada/fisiologia , Adolescente , Análise de Variância , Fenômenos Biomecânicos , Teste de Esforço , Humanos , Articulações/fisiologia , Masculino , Modelos Biológicos , Adulto Jovem
3.
Funct Neurol ; 33(3): 137-142, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30457966

RESUMO

The required coefficient of friction (RCOF) is frequently reported in the literature as an indicator of slip propensity, a consequence of the collisional aspect of legged locomotion. Little is known about the RCOF in pathological gait. Therefore, this study aimed to quantify the RCOF in subjects with Parkinson's disease (PD) and freezing of gait (FOG) during the OFF-pharma phase, and to investigate the interplay between RCOF parameters and ankle kinematic and kinetic gait variables. Fourteen subjects with PD and 14 healthy age-matched subjects were instructed to walk barefoot at self-selected speed over a force platform. The RCOF curve was obtained as the ratio between the tangential and vertical ground reaction forces. Then, the following discrete variables were identified: P1COF (the peak at the loading response phase), V1COF (the valley at midstance phase) and P2COF (the peak at push-off phase). Stepwise multiple regressions were applied to observe the influence of the gait speed and ankle kinematic and kinetic gait variables on RCOF variables. In subjects with PD and FOG the gait speed is a predictor of the RCOF in the loading response phase; plantarflexion and the plantarflexion moment are strong predictors of the RCOF in midstance; finally, push-off power is a predictor of RCOF increasing in the push-off phase. These results characterized the biomechanical strategies adopted by subjects with PD and FOG during gait in order to avoid falls.


Assuntos
Fricção , Marcha , Doença de Parkinson/fisiopatologia , Idoso , Fenômenos Biomecânicos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
4.
J Dairy Sci ; 89(2): 483-94, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16428617

RESUMO

Crude mixtures of aspartic proteases from flowers of the plant Cynara cardunculus have been studied frequently, as have activities of such enzymes (in pure form) on caseins from bovine, ovine, and caprine sources. This research study addressed pure bovine whey protein as substrates; that is, alpha-lactalbumin (alphaLA) and beta-lactoglobulin (alpha-LG), submitted to hydrolysis by 1 of 2 aspartic proteases (cardosins A and B), previously extracted and purified from C. cardunculus. Samples collected, following incubation at 55 degrees C and pH 5.2, were assayed by fast protein liquid chromatography, reversed phase-high performance liquid chromatography, and tricine-sodium dodecyl sulfate polyacrylamide gel electrophoresis; the major peptides released were then collected and sequenced by Edman degradation. Cardosin B and, to a lesser degree, cardosin A showed proteolytic activity toward alpha-LA, but the hydrolyzates produced were characterized by distinct peptide profiles. Cardosin B possesses a broad specificity, and produces several hydrophobic peptides (at least 5, with molecular mass in the range 2 to 8 kDa) in the early stages, which eventually become more hydrophilic (with molecular mass below 2 kDa) at later stages of hydrolysis. Cardosin A was found to cleave alpha-LA at the peptide bonds Phe28-Arg29, Gly54-Tyr55, Ala59-Ile60, Leu71-Phe72, and Leu105-Thr106, whereas cardosin B cleaved Ala19-Glu20, Phe28-Arg29, Glu30-Leu31, Tyr37-Gly38, Trp45-Val46, Phe50-His51, Ala59-Ile60, Ser66-Thr67, Leu71-Phe72, Phe72-Gln73, Gln73-Ile74, Ile78-Trp79, Leu115-Asp116, and Leu124-Ala125. Conversely, cardosins A and B are apparently not active on beta-LG.


Assuntos
Ácido Aspártico Endopeptidases/metabolismo , Lactalbumina/metabolismo , Lactoglobulinas/metabolismo , Fragmentos de Peptídeos/análise , Proteínas de Plantas/metabolismo , Sequência de Aminoácidos , Animais , Bovinos , Cromatografia Líquida de Alta Pressão , Eletroforese em Gel de Poliacrilamida , Concentração de Íons de Hidrogênio , Hidrólise , Peso Molecular , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/metabolismo , Análise de Sequência de Proteína , Especificidade por Substrato
5.
Braz J Med Biol Res ; 45(6): 537-45, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22473324

