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Tests of an Algebraic Notation Calculator and a Reverse Polish Notation Calculator showed the latter to be superior in terms of calculation speed, particularly for subjects with a technical background. The differences measured were shown not to be due to differences in calculation speed of the calculators nor to differences in dexterity between the subjects.
This study describes a method for sizing mittens based upon an analysis of the user populations and the hand measurements of these users. New anatomically designed military mittens were developed according to the users' requirements and ergonomic and physiological requirements of dexterity and heat balance. A statistical study of anthropometrical hand measures of the intended users lead to the choice of hand length and hand circumference as the basis for a new sizing system. The mittens were tested in two sizes in large wear trials. These two sizes fitted well to the test group - i e, young conscripts. If the whole adult population is considered, probably two more sizes would be needed.
Required Clothing Insulation (IREQ) is a new thermal index submitted to the International Organisation for Standardisation (ISO) for discussion. It is designed to prevent general body cooling and is based on an analysis of heat exchanges. The thermal clothing insulation actually worn (lcl) is estimated using a new method, also submitted to ISO. IREQ of 54 workers exposed to artificial cold (air temperature between -30 degrees C and +10 degrees C) was compared with lcl actually worn by these workers. The results of the present study show that, on average, the workers choose accurately lcl they need if their IREQ is below and up to 1.5 clo. Moreover, these workers prefer to wear garments which provide them with thermal comfort. If IREQ of workers is higher than 1.5-2 clo (i e, workers exposed to -20 degrees C), it is difficult for them to increase their thermal insulation with additional garments. Although their lcl is not sufficient, there is no risk of gradual body cooling because of their continuous time exposure (CTE) which is shorter than the calculated Duration Limited Exposure (DLE). On the other hand, Wind Chill Index (WCI), which is proposed to prevent local cooling, is better adapted to prevent cold injuries than physiological thermal strain; for example, impairment of manual dexterity cannot be prevented with this index.
This study compares long-term effectiveness of traditional functional retraining (TFR) with neuromuscular retraining techniques (NRT) after cerebrovascular accident (CVA). Groups of post-CVA patients from two different rehabilitation programs were matched according to early prognostic indicators. In one program NRT was emphasized while in the other the emphasis was restricted to TFR of spontaneously acquired upper extremity dexterity. Follow-up was possible in 19 of the TFR group and 20 of the NRT group who survived eight months after CVA. At least eight months post-CVA patients/families completed a telephone questionnaire regarding current functional abilities. With the single exception of self-feeding, no statistically significant differences in skill levels were found. NRT patients showed a slightly greater independence in feeding than the patients in functional retraining. It was also noted that rehabilitation hospitalization was significantly longer in the NRT group (28.57 days vs 68.3 days). The reason for this is not clear. If choice of therapeutic techniques was a contributing factor to increased lengths of stay, however, this would have major cost/effectiveness implications for program planning.
In monkeys with a unilateral subtotal lesion of the bulbar pyramid, a partial recovery of manual dexterity occurred within 4-6 weeks. This recovery may have been due to sprouting of fibers from the intact pyramid into the partly denervated areas of the spinal gray matter. In order to test this hypothesis, small injections of radioamino acids were made in the precentral hand area of two experimental animals (3 and 18 months after pyramidotomy) and one normal control animal. The pattern of spinal labeling was analyzed in autoradiographs from the cervicothoracic segments. No statistically significant additional labeling was found in laminae VI-VIII where the majority of the ipsilateral corticospinal fibers terminate. However, in the monkey with a long survival time, many large perikarya, situated exclusively within lamina IX in segments C8 and T1, were labeled with aggregations of silver grains. On the basis of the position and size of these neurons we conclude that a postsynaptic labeling occurred selectively in those motoneurons which control hand movements and which were deprived from their contralateral pyramidal control. We tentatively suggest that such a labeling may reflect an influence of the (injected) ipsilateral cortex on these distal motoneurons via direct connections which are normally not observed in the intact monkey.
