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Biomedical subjects

J H Nicholson

Publications and source records attributed to J H Nicholson.

7 recordsLinked to original sources
PubMed2001

Assessment of upper-limb function and movement in children with cerebral palsy wearing lycra garments.

It has recently been suggested that lycra garments are helpful for children with cerebral palsy (CP). Twelve children, with athetosis, ataxia, and spasticity, were fitted with lycra garments (Kendall-Camp UK Ltd). Scores on the Paediatric Evaluation of Disability Inventory (PEDI) scales were determined before and after wearing the garment for at least 6 hours a day for 6 weeks. Five children with motor problems representative of the whole group were investigated during a reach-and-grasp task by kinematic motion analysis; reflective markers were used with and without the garment. Carers were given a questionnaire concerning the practicalities of using the garments. All 12 children made improvements in at least one of the functional scales of the PEDI, and scores for the whole group showed significant gains (Wilcoxon chi2 test, self-help p<0.01; mobility p<0.5; social p<0.1). These changes were usually slight, although noticed by carers. Six children made gains of at least one scale of the caregiver assistance scores, two of the children showed losses (due to difficulties removing the garment for toileting), and four showed no change. Motion analysis indicated that (1) two children with athetosis had improved proximal stability in sitting and in smoothness of arm movements, (2) one child with ataxia had improved in proximal and distal stability, and (3) two children with spasticity had more jerky movements, although one improved in proximal stability. All children had problems in wearing the garments, including problems with toileting and incontinence of urine; the parents of only one child wanted to continue using it. Results suggest that the functional benefit of lycra garments for children with CP is mainly due to improvements in proximal stability but this should be weighed against the inconvenience and loss of independence.

Activities of Daily Living↗
PubMed1998

Morphometric discrimination of melanoma in situ of sun-damaged skin from chronically sun-damaged skin.

BACKGROUND: The histologic discrimination of melanoma in situ of sun-damaged skin (MIS) from chronically sun-damaged skin (SDS) can sometimes be difficult using accepted criteria. OBJECTIVE: We evaluated these entities by means of morphometry and multifactorial analysis. METHODS: We measured the number and area of melanocyte nuclei, melanocyte nucleoli, stratum spinosum keratinocyte nuclei, and papillary dermal lymphocyte nuclei from hematoxylin-eosin-stained slides representing 38 cases of MIS and 18 cases of SDS matched for age, sex, and site with a high-resolution digital imaging and analysis system. RESULTS: Multiple logistic regression analysis correctly classified 100% of the cases using the number of melanocytes per 0.5 mm and the maximum melanocyte nuclear area divided by the maximum keratinocyte nuclear area. The strongest results were achieved measuring approximately 1 mm of epidermis. CONCLUSION: Morphometry and multifactorial analysis can distinguish MIS from SDS. Morphometric analysis of melanocytic proliferations may be useful at the margins of surgical resections.

Aged↗
PubMed1991

DAPI as a useful stain for nuclear quantitation.

A simple-to-use fluorescent stain, 4',6-diamidino-2-phenylindole (DAPI), visualizes nuclear DNA in both living and fixed cells. DAPI staining was used to determine the number of nuclei and to assess gross cell morphology. Following light microscopic analyses, the stained cells were processed for electron microscopy. Cells stained with DAPI showed no ultrastructural changes compared to the appearance of cells not stained with DAPI. DAPI staining allows multiple use of cells eliminating the need for duplicate samples.

Animals↗
PubMed1988

A new method for the comprehensive automatic morphologic image analysis of Langerhans cells.

Standard techniques used to study Langerhans cell (LC) populations are tedious and time-consuming. We developed a rapid and comprehensive method to evaluate LC using automatic digital image analysis. Human epidermal sheets were stained with OKT6 monoclonal antibody and evaluated on an IBAS 2000 computerized automatic digital image analysis system. The fields were imaged on a Photomicroscope I using a high-resolution monochrome video camera. Each field was digitized, normalized, and filtered. The LC were discriminated by density; each field was interactively edited to separate overlapping cells and to bridge small gaps in the dendrites. The discriminated binary image of the LC was measured for number of cells per field, total area of individual cells per field, and percent of the field occupied by LC. The cell bodies were then separately discriminated and subtracted from the thinned cell image to allow a separate measurement of number and length of dendrites per cell. Finally, the binary cell image in a reference section was dilated to occupy approximately the total field area. This degree of dilation was then applied to all subjects to give the "area of influence." This methodology provides a rapid and comprehensive tool for the evaluation of LC.

Autoanalysis↗
PubMed1984

Effects of substituted dithiocarbamates on the testicular toxicity of cadmium.

Five substituted dithiocarbamates were evaluated for effectiveness in protecting mouse testes following administration of an LD100 dose of CdCl2 X 2.5 H2O (Cd). Toxicologic responses were assessed by light microscopic, electron microscopic, and computerized image analysis techniques. Diethyldithiocarbamate (DDTC) was the most effective antagonist. N-ethyl-N-hydroxyethyldithiocarbamate (EHDC), N-methyl-N-hydroxyethyldithiocarbamate (MHDC), and dimethyldithiocarbamate (DMDC) were moderately to minimally effective, while di-(hydroxyethyl)dithiocarbamate (DHDC) afforded no protection. Degenerative changes increased progressively in severity as the time interval between administration of Cd and DDTC was increased, but remained minimal when DDTC was given as late as two hours after Cd.

Animals↗
PubMedDate not supplied

Automatic quantitation of cell growth and determination of mitotic index using DAPI nuclear staining.

The growth rate of primary tumors and derived cell lines is an important identifying trademark to researchers studying the growth and differentiation of pediatric neoplasms. For the in vivo tumor specimen, the mitotic index is utilized to assess growth potential while, in vitro, the determination of the growth curve and doubling time of the cells is employed. Because of the importance of these parameters this laboratory has developed a technique for the simultaneous determination of cell number and mitotic index for adherent cultured cells, as well as solid tumors, using the polycationic dye DAPI (4',6-diamino-2-phenylindole). DAPI, when bound to nuclear DNA, fluoresces, and this property has been utilized to develop an image analysis based technique to determine cell number automatically based on gray scale discrimination. In addition, DAPI staining clearly delineates mitotic figures and this has allowed the simultaneous manual determination of mitotic index for each automatic cell count. This technique was first tested using four different human cell lines and was shown to determine cell growth and mitotic index simultaneously. Lastly, employing an atypical mesoblastic nephroma, it was shown that the mitotic index of the primary tumor could easily be obtained and compared to both the mitotic index of tumor heterotransplant in nude mice and the mitotic index of the tumor-derived cell culture. This technique should be useful in studies assessing the effects of various factors on the growth of adherent cultured cells as well as the accurate determination of the mitotic index in solid tumors.

Cell Count↗