RESUMO
While fasciotomy is the only urgent treatment option for compartment syndrome, the resulting open wound leaves room for complications. Closure of the wound can be done by different techniques, including split-thickness skin grafts, negative pressure therapy, an absorbable barbed suture system and a cable ties system. The aim of this paper is to demonstrate how a combined application of these methods can reduce their respective individual disadvantages. Our combined method was tried in two patients, one with an open tibial fracture and the other who underwent ulnar nerve reparation. Both patients started exhibiting signs of compartment syndrome within 3 hrs after surgery. Firstly, absorbable barbed suture systems were positioned with the running intradermal technique. Following this the cable ties were inserted and the limb in question was placed in an elevated position. Complete closure of the patient's wounds was achieved within 2 weeks without complications. This result is a testament to the added benefit of a combination of these methods in comparison with the results they produce individually.
Assuntos
Síndromes Compartimentais , Fasciotomia , Humanos , Técnicas de Sutura , Transplante de Pele , Suturas , Síndromes Compartimentais/cirurgiaRESUMO
INTRODUCTION/OBJECTIVES: Minimal information exists regarding epicardial pacemaker (EP) implantation in pet ferrets (Mustela putorius furo). The objectives were to describe the indications, surgical technique, and outcome of EP implantation in ferrets for the treatment of advanced atrioventricular block (AVB). ANIMALS, MATERIALS, AND METHODS: Eight client-owned ferrets presenting to five veterinary referral centers. Signalment, physical exam findings, diagnostic tests, anesthesia protocols, surgical implantation techniques, postoperative treatment plans, and EP interrogations were reviewed. Intra- and postoperative, minor and major, and EP-related complications were established. Descriptive statistics were performed to report complication rates. Survival analyses were performed. RESULTS: All ferrets had advanced AVB: 3/8 had high-grade second-degree and 5/8 had third-degree. The primary clinical signs were collapse and weakness. Seven EP were implanted via a transdiaphragmatic approach and one via a left intercostal thoracotomy. Intraoperative complications occurred in 2/8 ferrets, both major. One ferret with severe comorbidities died during general anesthesia. Postoperative pacemaker-related complications were minor: inappropriate sinus beat sensing in 2/8 and occasional muscle fasciculations in 1/8. Two ferrets were alive at the time of manuscript submission, at 10 and 21 months postoperatively. The overall median survival time was 24 months. CONCLUSIONS: Implantation of EP was performed successfully in most ferrets for treatment of advanced AVB and was well tolerated. Ferrets with advanced AVB may experience resolution of clinical signs associated with their cardiac disease following EP implantation. Additional studies are warranted to investigate the effects of epicardial pacing on survival times in this species.
Assuntos
Bloqueio Atrioventricular , Cardiopatias , Marca-Passo Artificial , Animais , Bloqueio Atrioventricular/terapia , Bloqueio Atrioventricular/veterinária , Furões , Cardiopatias/veterinária , Marca-Passo Artificial/efeitos adversos , Marca-Passo Artificial/veterinária , Toracotomia/veterináriaRESUMO
After nearly a century of vaccination and six decades of drug therapy, tuberculosis (TB) kills more people annually than any other infectious disease. Substantial challenges to disease eradication remain among vulnerable and underserved populations. The Guarani-Kaiowá people are an indigenous population in Paraguay and the Brazilian state of Mato Grosso do Sul. This community, marginalized in Brazilian society, experiences severe poverty. Like other South American indigenous populations, their TB prevalence is high, but the disease has remained largely unstudied in their communities. Herein, Mycobacterium tuberculosis isolates from local clinics were whole genome sequenced, and a population genetic framework was generated. Phylogenetics show M. tuberculosis isolates in the Guarani-Kaiowá people cluster away from selected reference strains, suggesting divergence. Most cluster in a single group, further characterized as M. tuberculosis sublineage 4.3.3. Closer analysis of SNPs showed numerous variants across the genome, including in drug resistance-associated genes, and with many unique changes fixed in each group. We report that local M. tuberculosis strains have acquired unique polymorphisms in the Guarani-Kaiowá people, and drug resistance characterization is urgently needed to inform public health to ensure proper care and avoid further evolution and spread of drug-resistant TB.