RESUMO

The aim of this study was to analyze the alterations of arm and leg movements of patients during stroke gait. Joint angles of upper and lower limbs and spatiotemporal variables were evaluated in two groups: hemiparetic group (HG, 14 hemiparetic men, 53 ± 10 years) and control group (CG, 7 able-bodied men, 50 ± 4 years). The statistical analysis was based on the following comparisons (P ≤ 0.05): 1) right versus left sides of CG; 2) affected (AF) versus unaffected (UF) sides of HG; 3) CG versus both the affected and unaffected sides of HG, and 4) an intracycle comparison of the kinematic continuous angular variables between HG and CG. This study showed that the affected upper limb motion in stroke gait was characterized by a decreased range of motion of the glenohumeral (HG: 6.3 ± 4.5, CG: 20.1 ± 8.2) and elbow joints (AF: 8.4 ± 4.4, UF: 15.6 ± 7.6) on the sagittal plane and elbow joint flexion throughout the cycle (AF: 68.2 ± 0.4, CG: 46.8 ± 2.7). The glenohumeral joint presented a higher abduction angle (AF: 14.2 ± 1.6, CG: 11.5 ± 4.0) and a lower external rotation throughout the cycle (AF: 4.6 ± 1.2, CG: 22.0 ± 3.0). The lower limbs showed typical alterations of the stroke gait patterns. Thus, the changes in upper and lower limb motion of stroke gait were identified. The description of upper limb motion in stroke gait is new and complements gait analysis.


Assuntos
Braço/fisiologia , Marcha/fisiologia , Perna (Membro)/fisiologia , Paresia/fisiopatologia , Acidente Vascular Cerebral/fisiopatologia , Adulto , Pontos de Referência Anatômicos , Fenômenos Biomecânicos , Articulação do Cotovelo/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Movimento/fisiologia , Amplitude de Movimento Articular , Articulação do Ombro/fisiopatologia , Estatísticas não Paramétricas
6.
Comput Methods Biomech Biomed Engin ; 14(9): 783-95, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21360362

RESUMO

Segmentation of the 3D human body is a very challenging problem in applications exploiting volume capture data. Direct clustering in the Euclidean space is usually complex or even unsolvable. This paper presents an original method based on the Isomap (isometric feature mapping) transform of the volume data-set. The 3D articulated posture is mapped by Isomap in the pose of Da Vinci's Vitruvian man. The limbs are unrolled from each other and separated from the trunk and pelvis, and the topology of the human body shape is recovered. In such a configuration, Hoshen-Kopelman clustering applied to concentric spherical shells is used to automatically group points into the labelled principal curves. Shepard interpolation is utilised to back-map points of the principal curves into the original volume space. The experimental results performed on many different postures have proved the validity of the proposed method. Reliability of less than 2 cm and 3° in the location of the joint centres and direction axes of rotations has been obtained, respectively, which qualifies this procedure as a potential tool for markerless motion analysis.


Assuntos
Corpo Humano , Modelos Biológicos , Humanos
7.
Transplant Proc ; 43(7): 2481-6, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21911109

RESUMO

BACKGROUND: Kidney donation is associated with few adverse outcomes in living donors. The aim of this study was to evaluate the outcomes of living kidney donors and the utility of creatinine-based equations to predict chronic kidney disease. METHODS: The study population was selected among 154 living kidney donors from 2001 to 2009. Seventy-eight patients underwent medical consultation to review demographic data and perform laboratory evaluations. Estimated glomerular filtration rate (GFR) values were obtained by three equations: Modification of Diet in Renal Disease (MDRD), Cockcroft-Gault (C-G) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI). Receiver operating characteristic (ROC) analysis was performed to determine the area under the curve of each equation to predict evolution to chronic kidney disease. RESULTS: The overall median age was 39 years including 64% of women subjects. The mean follow-up after kidney donation was 65 ± 34 months. During follow-up, 20.5% of patients developed hypertension. Serum creatinine values above 1.5 mg/dL were detected in 14.1% of cases. Dyslipidemia was present in 33.3% of donors at the last follow-up. According to measured creatinine clearance and the C-G equation, only four and six donors had renal failure (defined as GFR < 60 mL/min), a number that increased to 23 (29.4%) when considering the MDRD or CKD-EPI equations (P < .05). ROC curves performed to explore the GFR measurements to predict renal failure occurrence after donation showed the CKD-EPI to be the only one with a significant area under the curve (0.7442, P = .003). CONCLUSION: Living kidney donors should receive careful long-term follow-up. Assessment of renal function before donation using CKD-EPI creatinine-based equations must be performed preferentially. A careful approach should be adopted for the detection and treatment of other complications such as hypertension and dyslipidemia.


