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PubMed1995

Neurobehavioral effects of acute and chronic mixed-solvent exposure in the screen printing industry.

This 2-year prospective study examined the neurobehavioral effects of acute and chronic exposure to mixed solvents in workers in a screen printing business. A total of 30 subjects participated in the study in two field testings over a 12 month period. Each subject completed a detailed medical and occupational questionnaire, had a neurological examination, and underwent a battery of neuropsychological tests. Industrial hygiene investigation identified the following chemical exposures as present: toluene, methyl ethyl ketone, mineral spirits, beta-ether, methylene chloride, and acetic acid. Different departments and jobs had varying degrees of exposure to these chemicals, the highest exposures being in the ink mix area and the screen washroom area. However, all exposure levels were below recommended threshold limit values. Persons categorized as having higher acute exposure demonstrated significantly impaired test performance on tasks involving manual dexterity, visual memory, and mood. Those with higher chronic exposure demonstrated significantly poorer performance on visual memory tasks and mood. Results suggest that the mixed solvents used in the screen printing industry have an effect on central nervous system functioning in the absence of obvious clinical disease.

Adult↗
PubMed1994

Neurobehavioral characteristics of CGG amplification status in fragile X females.

Neurobehavioral correlates of CGG amplification were studied in 17 nonretarded adult female carriers of fragile X syndrome. The results revealed a significant relationship between IQ and the number of CGG repeats in the 5' untranslated region of the FMR1 gene. Women with a full mutation (> 200 CGG repeats) scored below average in IQ, visual-spatial perception, visual-spatial organization, and executive function. There were no differences in fine motor dexterity or memory as a function of CGG amplification status. A history of major depressive disorder was identified in 71% of the sample, but incidence of depression was not associated with the degree of CGG amplification. Schizotypal features were noted in 18%. No intellectual or neuropsychological deficit was found in women with a premutation (< 200 CGG repeats). Decrements in IQ, visual-spatial perception, and executive function appear to arise as a consequence of the CGG amplification.

Adult↗
PubMed1982

The functional morphology of caudal vertebrae in New World monkeys.

New World monkeys vary considerably in the manner and degree to which they use their tails. There ought to arise a corresponding variation in the stresses on caudal vertebrae. Consequently, different behavior types will have contrasting caudal morphologies. This study investigates caudal morphology of several New World monkeys representing the large range of ability from totally nonprehensile tails to the dexterous fifth limb of spider monkeys. One large-bodied, nonprehensile-tailed Old World monkey is included to offset the correlation between size and degree of prehensility in New World monkeys. These monkeys vary both within and between species as to the number of caudal vertebrae and the length of individual vertebrae. Despite this variation, the length of caudal vertebrae within a given tail decreases at a constant rate across species. The width of the vertebrae at two points, midbone and the proximal end, separates the monkeys with prehensile tails from those with nonprehensile tails. The middle of the vertebrae is wider and more robust in prehensile-tailed forms. This is associated with stronger bones in tails subject to greater stress. THe proximal width of each bone is also greater in the prehensile-tailed monkeys. This measure reflects the lateral development of the proximal transverse process. This provides a larger lever arm for M. caudalis lateralis, implying greater rotational ability.

Animals↗
PubMed1988

Directional asymmetry in the forelimb of Macaca mulatta.

Asymmetry was investigated in the forelimbs of 150 rhesus monkey (Macaca mulatta) skeletons using measurements of right and left humerii, radii, ulnae, second metacarpals, and femora. Seven of the ten forelimb dimensions were larger on the right than on the left side. Paired t-tests revealed that the mean of the right side was significantly larger than that for the left for two measurements of the ulna and two of the humerus. No measurement was significantly larger on the left than on the right side. These results indicate a small but significant asymmetry in the forelimb bones of rhesus monkeys and, as is the case for humans, the direction of asymmetry favors the right side. Our findings are consistent with an interpretation of hypertrophy of certain muscles and opens the question of whether rhesus monkeys preferentially use their right forelimbs for manipulative tasks that require manual dexterity, as is the case for humans. These forelimb skeletal asymmetries are discussed in light of the recent literature on cortical asymmetry and handedness in nonhuman primates.