Assuntos
Mycobacterium tuberculosis/genética , Polimorfismo de Nucleotídeo Único/genética , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia , Brasil , Farmacorresistência Bacteriana Múltipla/genética , Genótipo , Humanos , Filogenia , Grupos PopulacionaisRESUMO
After nearly a century of vaccination and six decades of drug therapy, tuberculosis (TB) kills more people annually than any other infectious disease. Substantial challenges to disease eradication remain among vulnerable and underserved populations. The Guarani-Kaiowá people are an indigenous population in Paraguay and the Brazilian state of Mato Grosso do Sul. This community, marginalized in Brazilian society, experiences severe poverty. Like other South American indigenous populations, their TB prevalence is high, but the disease has remained largely unstudied in their communities. Herein, Mycobacterium tuberculosis isolates from local clinics were whole genome sequenced, and a population genetic framework was generated. Phylogenetics show M. tuberculosis isolates in the Guarani-Kaiowá people cluster away from selected reference strains, suggesting divergence. Most cluster in a single group, further characterized as M. tuberculosis sublineage 4.3.3. Closer analysis of SNPs showed numerous variants across the genome, including in drug resistance-associated genes, and with many unique changes fixed in each group. We report that local M. tuberculosis strains have acquired unique polymorphisms in the Guarani-Kaiowá people, and drug resistance characterization is urgently needed to inform public health to ensure proper care and avoid further evolution and spread of drug-resistant TB
Assuntos
Humanos , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia , Polimorfismo de Nucleotídeo Único/genética , Mycobacterium tuberculosis/genética , Filogenia , Brasil , Farmacorresistência Bacteriana Múltipla/genética , Grupos Populacionais , GenótipoRESUMO
BACKGROUND: In fundoplication, mobilization of the distal oesophagus and proximal stomach is essential to obtain a sufficient tension-free intra-abdominal oesophageal length for creation of an efficient antireflux barrier. Most surgical literature and anatomical illustrations do not describe nerve branches running from the diaphragm to the stomach. After observing small nerve branches at laparoscopic fundoplication, penetrating the left crus of the diaphragm lateral to the hiatus and apparently running into the stomach, an anatomical cadaver study was undertaken to identify the origin and target organ of these nerves. METHODS: Fifty-three human cadavers (23 men, 30 women; age range 35-103 years) were dissected with special attention to the nerves that penetrate the left crus of the diaphragm. The entire course of these nerves was documented with standardized drawings and photos. RESULTS: Small nerve branches penetrating the diaphragm lateral to the left crus of the hiatus were found in 17 (32 per cent) of the 53 cadavers. In 14 of these 17 cadavers, one or two splanchnic nerve branches were identified, and in ten of the 17 the nerve branches were found to be phrenic nerves. In seven of these 17 cadavers, two different nerve branches were found and assigned to both splanchnic and phrenic nerves. CONCLUSION: Nerves penetrating the left crus with splanchnic origin or phrenic origin have been identified. Their function remains unclear and their relationship to postfundoplication symptoms remains to be determined.
ANTECEDENTES: A la hora de realizar una fundoplicatura, la movilización del esófago distal y del estómago proximal es esencial para obtener una longitud de esófago intraabdominal suficiente y sin tensión para crear una barrera antirreflujo eficiente. La mayoría de la literatura quirúrgica y de las ilustraciones anatómicas no describen unas ramas nerviosas que discurren desde el diafragma al estómago. Tras observar pequeñas ramas nerviosas durante la realización de una fundoplicatura laparoscópica que penetran la crura izquierda del diafragma lateral al hiato y que aparentemente discurren hacia el estómago, se llevó a cabo un estudio anatómico en cadáver para identificar el origen y el órgano diana de estos nervios. MÉTODOS: Se diseccionaron 53 cadáveres humanos (23 varones, 30 mujeres, rango de edad: 35-103 años) con especial atención hacia los nervios que penetran la crura izquierda del diafragma. Se documentó el recorrido completo de estos nervios con fotos y dibujos de una forma estandarizada. RESULTADOS: En 17 (32%) de 53 cadáveres se hallaron pequeñas ramas nerviosas que penetraban el diafragma lateral a la crura izquierda del hiato. En 14 cadáveres (de los 17) se identificaron una o dos ramas nerviosas esplácnicas, y en 10 de los 17 cadáveres las ramas nerviosas que se hallaron resultaron ser nervios frénicos. En 7 de estos 17 cadáveres, se hallaron dos ramas nerviosas diferentes y se asignaron a ambos nervios, esplácnicos y frénicos. CONCLUSIÓN: Se han identificado los nervios que penetran la crura izquierda con un origen esplácnico y frénico. Sus funciones están por aclarar, así como su relación con los síntomas que aparecen tras la fundoplicatura.