Assuntos
Creatinina/urina , Falência Renal Crônica/urina , Doadores Vivos , Adulto , Feminino , Taxa de Filtração Glomerular , Humanos , Falência Renal Crônica/fisiopatologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Curva ROC
8.
Comput Methods Biomech Biomed Engin ; 13(3): 387-96, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19802754

RESUMO

In this paper, we propose a method to estimate the parameters of a double hinge model of the trapeziometacarpal joint (TMC) by MRI-based motion analysis. The model includes two non-orthogonal and non-intersecting rotation axes accounting for flexion-extension (F-E) and adduction-abduction (A-A). We evaluated the quality of the estimated model parameters in the prediction of the relative motion of the first metacarpal bone with respect to the trapezium. As a result, we obtained that: (a) the estimated location and orientation of the F-E and A-A axes were in agreement with previous in vitro studies, (b) the motion of the first metacarpal predicted by the 2 degrees of freedom (2DoF) model exhibits a maximum surface distance error in the range of about 2 mm and (c) four thumb postures at the boundary of the TMC range of motion are sufficient to provide a good estimation of the 2DoF TMC kinematic model and good reproducibility (~1.7 mm) of the real thumb motion at TMC level.


Assuntos
Fenômenos Biomecânicos , Articulações Carpometacarpais/anatomia & histologia , Imageamento por Ressonância Magnética/métodos , Trapézio/anatomia & histologia , Adulto , Humanos , Masculino
10.
Vet Pathol ; 45(4): 542-5, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18587103

RESUMO

Two cases of patent ductus arteriosus are described in 2 Murrah buffalos, a 7.5-month-old heifer calf and a 5-month-old bull calf. The main clinical signs consisted of exercise intolerance, dyspnea, and tachycardia. At necropsy, lesions were consistent with congestive heart failure as indicated by dependent subcutaneous edema, body cavity effusions, and nutmeg liver. The lungs were extensively atelectatic. The heart was enlarged and had a globous shape. The ductus arteriosus, measuring 0.8 cm in length and 0.4 cm in caliber, was patent. The proximal pulmonary artery had an approximately 50-mm-long aneurysm. Eccentric cardiac hypertrophy was evident primarily in the right but to a lesser degree also in the left ventricle. Additionally, there was diffuse subendocardial fibrosis in the left and right ventricle. To the best of the authors' knowledge, patent ductus arteriosus was not previously described in buffalos. Since both calves were sired by the same bull, it is possible that this cardiac anomaly has a hereditary basis.


Assuntos
Búfalos , Permeabilidade do Canal Arterial/veterinária , Animais , Permeabilidade do Canal Arterial/patologia , Evolução Fatal , Feminino , Histocitoquímica/veterinária , Masculino
11.
Ann Biomed Eng ; 36(7): 1268-80, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18425581

RESUMO

This article analyzes a realistic kinematic model of the trapezio-metacarpal (TM) joint in the human thumb that involves two non-orthogonal and non-intersecting rotation axes. The estimation of the model parameters, i.e. the position and orientation of the two axes with respect to an anatomical coordinate system, was carried out by processing the motion of nine retroreflective markers, externally attached to the hand surface, surveyed by a video motion capture system. In order to compute the model parameters, prototypical circumduction movements were processed within an evolutionary optimization approach. Quality and reproducibility in assessing the parameters were demonstrated across multiple testing sessions on 10 healthy subjects (both left and right thumbs), involving the complete removal of all markers and then retesting. Maximum errors of less than 5 mm in the axis position and less than 6 degrees in the orientation were found, respectively. The inter-subject mean distance between the two axes was 4.16 and 4.71 mm for right and left TM joints, respectively. The inter-subject mean relative orientation between the two axes was about 106 and 113 degrees for right and left TM joints, respectively. Generalization properties of the model were evaluated quantitatively on opposition movements in terms of distance between measured and predicted marker positions (maximum error less than 5 mm). The performance of the proposed model compared favorably with the one (maximum error in the range of 7-8 mm) obtained by applying a universal joint model (orthogonal and intersecting axes). The ability of in vivo estimating the parameters of the proposed kinematic model represents a significant improvement for the biomechanical analysis of the hand motion.