Skillful handling of a microsurgical needle holder is dependent not only on manual dexterity but also on the ergonomics of its design. This paper presents the design of a modified needle holder that makes it better suited to the atraumatic passage of a semi-circular needle through tissues.
We previously described the interleukin 3 (IL-3)-dependent cell line, M1-A5, which has both natural cytotoxic (NC) and suppressor cell activities, the latter of which is mediated, in part, by the release of two cytokines which activate suppressor cells from unprimed lymphoid precursor cells. In this study we have compared the M1-A5 cell line with four other IL-3-dependent cell lines to determine whether these dual activities are universally associated with IL-3 dependence and to test the hypothesis that there is a direct relationship between the cytotoxic and the suppressive activities. The cell lines tested were a bone marrow derived Dexter culture derived line (FDC-P1), two Moloney leukemia virus induced leukemias (DA-1 and DA-3), and a mast cell line (PT18(A17]. All lines were dependent on IL-3 for survival but FDC-P1, DA-1, and DA-3 showed varying degrees of short-term proliferation in granulocyte-macrophage colony stimulating factor (GM-CSF). The cell lines all expressed asialo GM1 and Ly-5 surface markers but differed with respect to other markers. DA-1 expressed MAC-1, FDC-P1 and DA-3 expressed Thy-1, and PT18(A17) expressed receptors for the Fc portion of IgE. The cell lines varied greatly in their cytotoxic activity against WEHI-164. FDC-P1, DA-1, and PT18(A17) had low NC activity. DA-3 had consistently high activity, greater than that seen with M1-A5 cells. However, none of the cell lines secreted constitutively a suppressor cell inducing factor (SIF). In addition, it was demonstrated that recombinant murine TNF did not activate suppressor cells capable of inhibiting antibody synthesis and that anti-TNF did not block SIF activity, thus suggesting that TNF contamination of the M1-A5 derived SIF preparation is not responsible for the induction of suppressor cells. We conclude that suppressor cell inducing factors are not universally secreted by IL-3-dependent cell lines, that there is no correlation between NC and SIF activity, and that the dual activities of M1-A5 cells are not mediated by TNF.
Neither lytic NK cells nor IL-2-responsive NK precursors were produced in myeloid (Dexter) long-term bone marrow cultures (LTBMC). However, when myeloid LTBMC were switched to lymphoid (Whitlock-Witte) conditions and reseeded ("recharged") with fresh bone marrow cells (BMC), nonadherent cells with NK lytic activity and NK 1.1+ phenotype were produced within 1-2 weeks without the addition of exogenous IL-2 to the cultures. NK- and T cell-depleted BMC proliferated extensively in switched cultures and in 2 weeks generated cells that lysed the NK target YAC-1 but not the LAK target P815. The presence of NK precursors in the cultures was confirmed by reculturing nonadherent cells harvested from recharged LTBMC in fresh medium containing 50 U rIL-2/ml. High levels of NK lytic activity were generated. Sequential expression of NK 1.1 and IL-2 responsiveness followed by lytic activity was demonstrated by harvesting cells early after recharge, prior to the appearance of lytic cells. Elimination of NK 1.1+ cells depleted the ability to respond to IL-2 in secondary culture. Our studies demonstrate that myeloid-to-lymphoid switched LTBMC support the proliferation and differentiation of NK lineage cells from their NK 1.1-, nonlytic progenitors in the absence of an exogenous source of growth factors.
Advances in the design of special cryobiomedical apparatus and a review of the trend of developments in the field of cryosurgery in China are discussed. The typical structure of two special cryoprobes for treatment deep in the body and the technology of designing these probes are presented in detail. Some cases which are treated successfully with the above cryoprobes will also be discussed. The experimental aspects of heat transfer in frozen tissue and of the temperature profiles both of a human brain during surgery and of the cryoprobe are described. Other improvements in the field of cryosurgical devices, e.g., four main ways of attaching freezing tips to cryoprobes during surgery and an LN2 transfer tube with high dexterity are also presented. Finally, the development of commercial cryosurgical apparatus in China is also discussed.