Assuntos
Diafragma/anatomia & histologia , Junção Esofagogástrica/anatomia & histologia , Fundoplicatura/métodos , Nervo Frênico/anatomia & histologia , Nervos Esplâncnicos/anatomia & histologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Cadáver , Esofagoplastia , Feminino , Humanos , Laparoscopia , Masculino , Pessoa de Meia-IdadeAssuntos
Percepção de Movimento , Percepção do Tato , Adulto , Viés , Humanos , Modelos EstatísticosRESUMO
The clinical significance of anti-neuronal antibodies for psychiatric disorders is controversial. We investigated if a positive anti-neuronal antibody status at admission to acute psychiatric inpatient care was associated with a more severe neuropsychiatric phenotype and more frequent abnormalities during clinical work-up three years later. Patients admitted to acute psychiatric inpatient care who tested positive for N-methyl-D-aspartate receptor (NMDAR), contactin-associated protein 2 (CASPR2) and/or glutamic acid decarboxylase 65 (GAD65) antibodies (n = 24) were age - and sex matched with antibody-negative patients (1:2) from the same cohort (n = 48). All patients were invited to follow-up including psychometric testing (e.g. Symptom Checklist-90-Revised), serum and cerebrospinal fluid (CSF) sampling, EEG and 3 T brain MRI. Twelve antibody-positive (ab+) and 26 antibody-negative (ab-) patients consented to follow-up. Ab+ patients had more severe symptoms of depression (p = 0.03), psychoticism (p = 0.04) and agitation (p = 0.001) compared to ab- patients. There were no differences in CSF analysis (n = 6 ab+/12 ab-), EEG (n = 7 ab+/19 ab-) or brain MRI (n = 7 ab+/17 ab-) between the groups. In conclusion, anti-neuronal ab+ status during index admission was associated with more severe symptoms of depression, psychoticism and agitation at three-year follow-up. This supports the hypothesis that anti-neuronal antibodies may be of clinical significance in a subgroup of psychiatric patients.
Assuntos
Autoanticorpos/sangue , Glutamato Descarboxilase/imunologia , Proteínas de Membrana/imunologia , Transtornos Mentais/sangue , Transtornos Mentais/imunologia , Proteínas do Tecido Nervoso/imunologia , Receptores de N-Metil-D-Aspartato/imunologia , Doença Aguda , Adulto , Idoso , Agressão , Depressão/sangue , Feminino , Seguimentos , Hostilidade , Humanos , Masculino , Transtornos Mentais/líquido cefalorraquidiano , Pessoa de Meia-Idade , Estudos Prospectivos , Agitação Psicomotora/sangueAssuntos
Haplótipos , Neoplasias Hematológicas/genética , Janus Quinase 2/genética , Modelos Genéticos , Mutação de Sentido Incorreto , Transtornos Mieloproliferativos/genética , Proteínas de Neoplasias/genética , Substituição de Aminoácidos , Feminino , Neoplasias Hematológicas/enzimologia , Humanos , Janus Quinase 2/metabolismo , Masculino , Transtornos Mieloproliferativos/enzimologiaRESUMO
When picking up objects using a pinch grip, there are usually numerous places at which one could place the thumb and index finger. Yet, people seem to consistently place them at or close to the centre of mass (COM), presumably to minimize torque and therefore the required grip force. People also prefer to grasp objects by parallel surfaces and ones with higher friction coefficients (rough surfaces), to prevent the object from slipping when they lift it. Here, we examine the trade-off between friction and COM. Participants were asked to grasp and lift aluminium bars of which one end was polished and therefore smooth and the other was rough. Their finger positions were recorded to determine how they grasped the objects. The bars were oriented horizontally in the frontal plane, with the centre aligned with the participants' body midline. The bars varied in the horizontal offset between the COM and the edge of the rough region. The offset could be 0, 1 or 2 cm. We expected participants to grasp closer to the rough area than the centre of the bar. Completely rough bars and completely smooth bars served as control conditions. The slipperiness of the surface that was grasped affected the height of the grasping points, indicating that participants adjusted their grasping behaviour to the slipperiness of the surface. However, the tendency to grasp closer to the rough area was minimal. This shows that the judged COM largely determines how an object is grasped. Friction has very limited influence.