Assuntos
Fenômenos Biomecânicos/métodos , Articulações dos Dedos/fisiologia , Articulação Metacarpofalângica/fisiologia , Modelos Biológicos , Polegar/fisiologia , Trapézio/fisiologia , Simulação por Computador , Eletrônica/instrumentação , Humanos , Óptica e Fotônica , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
12.
Ann Biomed Eng ; 35(11): 1989-2002, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17701355

RESUMO

This paper describes methods and experimental studies concerned with quantitative reconstruction of finger movements in real-time, by means of multi-camera system and 24 surface markers. The approach utilizes a kinematic model of the articulated hand which consists in a hierarchical chain of rigid body segments characterized by 22 functional degrees of freedom and the global roto-translation. This work is focused on the experimental evaluation of a kinematical hand model for biomechanical analysis purposes. From a static posture, a completely automatic calibration procedure, based on anthropometric measures and geometric constraints, computes axes, and centers of rotations which are then utilized as the base of an interactive real-time animation of the hand model. The motion tracking, based on automatic marker labeling and predictive filter, is empowered by introducing constraints from functional finger postures. The validation is performed on four normal subjects through different right-handed motor tasks involving voluntary flexion-extension of the thumb, voluntary abduction-adduction of the thumb, grasping, and finger pointing. Performances are tested in terms of repeatability of angular profiles, model-based ability to predict marker trajectories and tracking success during real-time motion estimation. Results show intra-subject repeatability of the model calibration both to different postures and to re-marking in the range of 0.5 and 2 mm, respectively. Kinematic estimation proves satisfactory in terms of prediction capability (index finger: maximum RMSE 2.02 mm; thumb: maximum RMSE 3.25 mm) and motion reproducibility (R (2) coefficients--index finger: 0.96, thumb: 0.94). During fast grasping sequence (60 Hz), the percentage of residual marker occlusions is less than 1% and processing and visualization frequency of 50 Hz confirms the real-time capability of the motion estimation system.


Assuntos
Dedos , Modelos Biológicos , Movimento (Física) , Polegar/fisiologia , Articulação do Punho/fisiologia , Fenômenos Biomecânicos/métodos , Humanos , Reprodutibilidade dos Testes , Fatores de Tempo
13.
Braz. j. med. biol. res ; 45(6): 537-545, June 2012. ilus, tab
Artigo em Inglês | LILACS | ID: lil-622780

RESUMO

The aim of this study was to analyze the alterations of arm and leg movements of patients during stroke gait. Joint angles of upper and lower limbs and spatiotemporal variables were evaluated in two groups: hemiparetic group (HG, 14 hemiparetic men, 53 ± 10 years) and control group (CG, 7 able-bodied men, 50 ± 4 years). The statistical analysis was based on the following comparisons (P ≤ 0.05): 1) right versus left sides of CG; 2) affected (AF) versus unaffected (UF) sides of HG; 3) CG versus both the affected and unaffected sides of HG, and 4) an intracycle comparison of the kinematic continuous angular variables between HG and CG. This study showed that the affected upper limb motion in stroke gait was characterized by a decreased range of motion of the glenohumeral (HG: 6.3 ± 4.5, CG: 20.1 ± 8.2) and elbow joints (AF: 8.4 ± 4.4, UF: 15.6 ± 7.6) on the sagittal plane and elbow joint flexion throughout the cycle (AF: 68.2 ± 0.4, CG: 46.8 ± 2.7). The glenohumeral joint presented a higher abduction angle (AF: 14.2 ± 1.6, CG: 11.5 ± 4.0) and a lower external rotation throughout the cycle (AF: 4.6 ± 1.2, CG: 22.0 ± 3.0). The lower limbs showed typical alterations of the stroke gait patterns. Thus, the changes in upper and lower limb motion of stroke gait were identified. The description of upper limb motion in stroke gait is new and complements gait analysis.


