Development of a new haptic perception instrument: a pilot study / Desenvolvimento de um novo instrumento de avaliação da percepção háptica: um estudo piloto

ABSTRACT Objective Hand sensory tests do not consider distinct physiological receptors, nor detect normal range variations concerning developmental or pathological changes. We developed an instrument with a set of tests with timing and scoring for assessing haptic perception, which is the interaction between sensory and motor systems, in surfaces exploration, by moving hands. Method Firstly, group meetings were set for test/manual conception and materials testing. The test/manual were submitted to 30 reviewers in 3 stages (10 reviewers on each stage). Results The Hand Haptic Perception Instrument (HHPI) evaluates hand sensorimotor performance on six domains: depression, elevation, texture, compressibility, weight (barognosis) and form perception. Each domain requires specific materials. Score ranges from 0 to 57, being 0 the worst rating. Conclusion This methodological process allowed the development of six domains and instructions to assess haptic perception. This version of HHPI is a pilot model. Further studies will determine reliability and normality ranges.

RESUMO Objetivo Testes de sensibilidade manual não consideram receptores fisiológicos distintos, tampouco variações do desenvolvimento normal ou patológico. Desenvolvemos um instrumento, com pontuação e tempo de desempenho, para avaliar percepção háptica, que é a interação sensório-motora na exploração de superfícies, pelo movimento das mãos. Método Reuniões de grupo foram estabelecidas para desenvolver os testes/ manual e testar materiais. O instrumento e seu manual foram submetidos a 30 revisores, em 3 estágios (com 10 revisores em cada estágio). Resultados O instrumento de avaliação da percepção háptica manual (IAPHM) avalia o desempenho sensório-motor da mão em seis domínios: depressão, elevação, textura, compressibilidade, peso (barognosia) e percepção de forma. Cada domínio requer materiais específicos. A pontuação vai de 0 a 57, sendo 0 a pior pontuação. Conclusão Esse método permitiu o desenvolvimento do instrumento para avaliar percepção háptica. Essa versão do IAPHM é um modelo piloto. Estudos futuros determinarão confiabilidade e variações de normalidade.

The Nerve-dependency of Merkel Cell Proliferation in Cultured Human Fetal Glabrous Skin

Merkel cells are thought to function as slowly adapting mechanoreceptors and are known as targets for sensory nerves. However, the nerve-dependency of Merkel cells remains controversial. In this respect, some investigators have found interregional differences between hairy and glabrous skin and others have shown intraregional differences within denervated rat touch domes. Differences between species have also been reported. This study was performed to determine whether Merkel cells proliferate in vitro in the absence of the systemic factors, blood vessels and the intact nerves in human skin. Suspension organ culture was performed using fetal digits to investigate their in vitro proliferation. Merkel cells and cutaneous nerves were identified using antibodies to cytokeratin 20 and protein gene product 9.5 (PGP 9.5), respectively. Fetal digits of 56-82 day gestational age were cultured in serum free medium in a high O2 (45%) environment. Tissues were harvested before starting culture (D0) and 1,4,7,14, 28d after culture. Merkel cells were observed in the volar pads and dorsal nail matrices at D0. After 28d of suspension organ culture, digits looked healthy structurally and the number of Merkel cells had increased. However, PGP 9.5-immunoreactive nerves were markedly diminished after 1 day of culture and almost disappeared after 4 days. Merkel cell proliferation in vitro suggested that Merkel cell development is probably nerve-independent in human fetal glabrous skin.