Assuntos
Fenômenos Biomecânicos/fisiologia , Dedos/fisiologia , Atividade Motora/fisiologia , Desempenho Psicomotor/fisiologia , Adulto , Feminino , Humanos , Masculino , Adulto JovemRESUMO
Urban runoff is known to transport a significant pollutant load consisting of e.g. heavy metals, salts and hydrocarbons. Interactions between solid and dissolved compounds, proper understanding of particle size distribution, dissolved pollutant fractions and seasonal variations is crucial for the selection and development of appropriate road runoff treatment devices. Road runoff at an arterial road in Augsburg, Germany, has been studied for 3.5 years. A strong seasonal variation was observed, with increased heavy metal concentrations with doubled and tripled median concentrations for heavy metals during the cold season. Correlation analysis showed that de-icing salt is not the only factor responsible for increased pollutant concentrations in winter. During the cold period, the fraction of dissolved metals was lower compared to the warm season. In road dust, the highest metal concentrations were measured for fine particles. Metals in road runoff were found to show a significant correlation to fine particles SS63 (<63 µm). Therefore, it is debatable whether treatment devices only implementing sedimentation processes provide sufficient removal rates.
Assuntos
Tamanho da Partícula , Material Particulado/análise , Estações do Ano , Meios de Transporte , Poluentes Químicos da Água/análise , Cloretos/análise , Condutividade Elétrica , Alemanha , Metais Pesados/análiseRESUMO
Cattle temperament is a complex trait, and molecular studies aimed at defining this trait are scarce. We used an interaction networks approach to identify new genes (interacting genes) and to estimate their effects and those of 19 dopamine- and serotonin-related genes on the temperament traits of Charolais cattle. The genes proopiomelanocortin (POMC), neuropeptide Y (NPY), solute carrier family 18, member 2 (SLC18A2) and FBJ murine osteosarcoma viral oncogene homologue (FOSFBJ) were identified as new candidates. Their potential to be associated with temperament was estimated according to their reported biological activities, which included interactions with neural activity, receptor function, targeting or synthesis of neurotransmitters and association with behaviour. Pen score (PS) and exit velocity (EV) measures were determined from 412 Charolais cows to calculate their temperament score (TS). Based on the TS, calm (n = 55; TS, 1.09 ± 0.33) and temperamental (n = 58; TS, 2.27 ± 0.639) cows were selected and genotyped using a 248 single-nucleotide variation (SNV) panel. Of the 248 variations in the panel, only 151 were confirmed to be polymorphic (single-nucleotide polymorphisms; SNPs) in the tested population. Single-marker association analyses between genotypes and temperament measures (EV, PS and/or TS) indicated significant associations of six SNPs from four candidate genes. The markers rs109576799 and rs43696138, located in the DRD3 and HTR2A genes, respectively, were significantly associated with both EV and TS traits. Four markers, rs110365063 and rs137756569 from the POMC gene and rs110365063 and rs135155082 located in SLC18A2 and DRD2, respectively, were associated with PS. The variant rs110365063 located in bovine SLC18A2 causes a change in the amino acid sequence from Ala to Thr. Further studies are needed to confirm the association of genetic profile with cattle temperament; however, our study represents important progress in understanding the regulation of cattle temperament by different genes with divergent functions.