Assuntos
Adulto , Humanos , Masculino , Pessoa de Meia-Idade , Braço/fisiologia , Marcha/fisiologia , Perna (Membro)/fisiologia , Paresia/fisiopatologia , Acidente Vascular Cerebral/fisiopatologia , Pontos de Referência Anatômicos , Fenômenos Biomecânicos , Articulação do Cotovelo/fisiopatologia , Movimento/fisiologia , Amplitude de Movimento Articular , Estatísticas não Paramétricas , Articulação do Ombro/fisiopatologia
14.
Chromosome Res ; 13(4): 339-47, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15973499

RESUMO

The Neotropical Phyllostomidae family is the third largest in the order Chiroptera, with 56 genera and 140 species. Most researchers accept this family as monophyletic but its species are anatomically diverse and complex, leading to disagreement on its systematics and evolutionary relationships. Most of the genera of Phyllostomidae have highly conserved karyotypes but with intense intergeneric variability, which makes any comparative analysis using classical banding difficult. The use of chromosome painting is a modern way of genomic comparison on the cytological level, and will clarify the intense intergenus chromosomal variability in Phyllostomidae. Whole chromosome probes of species were produced as a tool for evolutionary studies in this family from two species from different subfamilies, Phyllostomus hastatus and Carollia brevicauda, which have large morphological and chromosomal differences, and these probes were used in reciprocal chromosome painting. The hybridization of the Phyllostomus probes on the Carollia genome revealed 24 conserved segments, while the Carollia probes on the Phyllostomus genome detected 26 segments. Many chromosome rearrangements have occurred during the divergence of these two genera. The sequence of events suggested a large number of rearrangements during the differentiation of the genera followed by high chromosomal stability within each genus.


Assuntos
Quirópteros/genética , Coloração Cromossômica , Cromossomos de Mamíferos/genética , Animais , Fibroblastos , Citometria de Fluxo , Genoma , Cariotipagem , Metáfase , América do Sul
15.
Genetica ; 85(3): 249-57, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1521801

RESUMO

The karyotype of Cebuella pygmaea (2n = 44) obtained by G-, C-banding, and NOR-staining is described. This species presents a heteromorphic C band in the intersticial region of the short arm of chromosome 2. The data obtained were compared with those previously described for the karyotypes of Callithrix jacchus and Callithrix emiliae. The three species differ in the amount and distribution of non-centromeric constitutive heterochromatin. The importance of the variation in constitutive heterochromatin for the phylogeny of the group is discussed. Comparison of the karyotypes in terms of G-banding patterns showed that C. pygmaea and C. emiliae differ from C. jacchus by a Robertsonian translocation and a paracentric inversion, whereas C. pygmaea and C. emiliae differ from each other by a reciprocal translocation between an acrocentric autosome and the short arm of the submetacentric chromosomes that distinguishes their karyotypes from that of C. jacchus. The possible evolutionary paths followed by the karyotypes of the three species are discussed.


Assuntos
Callitrichinae/genética , Cariotipagem/veterinária , Animais , Callithrix/genética , Callitrichinae/classificação , Bandeamento Cromossômico , Feminino , Masculino
16.
Cytobios ; 101(398): 161-72, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10755215

RESUMO

The neotropical primate genus Callithrix comprises two groups of species, jacchus and argentata, which inhabit distinct geographical regions and manifest different fur coloration and constitutive heterochromatin (CH) markers in their karyotypes. In this investigation the CH of a representative of the jacchus group, Callithrix geoffroyi, was analysed using fluorochromes and restriction enzymes in situ. To clarify the source of the constitutive heterochromatin of both groups, the data obtained in the jacchus group were compared with those published in the argentata group obtained by the same techniques. The C-bands of C. geoffroyi (four specimens, 2n = 46) were centromeric in all chromosomes, and distally located in pairs 6 and 22. The Alu I, Hae III, Hin fI, Rsa I, Dde I, Mbo I, and Msp I restriction endonucleases and CMA3 and DAPI fluorochromes produced different bands, which allowed the characterization of four distinct types of constitutive heterochromatin in the C. geoffroyi genome. Several of these types of heterochromatin were present in the ancestor of the two groups of species, jacchus and argentata, while others originated after their cladogenesis.