Animals↗
PubMed1989

New hominid fossils from the Swartkrans formation (1979-1986 excavations): postcranial specimens.

New postcranial fossils of Paranthropus robustus and Homo cf. erectus were recovered from Swartkrans from 1979 through 1986. These fossils are from Members 1, 2, and 3. The new fossils are described here along with their morphological affinities. Fossils that are assigned to Paranthropus indicate that the South African "robust" australopithecines engaged in tool behavior and were essentially terrestrial bipeds at around 1.8 Myr BP. The manual dexterity and bipedal locomotion of Paranthropus may have equaled that of Homo habilis in East Africa at approximately the same time.

Africa, Southern↗
PubMed1994

Locomotion in captive Leontopithecus and Callimico: a multimedia study.

Video studies, gait analysis, footprint tracks, and observational scan sampling show that, in comparably furnished enclosures, Leontopithecus rosalia and Callimico goeldii are superficially similar in their use of predefined locomotor patterns but differ profoundly in many underlying details which reflect differences in postcranial morphology. Each uses pronograde arboreal quadrupedal walking, quadrupedal bounding, and vertical climbing with comparable frequency, and both shift to bounding while moving quadrupedally at high speeds. In walking, both species use a diagonal sequence gait. However, in Callimico the distance per bout traveled while walking or running is shorter than in L. rosalia and there is an emphasis on leaping (from a stationary position) and bounding-leaps (saltational extensions of pronograde quadrupedalism), in contrast with the basically quadrupedal style of L. rosalia. This dichotomy is consistent with anatomical specializations, such as forelimb elongation in Leontopithecus and hindlimb elongation in Callimico. In vivo hand- and footprint studies demonstrate grasping halluces in both species while walking. Limb stances in L. rosalia during "transaxial bounding" involve an overstriding hindlimb, a predominance of oblique rather than in-line travel, and unique hand and foot positions. Anatomically, this locomotor style may be associated with reduced dexterity of the elongate hands and a relatively short hallux. The captive locomotor profiles for both species probably reflect biased samples of the locomotor repertoire of their wild counterparts. Nevertheless, these data reflect species-specific integrations of locomotor behavior and morphology, and corroborate expectations of locomotor diversity among callitrichine primates, even those of similar body size. It is suggested, however, that conventional quantitative studies of locomotor profiles may prove inadequate for resolving subtle aspects of locomotor morphology and behavior.

Animals↗
PubMed1991

Correlation of phasic muscle strength and corticomotoneuron conduction time in multiple sclerosis.

Central motor conduction times for the adductor pollicis muscle, the twitch force of that muscle to scalp magnetic motor cortex stimulation, and the maximum force of phasic voluntary contraction of the same muscle were measured in 15 patients with multiple sclerosis. Two tests of manual dexterity of the same hand also were studied: the Purdue pegboard test, and the maximal frequency of a scissors movement of the thumb and index finger. The patients had normal strength or minimal weakness of the intrinsic muscles of the hand on clinical examination. The mean central motor conduction times for the adductor pollicis muscle for the patients were longer than normal, the peak twitch force of the adductor pollicis muscle evoked by cortical stimulation and the maximum force of a phasic voluntary contraction of the adductor pollicis muscle were smaller than normal. There were strong correlations between all these measures. Central motor conduction time in the patients was inversely correlated with voluntary phasic force and the twitch force after cortical stimulation. That is, the longer the central motor conduction time, the weaker the force. Prolonged central motor conduction time is likely to be accompanied by conduction block in corticomotoneuron pathways. The correlation of central motor conduction time with voluntary phasic force and the twitch force most likely reflects the degree of conduction block and temporal dispersion rather than delay in conduction per se. These results indicate that objective assessments of phasic muscle strength may reveal correlations with central motor conduction time that are not evident on conventional clinical examination which assesses tonic muscle contraction strength.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Clinical correlates of [18F]fluorodopa uptake in five grafted parkinsonian patients.