Assuntos
Bovinos/genética , Dopamina/genética , Epistasia Genética , Serotonina/genética , Temperamento , Animais , Comportamento Animal , Feminino , Genótipo , Polimorfismo de Nucleotídeo ÚnicoRESUMO
Reactivation of persistent human adenoviruses (HAdVs) is associated with high morbidity and mortality in paediatric haematopoietic stem cell transplant (HSCT) recipients. Although invasive HAdV infections mainly arise from the gastrointestinal (GI) tract, the specific sites of HAdV persistence are not well characterised. We prospectively screened biopsies from 143 non-HSCT paediatric patients undergoing GI endoscopy and monitored serial stool specimens from 148 paediatric HSCT recipients for the presence of HAdV by real-time PCR. Persistence of HAdV in the GI tract was identified in 31% of children, with the highest prevalence in the terminal ileum. In situ hybridisation and immunohistochemistry identified HAdV persistence in lymphoid cells of the lamina propria, whereas biopsies from five transplant recipients revealed high numbers of replicating HAdV in intestinal epithelial cells. The prevalence of HAdV species, the frequencies of persistence in the GI tract and reactivations post transplant indicated a correlation of intestinal HAdV shedding pre-transplant with high risk of invasive infection. HAdV persistence in the GI tract is a likely origin of infectious complications in immunocompromised children. Intestinal lymphocytes represent a reservoir for HAdV persistence and reactivation, whereas the intestinal epithelium is the main site of viral proliferation preceding dissemination. The findings have important implications for assessing the risk of life-threatening invasive HAdV infections.
Assuntos
Adenovírus Humanos/isolamento & purificação , Adenovírus Humanos/fisiologia , Trato Gastrointestinal/virologia , Ativação Viral , Infecções por Adenoviridae , Adolescente , Biópsia , Criança , Pré-Escolar , Fezes/virologia , Feminino , Transplante de Células-Tronco Hematopoéticas , Humanos , Hospedeiro Imunocomprometido , Lactente , Mucosa Intestinal/virologia , Linfócitos/virologia , Masculino , Estudos Prospectivos , Reação em Cadeia da Polimerase em Tempo Real , Adulto JovemRESUMO
AIM: Nerve-sparing surgery during laparoscopic rectal mobilization is still limited by anatomical constraints such as obesity, the narrowness of the male pelvis, an ultra low rectal cancer or all of these. The transanal approach for total mesorectal excision has overcome the shortcomings of limited access to the rectal 'no-man's land' close to the pelvic floor. The aim of this anatomical study was to define a roadmap of anatomical landmarks for the caudal to cephalic approach so as to standardize nerve-sparing rectal mobilization procedures. METHOD: Macroscopic dissections of the pelvis in a caudal to cephalic direction were performed in eight alcohol-glycerol embalmed cadavers. A roadmap of anatomical landmarks was created at different levels of section to demonstrate the sites of nerve injury. RESULTS: Extrinsic autonomic nerves to the urogenital organs and the internal sphincter muscle are closely adjacent to the lowest portion of the rectum above the pelvic diaphragm. CONCLUSION: This anatomical guide for the pelvic surgeon should facilitate a safe and nerve-sparing dissection of the mesorectal plane with a meticulous overview of the lowest autonomic nerve fibres. New anatomical insights by a 'caudal to cephalic' approach to the 'no-man's land' should help overcome anatomical constraints of a narrow, obese and male pelvis during rectal mobilization procedures.
Assuntos
Pontos de Referência Anatômicos/anatomia & histologia , Sistema Nervoso Autônomo/anatomia & histologia , Diafragma da Pelve/inervação , Reto/inervação , Cirurgia Endoscópica Transanal/métodos , Idoso , Idoso de 80 Anos ou mais , Vias Autônomas , Cadáver , Dissecação/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Diafragma da Pelve/cirurgia , Reto/cirurgiaRESUMO
Because muscle torques counteracting gravity vary systematically during a movement of the arm, it has been suggested that torque differences that occur during a movement provide important information for judging the distance moved away from the body. To test this suggestion, we examined whether external vertical forces applied to the hand (and the torque differences due to these forces) influence proprioception. In a first experiment, the added vertical forces were constant, resulting in a change in torque that was proportional to the gravitational torque, as when holding an object in your hand. This did not affect proprioception. In a second experiment, gradient force fields were used to dramatically change the torque differences. Again, no effect on proprioception was found. Thus, vertical forces caused by hand-held objects do not play an important role in judging the position or movement of the hand.
