The required coefficient of friction in Parkinson's disease: people with freezing of gait.

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.

Application of mesocellular siliceous foams (MCF) for surface-assisted laser desorption ionization mass spectrometry (SALDI-MS) Analysis of fingermarks.

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.

Three-dimensional kinematic analysis of upper and lower limb motion during gait of post-stroke patients

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.

Three-dimensional kinematic analysis of upper and lower limb motion during gait of post-stroke patients.

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.

Creatinine-based equations predicting chronic kidney disease after kidney donation.

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.

Isomap transform for segmenting human body shapes.

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.

Method for the estimation of a double hinge kinematic model for the trapeziometacarpal joint using MR imaging.

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.

Comparison of protocols for walking and running kinematics based on skin surface markers and rigid clusters of markers.

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.

Dois métodos diferentes para análise cinemática dos movimentos de cabeça durante a coordenação viso-cefálica de lactentes / Two different methods for kinematic analysis of head movements relating to eye-head coordination in infants

CONTEXTUALIZAÇÃO: A análise cinemática é um método de avaliação quantitativa empregada em diferentes áreas de estudo. Na área do desenvolvimento motor, essa análise pode proporcionar uma melhor compreensão da aquisição e do desenvolvimento das habilidades motoras. OBJETIVOS: Desenvolver e comparar dois arranjos experimentais para análise cinemática dos movimentos de cabeça durante a coordenação viso-cefálica (CVC) em lactentes. MATERIAIS E MÉTODOS: Foram testados dois arranjos experimentais (A e B) que diferiam quanto ao número e posicionamento das câmeras, bem como quanto ao volume do sistema de calibração. RESULTADOS: A acurácia dos dois arranjos experimentais foi de 2,47mm, indicando que ambos podem fornecer uma reconstrução verossímil do movimento. As três câmeras usadas no arranjo B favoreceram a visualização de toda a amplitude do movimento por pelo menos uma das câmeras. Isso levou à melhora da análise qualitativa e à redução do tempo de processamento dos dados quantitativos, reduzindo-o em 33 por cento quando comparado ao arranjo A. Além disso, o arranjo B apresentou melhor relação custo-benefício. CONCLUSÕES: Ambos os arranjos são adequados para a análise cinemática dos movimentos de cabeça durante a CVC de lactentes, entretanto, o arranjo B é mais vantajoso. A metodologia do arranjo B pode ser empregada em estudos que investigam o movimento de cabeça de lactentes, sejam eles típicos ou atípicos. Os resultados de tais estudos poderão ser empregados para complementar a avaliação de lactentes de risco e, conseqüentemente, auxiliar na intervenção precoce destes.

BACKGROUND: Kinematic analysis is a method for quantitative assessment applied in different fields of study. In the field of motor development, this analysis may promote better understanding of the acquisition and development of motor skills. OBJECTIVE: To develop and compare two experimental set-ups for kinematic analysis of head movements relating to eye-head coordination (EHC) in infants. METHODS: Two experimental set-ups (A and B) were tested. They differed from each other regarding the numbers and locations of the cameras, and regarding the volume of the calibration system. RESULTS: The accuracy of the two experimental set-ups was 2.47mm, thus indicating that both can provide realistic reconstructions of the movement. The three cameras used in set-up B made it possible to view the full range of motion with at least one of the cameras. This led to improvement of the qualitative analysis and reduction of the time taken to process quantitative data, which was 33 percent shorter than seen with set-up A. In addition, set-up B presented a better cost-benefit relationship. CONCLUSIONS: Although both set-ups were adequate for kinematic analysis of head movements relating to EHC in infants, set-up B is more advantageous. The methodology for set-up B can be used in studies investigating head movements in either typical or atypical infants. The results from such studies could be used to complement assessments on at-risk infants and consequently could assist in implementing early interventions.

Patent ductus arteriosus in Murrah buffalos.

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.

In vivo validation of a realistic kinematic model for the trapezio-metacarpal joint using an optoelectronic system.

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.

Finger kinematic modeling and real-time hand motion estimation.

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.