A haptic contact lens stimulator has been developed to allow monitoring of the visual evoked potential to flash stimulation during orbital surgery. The contact lens stimulator is fitted with a small plastic prism into which a fibre-optic cable is inserted at right angles to the axis of the contact lens. This allows both the stimulator and the fibre-optic to be permanently in place throughout orbital surgery without interfering with the surgeon's vision or dexterity. Using this technique continuous evoked potentials can be obtained allowing immediate feedback to the surgeon of any condition threatening the integrity of the optic nerve. The technique has now been used on over 20 eyes and is commercially available.
We report an adaptation to cultures of chicken bone marrow cells of the Dexter culture technique for obtaining long-term hemopoiesis in vitro. Cells were seeded in DMEM supplemented with fetal calf serum (20%) and hydrocortisone (10(-6) M) with or without chicken serum (1%). Cultures were incubated at 37 degrees C and fed every 2 weeks. An adherent cell layer composed of macrophages, fibroblasts, and adipocytes became established, over which hemopoietic cells formed foci and were released into the supernatant. Granulocytes and monocytes-macrophages differentiated in a constant proportion until Week 6, whereafter differentiation became progressively restricted to the monocytic lineage. As demonstrated by the generation of colony-forming cells, hemopoiesis was maintained for either 12 or 28 weeks.
Although often portrayed as something of a joke, injuries sustained in the setting-up and use of deck-chairs can have fairly serious consequences. Six patients who sustained finger injuries in some of London's Royal Parks during the Summer are presented together with data from the Department of Trade and Industry suggesting that, taken throughout the country as a whole, large numbers of injuries may be occurring. Notably, four of our patients were foreign tourists who may be less familiar with the traditional wooden folding deck-chair. Surprisingly no British Standards Institute (BSI) guidelines exist relating to deck-chair safety. These finger injuries can have marked morbidity if they involve victims who depend upon manual dexterity in their work or hobbies.
Twelve cases of galactorrhea in women with normal menstrual cycles who were radiologically free of any pituitary adenomas were investigated. Determinations were made for serum thyroid-stimulating hormone (TSH), T3 resin uptake (T3RU), total thyroxine by radioimmunoassay (T4), free thyroxine index (FT4I), norepinephrine, epinephrine, prolactin and urinary luteinizing hormone, total estrogens, pregnanediol and total catecholamines. Psychologic evaluation and assessment were also done using the Middlesex Hospital Questionnaire and the Eysenk, manual dexterity, Bender Gestalt and trial-making scales. Hypothyroidism associated with moderate hyperprolactinemia and anovulation were the main features in eight cases. Associated psychologic disturbances were reported. The other four cases showed significant elevations in serum epinephrine, norepinephrine and urinary total catecholamines with concomitant pathologic scales of anxiety and neuroticism. Thyroxine replacement and psychotherapy are recommended in the treatment of such cases.
Treatment of Dexter-type long-term bone marrow cultures with the antibiotic mycophenolic acid (MPA) eliminates all hemopoietic cells from the cultures, while a morphologically intact, adherent stromal cell layer is retained. The ability of these MPA treated stromal cell cultures to support long-term hemopoiesis was tested by seeding them with fresh bone marrow cells that had been passed through nylon wool. This procedure yields a relatively stromal cell depleted population of hemopoietic cells. An aliquot of 5 X 10(5) or 2.5 X 10(5) nylon wool passed bone marrow cells bearing the T6 chromosomal marker was seeded onto replicate MPA-treated stromal cell layers. The stromal cells stimulated the proliferation of the bone marrow cells, and nonadherent cells were present for up to 8 weeks of culture. Progenitors of granulocytes and macrophages (CFU-GM) were also present for this period of time despite weekly demi-depopulation, during culture feeding. Karyotypic analysis confirmed that the CFU-GM were derived from the reseeded population. Nylon wool-passed bone marrow cells seeded alone into empty flasks under identical conditions did not survive past 1 week. Cells from the reseeded cultures were also tested for early myeloid precursors (CFU-S) and injected into immunodeficient CBA/N mice to test for the presence of primitive B cell precursors. CFU-S were present in mice killed 11 days following injection of cells, and high levels of B cell colony-forming units (CFU-B) were present in mice 4 weeks post reconstitution. Further studies demonstrated that factors present in medium conditioned by the stromal cells could support the growth of CFU-GM. These data indicate that treatment of long-term bone marrow cultures with MPA results in a population of functional stromal cells.