Assuntos
Mãos/fisiologia , Movimento/fisiologia , Propriocepção/fisiologia , Adulto , Feminino , Humanos , Masculino , Músculo Esquelético/fisiologia , Estimulação Luminosa , Torque , Adulto JovemRESUMO
To grasp an object one needs to determine suitable positions on its surface for placing the digits and to move the digits to those positions. If the object is displaced during a reach-to-grasp movement, the digit movements are quickly adjusted. Do these fast adjustments only guide the digits to previously chosen positions on the surface of the object, or is the choice of contact points also constantly reconsidered? Subjects grasped a ball or a cube that sometimes rotated briefly when the digits started moving. The digits followed the rotation within 115 ms. When the object was a ball, subjects quickly counteracted the initial following response by reconsidering their choice of grasping points so that the digits ended at different positions on the rotated surface of the ball, and the ball was grasped with the preferred orientation of the hand. When the object was a cube, subjects sometimes counteracted the initial following response to grasp the cube by a different pair of sides. This altered choice of grasping points was evident within â¼160 ms of rotation onset, which is shorter than regular reaction times.
Assuntos
Dedos/fisiologia , Força da Mão , Adulto , Feminino , Dedos/inervação , Humanos , Masculino , Destreza Motora , Movimento , Tempo de Reação , RotaçãoRESUMO
Does the nervous system continuously realign the senses so that objects are seen and felt in the same place? Conflicting answers to this question have been given. Research imposing a sensory mismatch has provided evidence that the nervous system realigns the senses to reduce the mismatch. Other studies have shown that when subjects point with the unseen hand to visual targets, their end points show visual-proprioceptive biases that do not disappear after episodes of visual feedback. These biases are indicative of intersensory mismatches that the nervous system does not align for. Here, we directly compare how the nervous system deals with natural and imposed mismatches. Subjects moved a hand-held cube to virtual cubes appearing at pseudorandom locations in three-dimensional space. We alternated blocks in which subjects moved without visual feedback of the hand with feedback blocks in which we rendered a cube representing the hand-held cube. In feedback blocks, we rotated the visual feedback by 5° relative to the subject's head, creating an imposed mismatch between vision and proprioception on top of any natural mismatches. Realignment occurred quickly but was incomplete. We found more realignment to imposed mismatches than to natural mismatches. We propose that this difference is related to the way in which the visual information changed when subjects entered the experiment: the imposed mismatches were different from the mismatch in daily life, so alignment started from scratch, whereas the natural mismatches were not imposed by the experimenter, so subjects are likely to have entered the experiment partly aligned.
Assuntos
Retroalimentação Psicológica , Desempenho Psicomotor , Feminino , Humanos , Masculino , Estimulação Luminosa , Propriocepção/fisiologia , Visão Ocular/fisiologiaRESUMO
Dogs can be infected by a wide range of Bartonella spp., but limited studies have been conducted in tropical urban and rural dog populations. We aimed to determine Bartonella antibody prevalence in 455 domestic dogs from four tropical countries and detect Bartonella DNA in a subset of these dogs. Bartonella antibodies were detected in 38 (8·3%) dogs, including 26 (10·1%) from Colombia, nine (7·6%) from Brazil, three (5·1%) from Sri Lanka and none from Vietnam. DNA extraction was performed for 26 (63%) of the 41 seropositive and 10 seronegative dogs. Four seropositive dogs were PCR positive, including two Colombian dogs, infected with B. rochalimae and B. vinsonii subsp. berkhoffii, and two Sri Lankan dogs harbouring sequences identical to strain HMD described in dogs from Italy and Greece. This is the first detection of Bartonella infection in dogs from Colombia and Sri Lanka and identification of Bartonella strain HMD from Asia.