Análise cinemática tridimensional do movimento de eqüinos em esteira rolante / Three-dimensional cinematic analysis of the horse movement in treadmill

Adaptou-se uma metodologia utilizada no estudo do movimento humano para analisar o movimento de eqüinos em esteira rolante de alto desempenho, construindo-se um sistema de calibração utilizando-se um teodolito eletrônico de alta precisão e calibradores que demarcavam o espaço ocupado pelo animal. Dessa forma, foram obtidas as coordenadas espaciais dos marcadores presentes nos calibradores, compondo o arquivo de calibração. Duas câmeras de vídeo (60Hz) foram posicionadas em vista lateral esquerda, distantes 5m da manta de rolagem da esteira a 1,8m de altura. As imagens foram enquadradas utilizando-se um monitor de vídeo. Para a validação do método, um membro da equipe movimentou, no espaço calibrado, uma haste rígida com marcadores fixados nas suas extremidades, distantes um do outro 43,8cm. Para a análise das imagens, utilizou-se o programa Dvideow, desenvolvido pelo Laboratório de Instrumentação para Biomecânica - UNICAMP. Após a reconstrução tridimensional das imagens utilizou-se um programa matemático para o cálculo do valor médio da distância entre os marcadores. Obteve-se, após a mensuração em 100 quadros, o valor médio de 43,7cm com coeficiente de variação de 0,8 por cento. Estes resultados mostram que a metodologia desenvolvida é precisa e adequada para o estudo da locomoção de eqüinos

A methodology used for the study of human movement was adapted to analyze the movement of equines in a high performance treadmill. An electronic high precision theodolite was used to construct a calibration system to demarcate the volume occupied by the animal. It was taken the three dimensions coordinates of each marker present in the calibrator, composing the calibration archive. Two video cameras (60 Hz) were located approximately 5m from the left lateral side of the treadmill at 1.8m height. The images had been fit using a video monitor. For the validation of the method, a member of the team moved into the calibrated space, a 43.8cm long rigid stick with markers settled in its extremities. For the analysis of the images, the Dvideow program developed by the Laboratório de Instrumentação para Biomecânica - UNICAMP was used. After the three-dimensional reconstruction of the images, the calculation of the distance between the markers of the stick was done in 100 frames. The mean was 43.7 cm with a variation coefficient of 0.8 percent. These results confirm that this methodology is precise and adequate for the study of the locomotion in horses

Molecular characterization of peptides released from beta-lactoglobulin and alpha-lactalbumin via cardosins A and B.

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.

Reciprocal chromosome painting between two South American bats: Carollia brevicauda and Phyllostomus hastatus (Phyllostomidae, Chiroptera).

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.

Utilização do sistema Dvideow na analise cinematica do alcance manual de lactentes / Utilization of the Dvideow system in kinematic analysis of infants reaching movements

A analise cinematica tem sido utilizada como metodo de avaliacao para aumentar os conhecimentos sobre aquisicao e o desenvolvimento do alcance manual em lactentes. Metodos: quatro lactentes com idade de 4 a 6 meses (5+- 0,816) serviram como modelos para a adaptacao dessa metodologia. A condicao experimental consistiuna apresentacao de um brinquedo, na altura dos ombros dos lactentes. As avaliacoes foram filmadas e analisadas pelo sistema Dvideow. Foram testados o numero e a localizacao das cameras e dos iluminadores, alem do posicionamento e tamanho dos marcadores. Resultados: foi necessario utilizar, no minimo, 3 cameras digitais. A fim de possibilitar uma analise simultanea de ambos os membros superiores, uma das cameras foi posicionada atras e acima dos lactentes, enquanto duas outras foram colocadas nas laterais direita e esquerda. Para garantir a reflexao dos marcadores, foi necessario iluminar o lactente indiretamente, pois a luz direta interferia em seu comportamento. Marcadores esfericos de 0,5 cm proporcionaram maior precisao durante a analise. Os resultados obtidos foram apresentados de acordo com a trajetoria linear e angular de 10 alcances avaliados. Conclusao: Essa metodologia permite a analise cinematica do movimento de lactentes, a qual pode ser extremamente util para a compreensao do alcance de lactentes saudaveis