Assuntos
Callithrix/genética , Heterocromatina/genética , Animais , Bandeamento Cromossômico , Enzimas de Restrição do DNA , Feminino , Corantes Fluorescentes , Cariotipagem , Masculino , Mapeamento por Restrição
17.
Am J Primatol ; 43(3): 265-76, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9359969

RESUMO

The karyotypes of two taxa of genus Leontopithecus (rosalia and chrysomelas) are studied. Their G-, C- and NOR-banding patterns are compared with those of representatives of the genus Saguinus to determine chromosomal similarities and differences between the two genera and thus contribute to explaining phylogenetic relations between the tamarins. Leontopithecus, like the Saguinus, presents 2n = 46, 14 autosomes plus the Y acrocentric and 30 autosomes plus the X biarmed. No chromosomal rearrangement distinguishes the karyotypes of the representatives of genus Leontopithecus or genus Saguinus. The two genera are distinguished from each other by a paracentric inversion and pericentric inversions on at least four pairs of acrocentric autosomes, displacing the NORs of the small short arms in Leontopithecus to the proximal region of the long arms in Saguinus or vice versa. The tamarins are also distinguished by the distribution of noncentromeric constitutive heterochromatin. The data obtained indicate that the two tamarin genera are closely related chromosomally, suggesting that they probably originated from the same ancestral branch.


Assuntos
Callitrichinae/genética , Saguinus/genética , Animais , Cromossomos/ultraestrutura , Classificação , Feminino , Heterocromatina , Cariotipagem , Masculino
18.
Cytogenet Cell Genet ; 72(4): 325-30, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8641141

RESUMO

The karyotypes of the species belonging to the group Callithrix argentata (Callitrichidae, Platyrrhini) are characterized by large amounts of distal constitutive heterocharomatin (CH). The CH of the species C. argentata, C. humeralifera and C. emiliae was analyzed by banding with the restriction enzymes HinfI, MboI, aluI, RsaI, DdeI, HaeIII and MspI, as well as the fluorochromes CMA3 and DAPI. The results obtained permitted us to classify the CH of these species into three distinct types: 1) distal CH with a homogeneous response to enzymatic action, which was unchanged (HinfI, MboI, AluI, HaeIII), partially digested (DdeI) or fully digested (RsaI), being CMA3+, DAPI-; 2) centromeric CH, generally presenting a reduced band size. The varying extent of reduction, ranging from none to total, and also the variation of fluorochrome staining indicates that there is heterogeneity in this type of CH; 3) CH of the distal portion of the X chromosome of C. argentata and of the Y chromosome was CMA3- and unchanged by the enzymes, except for RsaI, which caused a reduction in size. MspI was the only enzyme unable to induce bands. Sequential C-banding permitted us to perceive banding variations that could not be observed simply by RE banding.


Assuntos
Callithrix/genética , Heterocromatina/genética , Animais , Callithrix/classificação , Bandeamento Cromossômico , Enzimas de Restrição do DNA , Feminino , Corantes Fluorescentes , Cariotipagem , Masculino , Especificidade da Espécie , Cromossomo X/genética , Cromossomo Y/genética
19.
Chromosoma ; 99(6): 440-7, 1990 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-2272240

RESUMO

We studied the karyotype of specimens of Callithrix emiliae (Callithricidae, Primates) from Rondonia, Brazil. Comparison with the karyotype of Callithrix jacchus showed that, even though these two species show many karyotypic similarities, they differ by a Robertsonian translocation, a paracentric inversion and large-scale addition of heterochromatin. The C. emiliae species appears to be in an active phase of chromosome evolution by the addition of constitutive heterochromatin.


Assuntos
Evolução Biológica , Callithrix/genética , Cromossomos/ultraestrutura , Animais , Feminino , Cariotipagem/veterinária , Masculino , Translocação Genética/genética
20.
Enzyme Microb Technol ; 28(7-8): 642-652, 2001 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-11339948

RESUMO

Blends of cardosins A and B, enzymes present in aqueous extracts of the flowers of the thistle (Cynara cardunculus L.), have for long been used as rennets by the cheesemaking industry in the Iberian Peninsula. These dimeric proteases are present in the stigmae and stylets of said flowers, and are thought to play a role in sexual reproduction of the plant. In the present research effort, production of cardosin derivatives (starting from a crude extract), encompassing full stabilization of their dimeric structure, has been attempted via covalent, multi-subunit immobilization onto highly activated agarose-glutaraldehyde supports. Boiling such enzyme derivatives in the presence of sodium dodecyl sulfate and beta-mercaptoethanol did not lead to leaching of enzyme, thus proving the effectiveness of the attachment procedure. Furthermore, derivatives prepared under optimal conditions presented ca. half the specific activity of the enzyme in soluble form, and were successfully employed at lab-scale trials to perform (selective) hydrolysis of alpha-lactalbumin, one of the major proteins in bovine whey.

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