Assuntos
Anticorpos Antibacterianos/sangue , Infecções por Bartonella/veterinária , Bartonella/isolamento & purificação , Doenças do Cão/epidemiologia , Animais , Bartonella/genética , Bartonella/imunologia , Infecções por Bartonella/epidemiologia , Cães , Reação em Cadeia da Polimerase , Estudos Soroepidemiológicos , Clima TropicalRESUMO
To grasp an object the digits need to be placed at suitable positions on its surface. The selection of such grasping points depends on several factors. Here the authors examined whether being able to see 1 of the selected grasping points is such a factor. Subjects grasped large cylinders or oriented blocks that would normally be grasped with the thumb continuously visible and the final part of the index finger's trajectory occluded by the object in question. An opaque screen that hid the thumb's usual grasping point was used to examine whether individuals would choose a grip that was oriented differently to maintain vision of the thumb's grasping point. A transparent screen was used as a control. Occluding the thumb's grasping point made subjects move more carefully (adopting a larger grip aperture) and choose a slightly different grip orientation. However, the change in grip orientation was much too small to keep the thumb visible. The authors conclude that humans do not particularly aim for visible grasping points.
Assuntos
Força da Mão/fisiologia , Desempenho Psicomotor/fisiologia , Percepção Espacial/fisiologia , Percepção Visual/fisiologia , Adulto , Interpretação Estatística de Dados , Feminino , Dedos/fisiologia , Testa/fisiologia , Mãos/fisiologia , Humanos , Masculino , Movimento , Postura/fisiologia , Polegar/fisiologia , Adulto JovemRESUMO
The selection of grasping points, the positions at which the digits make contact with an object's surface in order to pick it up, depends on several factors. In this study, we examined the influence of obstacles on the selection of grasping points. Subjects reached to grasp a sphere placed on a table. Obstacles were placed either near the anticipated grasping points or near the anticipated elbow position at the time of contact with the object. In all cases, subjects adjusted the way they moved when there was an obstacle nearby, but only obstacles near the thumb had a consistent influence across subjects. In general, the influence of the obstacle increased as it was placed closer to the digit or elbow, rather than the subject grasping in a manner that would be appropriate for all conditions. This suggests that under these circumstances the configuration of the arm and hand at the moment of contact was a critical factor when selecting at which points to grasp the objects.
Assuntos
Percepção de Distância , Percepção de Forma , Força da Mão , Orientação , Desempenho Psicomotor , Adulto , Feminino , Humanos , Cinestesia , Masculino , Resolução de Problemas , Propriocepção , Tempo de ReaçãoRESUMO
BACKGROUND: Venous valves have been classified into parietal (PVs) and ostial valves (OVs). PVs are located within the lumen of veins, whereas the OVs are located directly at the confluence of two veins. In the common femoral vein (CFV), the most prominent PVs are the suprasaphenic and infrasaphenic valve. The terminal valve (often designated as 'valvule ostiale' in the relevant literature in French) defined as that lying between the orifice of the great saphenous vein (GSV) and the most proximal of the major superficial tributary veins and the preterminal valve represent the most important PVs in the GSV. While PVs are well studied, there is not much literature on the OVs of the superficial venous system, especially of the GSV. OBJECTIVE: In order to investigate the presence of OVs (defined strictly as valves located at the entrance of a tributary vein) in the GSV, we carried out studies on specimens obtained from bodies bequested to the Division of Clinical and Functional Anatomy of Innsbruck Medical University. METHODS: Ninety-eight specimens consisting of the CFV and the attached tributary veins including the GSV were investigated. RESULTS: In five of these (5.1%), a single-cusped OV, in six (6.1%) a two-cusped OV and in 10 (10.2%) remnants of an OV were identified. Thus, OVs do not seem to be primarily present in all GSVs. CONCLUSION: The distinction between PVs and OVs is not always clear in literature, and as a consequence misinterpretations may occur. Very often the terminal valve of the GSV, which is in fact a PV, is designated as an 'ostial valve'. In view of its widespread use, we suggest that the term 'ostial valve' together with its clear description be included in the consensus documents of the 'Union Internationale de Phlébologie'.