To assess the efficacy of fetal mesencephalic grafts in Parkinson's disease, it is important to know if the grafted cells survive and are functional. Positron emission tomography (PET) and [18F]fluorodopa ([18F]dopa) have been used to demonstrate the survival of the grafted cells, but the relationship of [18F]dopa uptake changes in the grafted striatum to motor function remains unclear. We investigated this question with 16 serial PET scans in 5 severe parkinsonian patients unilaterally grafted in whom we found a significant and progressive increase of the [18F]dopa uptake in the grafted putamen. The number of patients was too small to assess the sensitivity of [18F]dopa PET scans in individual patients. Yet, by analyzing the 16 serial PET scans we found a correlation between the [18F]dopa uptake (Ki) in the grafted putamen and the percentage of daily time spent "on," suggesting that Ki changes have a functional meaning. In addition, the Ki values were correlated with the contralateral finger dexterity to the same extent in both the grafted and nongrafted putamen. These results indicate that [18F]dopa uptake reflects the motor function of the opposite side of the body, similarly in the grafted and ungrafted putamen, at least in terms of these tasks. Finally, extrapolating from these correlations offers the suggestion that clinical optimal results of the graft could be achieved if the graft brings the Ki values in the putamen to about two standard deviations of mean control values.

Brain↗
PubMed1987

Evidence of the validity of the Arthritis Impact Measurement Scales.

The Arthritis Impact Measurement Scales (AIMS) were administered to 120 patients with rheumatoid arthritis. These patients also rated the importance of various aspects of their treatment. Our findings support the validity of the pain, anxiety, depression, dexterity, and physical activity subscales of the AIMS. The household activity subscale, however, may not be appropriate for use with men, and the activities of daily living subscale may be insensitive to mild impairment.

Activities of Daily Living↗
PubMed1987

Assessment of the reliability and validity of the arthritis impact measurement scales for children with juvenile arthritis.

There are few multidimensional measures of functional status in children, and none have been developed for children with juvenile arthritis (JA). This report describes an attempt to apply selected components of the Arthritis Impact Measurement Scales (AIMS), which were developed and validated for adults, to a sample of children with active JA (n = 60) or inactive JA (n = 17). Our results suggest that the Pain scale and the Physical Activity scale are the most reliable measures for children with JA; the correlations of the Pain scale, Physical Activity scale, and Dexterity scale results with the clinical measures of JA diagnostic category and joint count support the convergent validity of these scales for the active JA group; and the AIMS revised Physical Disability dimension and the Pain dimension, used to predict the children's classification in the active or inactive JA group, evidence discriminant validity. Additional studies of children with a wider range of impairments are needed to further assess the usefulness of the AIMS for children with JA.

Arthritis, Juvenile↗
PubMed1986

Simulation in surgical training using freeze dried material.

The acquisition of manual dexterity and surgical skills is usually achieved in the operating theatre under supervision. We describe an efficient way of learning intestinal anastomosis procedures with the use of gamma irradiated, lyophilized porcine or bovine tissues together with a purpose designed holding jig. Preliminary evaluation of this method with untrained subjects showed that they were able to improve their performance. Because the tissues are sterile, health hazards are avoided and no special laboratory facilities are required. This approach has promise as an aid to evaluation as well as training.

Animals↗
PubMed1994

Psychomotor skills of surgical trainees compared with those of different medical specialists.

Forty-eight trainees in surgery, psychiatry, anaesthetics and medicine underwent objective testing of manual dexterity (Mandex test), hand-eye coordination (Gibson spiral maze test) and visuospatial ability (embedded figures task). Surgical trainees performed significantly more quickly on the spiral maze test than psychiatrists (P = 0.03) but made more errors (P = 0.02). Combining male and female subjects across all groups, women were significantly more accurate than men. When men only were compared no psychomotor differences between specialty groups could be demonstrated. There were no differences in visuospatial ability by either sex or specialty. Self-selection on the basis of such skill is therefore unlikely.

Adult↗
PubMed2003

Surgeons and cognitive processes.

BACKGROUND: The surgical mind is geared to make important decisions and perform highly skilled tasks. The aim of this review is to explore the cognitive processes that link these actions. METHODS: The core of this review is derived from a literature search of a computer database (Medline). RESULTS AND CONCLUSION: The surgical image is one of action. However, the effective performance of surgery requires more than mere manual dexterity and it is evident that competent surgeons exhibit the cognitive traits that are held by all experts. The changes that are occurring in surgery indicate a need to place greater emphasis on the cognitive processes that underpin the practice of surgery. It is important that surgeons do not become victims of their own cult image.