A influencia da estimulacao eletrica funcional associada ao treinamento em esteira com suporte parcial de peso na marcha de Hemipareticos / Influence on hemiparetic patients gait abilities from electrial functional stimulation during treadmill training with partial weight support

Avaliar os efeitos do treino em esteira eletrica com suporte parcial de peso associado a estimulacao eletrica funcional na marcha de sujeitos hemiplegicos por meio da analise de variaveis espaco-temporais. Metodo: para tal proposito foi utilizado o sistema A1-B-A2,no qual A1 e A2 correspondem ao treinamento em esteira eletrica com suporte parcial de peso e B, ao mesmo treinamento associado a estimulacao eletrica funcional. participaram deste estudo dois pacientes hemiparetcos cronicos que foram submetidos a treinamento durante 45 minutos, tres vezes por semana durante 9 semanas...

Chromosomal studies in Callicebus donacophilus pallescens, with classic and molecular cytogenetic approaches: multicolour FISH using human and Saguinus oedipus painting probes.

This paper presents the karyotype of Callicebus donacophilus pallescens for the first time. The analysis included G-, C-, NOR-banding techniques and FISH with chromosome painting probes from Saguinus oedipus and Homo sapiens. The results were compared with the karyotypes of Callicebus moloch donacophilus and C. moloch previously published. These three karyotypes display the same diploid number (2n = 50) but diverge about the number of biarmed and acrocentric chromosomes. The acrocentrics 14 and 15 from C. m. donacophilus and C. moloch have undergone an in-tandem fusion originating a large acrocentric (pair 10) in C. d. pallescens. The major submetacentric pair (pair 1) from C. d. donacophilus and C. moloch have undergone fission originating two acrocentric pairs in C. d. pallescens (pairs 15 and 22). Herein was evidence that, in spite of the high interspecific variation among Callicebus, most of the chromosomes remained conserved.

Cytogenetic study of Callicebus hoffmannsii (Cebidae, Primates) and comparison with C. m. moloch.

Callicebus is a neotropical primate genus divided into four or five groups of species. Species of the moloch group are distributed in the tropical forests of the Amazon basin. The karyotype of Callicebus hoffmannsii (moloch group) was studied by means of G- and C-banding, Ag-NOR staining and in situ hybridization of telomeric probes. C. hoffmannsii had 2n = 50 chromosomes, with ten biarmed and fourteen acrocentric autosomal pairs. The X chromosome was submetacentric and the Y chromosome was a minor acrocentric. Constitutive heterochromatin was detected in the centromeric regions of all chromosomes; in pairs 7 and 10, it was found in the distal regions of the short arms, and distally in the long arm of the X chromosome. Size heteromorphism in C-bands was detected in pairs 7 and 10. Ag-NOR staining revealed a maximum of three nucleolar organizers. Telomeric probes hybridized only at the terminal regions of all chromosomes. Additionally, a comparison was carried out between C. hoffmannsii and C. m. moloch (2n = 48), as previously reported. Both species shared gross chromosomal similarities diverging by a single rearrangement of centric fusion/fission. A high similarity between C. hoffmannsii and C. donacophilus indicated a close association between the moloch and donacophilus groups.

Cytogenetic studies on Choeroniscus minor (Chiroptera, Phyllostomidae) from the Amazon region.

The Choeroniscus genus (Glossophaginae, Phyllostomidae) has five monotypic species: C. minor, C. godmani, C. intermedius, C. inca and C. periosus. This paper analyses the karyotype of a female C. minor, collected close to the Guama river (Belém, Para, Brazil). G-, C-banding and NOR-staining were performed. This species has 2n = 20 chromosomes, where there are two bi-armed pairs (numbers 1 and 9) and seven subtelocentric pairs (2, 3, 4, 5, 6, 7 and 8). The probable X chromosome is a submetacentric. The constitutive heterochromatin can be found in the short arm of five subtelocentric pairs (4, 5, 6, 7 and 8) and is centromeric in the bi-armed pairs numbers 1 and 9, and the X chromosome. The heterochromatic bands are heteromorphic in three pairs (1, 2 and 3). Active NOR were observed in the short arms of eight subtelocentric chromosomes, suggesting that at least four pairs are nucleolar organizers. This paper describes for the first time the karyotype of C. minor from the Amazon region.