This report describes a colony assay system, based on methods used to grow myeloid precursors in semisolid medium, in which B cell progenitors can be grown. The formation of these B cell progenitor colonies is dependent upon soluble mediators from a stromal cell line known to support B lymphopoiesis. In initial experiments a double layer culture system was employed in which target cells in methylcellulose medium were separated from an adherent layer of S17 stromal cells by an agar interface. Target cells were harvested from Dexter type long-term bone marrow cultures at a time after transfer to the lymphoid Whitlock-Witte conditions, when myeloid progenitors were depleted and mature B cells had not yet appeared. On day 15 of culture a colony could be identified that contained several hundred tightly clustered lymphoid cells. There was a linear relationship between the number of cells plated and the number of colonies that developed. Identically appearing colonies were also observed in agar using fresh bone marrow cells as targets with either an underlayer of S17 cells or S17 conditioned medium to potentiate colony growth. Lymphoid colonies derived from fresh bone marrow appeared on days 6 and 14 of growth. A proportion of the cells from the fresh or cultured marrow derived colonies expressed the B220 antigen and cytoplasmic mu heavy chains, but surface IgM was never observed. Cell depletion experiments on antibody coated plates demonstrated the colony forming unit to be B220 antigen positive, surface IgM negative, and replating experiments indicated the colonies were lymphoid restricted in their differentiative potential.
Parallel pin retention is traditional in restorative dentistry and provides a conservative approach to removal of tooth structure, including restorations with supragingival margins. However, the question of whether pinhole preparations should be performed freehand or by using a paralleling instrument has been frequently discussed. This investigation compared the precision of freehand and instrument-guided preparations under simulated clinical conditions. The results indicated that guided preparations provided better paralleling precision than freehand preparations, but did not exclude success by the freehand approach. Both instrument preparation and freehand preparation were influenced by the dentist's dexterity and technical capability.
Attention is drawn to certain disorders of posture and movement such as kneeling, turning around in the recumbent position, arising and walking which form a separate group of motor disabilities in Parkinson patients. Levodopa therapy is far less effective for these axial motor abnormalities than for hypokinesia, tremor, rigidity and manual dexterity. Inappropriate function of the axial musculature leads to debilitating situations. It is argued that the disordered axial movements are not the result of an akinetic mechanism but share the criteria applied to apraxic phenomena and the term axial apraxia is proposed. Thus far axial apraxia has resisted conventional physiotherapeutic treatment, but some patients overcome their apraxic disability using alternative motor strategies.
Imitation of meaningless gestures was examined in patients with left brain damage (LBD), right brain damage (RBD) and controls. In addition to imitation on the own body, patients were asked to replicate the gestures on a life-sized mannikin. Manual dexterity was assessed by manipulation of beads, and general visuospatial abilities by block-design. LBD patients who displayed apraxia when imitating gestures on their own bodies scored dramatically worse than any other group when imitation was assessed on the mannikin. By contrast, on block-design and manipulation of beads patients with RBD were inferior not only to LBD patients without apraxia but also to apractic patients. Analysis of CT scans revealed that apraxia occurred with frontal, parietal and deep lesions, and that the impairment on the manipulation of the mannikin was present regardless of lesion site. The results support the contention that the basic deficit underlying impaired imitation of meaningless gestures in apraxia is to be sought at a conceptual level. Possibly, patients with apraxia are not able to evoke and represent conceptual knowledge about the human body which is necessary for performing the apparently simple task of imitating gestures.