Clinical Competence↗
PubMed2004

Laparoscopic skills training and assessment.

BACKGROUND: The introduction of laparoscopic techniques to general surgery was associated with many unnecessary complications, which led to the development of skills laboratories to train novice laparoscopic surgeons. This article reviews the tools currently available for training and assessment in laparoscopic surgery. METHODS: Medline searches were performed to identify articles with combinations of the following key words: laparoscopy, training, curriculum, virtual reality and assessment. Further articles were obtained by manually searching the reference lists of identified papers. RESULTS: Current training involves the use of box trainers with either innate models or animal tissues; it lacks objective assessment of skill acquisition. Virtual reality simulators have the ability to teach laparoscopic psychomotor skills, and objective assessment is now possible using dexterity-based and video analysis systems. CONCLUSION: The tools are now available for the development of a structured, competency-based, laparoscopic surgical training programme.

Clinical Competence↗
PubMed2006

Negative stress-coping strategies among novices in surgery correlate with poor virtual laparoscopic performance.

BACKGROUND: This study explored the impact of habitual stress-coping strategies on the laparoscopic performance of novices in surgery using a virtual reality simulator. METHODS: The SVF78 stress-coping questionnaire was administered to 12 medical students in their final year of medical school (camera holders) and to 12 inexperienced surgical residents (postgraduate years 1-3). The questionnaire included devaluation during stressful situations, distractions from stressful situations, control over stressful reactions and negative coping strategies such as stress avoidance and need for social support. Assessment of laparoscopic dexterity was based on the results of performance on a virtual reality simulator. The variables of time taken to complete the task, errors and economy of motion were analysed, with a higher score indicating poor performance. Pearson and non-parametric Spearman correlations were used to compare the subjects' results on the SVF78 with those on the LapSim. RESULTS: Time taken to complete the task correlated with high values in distractive stress-coping strategies (P = 0.002) and high values in negative stress-coping strategies (P = 0.042). CONCLUSION: Ineffective stress-coping strategies correlate with poor virtual laparoscopic performance. The need for effective intraoperative stress-coping strategies is evident.

Adaptation, Psychological↗
PubMed2005

Triplet-triplet energy transfer controlled by the donor-acceptor distance in rigidly held palladium-containing cofacial bisporphyrins.

Eleven new complexes, including mono-, heterobi-, and homobimetallic cofacial bisporphyrins, (Pd)H2DPS, (M)H2DPX, (M)H2DPB, (PdZn)DPS, (PdZn)DPX, (Pt)2DPX, (M)2DPB (M = Pd, Pt), and (Pt)P (DPS4- = 4,6-bis[5-(2,8,13,17-tetraethyl-3,7,12,18-tetramethylporphyrinyl)]dibenzothiophene tetraanion, DPX(4-) = 4,5-bis[5-(2,8,13,17-tetraethyl-3,7,12,18-tetramethylporphyrinyl)]-9,9-dimethylxanthene tetraanion, DPB4- = 1,8-bis[5-(2,8,13,17-tetraethyl-3,7,12,18-tetramethylporphyrinyl)]biphenylene tetraanion, P2- = 5-phenyl-2,8,13,17-tetraethyl-3,7,12,18-tetramethylporphyrin dianion) have been synthesized and characterized. The photophysical properties of the donor (M)P (M=Pd or Pt, P=porphyrin chromophore) and the acceptor (free base H(2)P or (Zn)P) depend on the C(meso)-C(meso) distance and the presence of a heavy atom such as Pd(II) or Pt(II). The data were compared with those for the known compounds (Pd)2DPS, (Pd)2DPX, H4DPS, H4DPX, H4DPB, (Pd)P, (Zn)P, and H(2)P. The rate constants for triplet-triplet energy transfer (k(ET)) were measured for the heterobimetallic (PdZn) and monometallic [(M)H2] derivatives (M=Pd, Pt). The fluorescence lifetimes (Deltatau(F)) of the acceptors decrease as a result of the heavy-atom effect, and vary as follows: (Pd)H2DPS<<(Pd)H2DPX approximately (Pd)H2DPB. The k(ET) values calculated according to the equation k(ET)=(1/tau(emi)-1/tau(emi) (0)), where tau(emi) (0) is the emission lifetime of the homobimetallic bisporphyrins (no ET occurs), are equal to 0, 247+/-57 and 133+/-52 s(-1) for DPS, DPX, and DPB, respectively, in the (Pd)H(2) series. These measurements allowed the range of distance over which the Dexter mechanism for T(1)-T(1) energy transfer ceases to operate to be determined. This distance is somewhere between 4.3 and 6.3 A, in agreement with our recent findings on singlet-singlet energy transfer. During the course of this study, the X-ray crystal structure for (Pd)H2DPX was obtained; triclinic (P1), a = 11.1016(1), b = 14.9868(2), c = 20.6786(3) A, alpha = 102.091(1), beta = 100.587(1), gamma = 101.817(1) degrees , V = 3199.19(7) A(3), Z = 2.

Crystallography, X-Ray↗
PubMed2004

'Chemobrain' in breast carcinoma?: a prologue.

BACKGROUND: Chemotherapy-induced cognitive dysfunction in patients with breast carcinoma has been described previously. However, those studies only assessed patients' postchemotherapy cognitive functioning and were not able to determine the relation between cognitive function and other treatments, such as surgery and radiotherapy, that often precede systemic chemotherapy. METHODS: Eighty-four women with breast carcinoma underwent a comprehensive neuropsychologic evaluation before receiving adjuvant therapy for nonmetastatic primary breast carcinoma. RESULTS: Before the start of systemic therapy, 35% of women in the current cohort exhibited cognitive impairment. Verbal learning (18%) and memory function (25%) were impaired significantly more frequently relative to normative expectations. Although the impairments were not significant in the women who were examined, nonverbal memory (17%), psychomotor processing speed and attention (13%), confrontational naming (13%), visuoconstruction (13%), and upper-extremity fine motor dexterity (12%) were impaired more frequently than was expected. Affective distress was related significantly to cognitive impairment (Pearson chi-square = 9.90; P = 0.002). Given the conservative statistical approach employed, extent of surgery, hormone replacement therapy history, and current menopausal status failed to achieve statistical significance, but these variables did exhibit provocative trends with respect to cognitive impairment. CONCLUSIONS: Cognitive impairment frequently is observed before the administration of systemic chemotherapy. Thus, investigations purporting to measure chemotherapy-induced cognitive dysfunction must employ study designs that incorporate prechemotherapy baseline assessments to accurately detect changes in cognitive function that are attributable to chemotherapy.

Adult↗
PubMed2001

Thalamo-cortical connections of areas 3a and M1 in marmoset monkeys.

The present investigation is part of a broader effort to examine cortical areas that contribute to manual dexterity, reaching, and grasping. In this study we examine the thalamic connections of electrophysiologically defined regions in area 3a and architectonically defined primary motor cortex (M1). Our studies demonstrate that area 3a receives input from nuclei associated with the somatosensory system: the superior, inferior, and lateral divisions of the ventral posterior complex (VPs, VPi, and VPl, respectively). Surprisingly, area 3a receives the majority of its input from thalamic nuclei associated with the motor system, posterior division of the ventral lateral nucleus of the thalamus (VL), the mediodorsal nucleus (MD), and intralaminar nuclei including the central lateral nucleus (CL) and the centre median nucleus (CM). In addition, sparse but consistent projections to area 3a are from the anterior pulvinar (Pla). Projections from the thalamus to the cortex immediately rostral to area 3a, in the architectonically defined M1, are predominantly from VL, VA, CL, and MD. There is a conspicuous absence of inputs from the nuclei associated with processing somatic inputs (VP complex). Our results indicate that area 3a is much like a motor area, in part because of its substantial connections with motor nuclei of the thalamus and motor areas of the neocortex (Huffman et al. [2000] Soc. Neurosci. Abstr. 25:1116). The indirect input from the cerebellum and basal ganglia via the ventral lateral nucleus of the thalamus supports its role in proprioception. Furthermore, the presence of input from somatosensory thalamic nuclei suggests that it plays an important role in somatosensory and motor integration.

Action Potentials↗