Relationship between cognitive and motor performance in physically well-recovered men with traumatic brain injury

OBJECTIVE

To explore the relationship between cognitive and motor performance in physically well-recovered men with traumatic brain injury.

DESIGN

Cross-sectional explorative study in a national neurorehabilitation centre.

SUBJECTS

Men with post-acute traumatic brain injury (n = 34; aged 19-55 years) who had recovered well physically.

METHODS

Cognitive performance (attention, information processing, cognitive flexibility, motor regulation, praxis of the upper limbs) and motor performance (postural balance, agility, rhythm-co-ordination) were assessed. Partial rank correlation coefficients and analyses of covariance were used to assess the associations between these tests.

RESULTS

Associations were found between the time taken in both Trail Making tests and performance time in the agility test (r = 0.57). The score on the Digit Symbol test correlated with time in the agility test (r = -0.52). Patients with normal performance in verbal fluency performed the tests of dynamic balance and agility 26% more quickly than those with abnormal performance. Moreover, patients with normal performance in the reproduction of rhythmic structures were 20% faster in the dynamic balance test. Motor functions of the hands associated with all the motor-performance test results.

CONCLUSION

Measures of information processing, attention and executive functioning may be associated with motor performance. Apart from the theoretical relevance, the finding of an association between cognitive and motor performance may have clinical relevance with regard to rehabilitation.

Quantifications of dendrochronological information from contrasting microdensitometric measuring circumstances of experimental wood samples

We analyzed how the pretreatment method of Scots pine (Pinus sylvestris L.) wood specimens together with X-ray methodology applied for density analyses affect resulting tree-ring data and derived proxy-based climate information. We also evaluated whether these results from two contrasting laboratory circumstances could be homogenized by applying dendroclimatic statistical methods. For this study, we measured a pair of X-ray based microdensitometry datasets using double samples of subfossil and recent wood specimens. Dendrochronological information of earlywood and latewood series was examined to determine for alterations in the resulting data. We found that the level of overall density, its trend over cambial ages and the growth amplitude altered due to the sample pretreatment/density measuring exercise, which means that comparisons of heterogeneous datasets should be, in general, regarded cautiously. Dendrochronological standardization did, however, even out several potentially biasing influences from the differing overall densities and their trends. The two latewood (maximum) density chronologies yielded paleoclimatic reconstructions which both calibrated and verified satisfactorily with the instrumental warm-season (March-September) mean temperatures. The transfer functions were found to further equalize the differences between the two proxy records. We recommend (if no strictly homogenous data are available) reconciling similar data assemblages through transfer functions with multiple independent variables.

A Framework to Analyze Knowledge Work in Distributed Teams

This article presents a framework to analyze knowledge work in the changing context of new ways of working. Knowledge work increasingly takes place as collaboration from different and changing workplaces due to mobility, multilocational, and geographical distribution of participants. We define the framework based on five key factors that pose challenges to the performance and productivity of knowledge work performed in distributed teams. The framework extends and integrates traditional performance models of task, team structure, and work process, with context factors like workplace, organization policy, and information and communication technology (ICT) infrastructure. The framework is applied in a qualitative comparative cross-case analysis to eight globally distributed teams in two Fortune 100 high-tech companies. We conclude with a series of specific challenges for each factor when studying distributed knowledge work. It is shown that due to changing contexts knowledge workers, teams, and organizations need to constantly adapt, readjust, and realign according to the five factors.

Self-Determined Adoption of an ICT System in a Work Organization

This descriptive single case study examines the process and implications of the self-determined adoption of an internet-based meeting system in a global company. Self-determination theory and structuration theory are used as theoretical lenses to understand the adoption and use of an ICT system. The data were collected using qualitative semi-structured interviews with eleven system users and analyzed using a content analysis approach. The research shows that the self-determined adoption of ICT systems has benefits like user motivation and satisfaction. Problems in such adoption relate to users’ experiencing uncertainty regarding the organizational legitimization of the system and support for its use. Employees and organizations are likely to benefit from self-determined adoption because it promotes employees’ motivation and initiative-taking. However, a shared understanding of self-determination and organizational support for it are required.

Physiotherapy for female stress urinary incontinence: individual therapy at the outpatient clinic versus home-based pelvic floor training: a 5-year follow-up study

AIMS

To compare the long-term effects of individual physiotherapy at an outpatient clinic, including electrical stimulation (ES), active pelvic floor muscle exercises (PFMEs), and training with a vaginal ball (VB), with home-based active PFMEs and training with a VB, in cases of female stress urinary incontinence (SUI).

MATERIALS AND METHOD

Thirty-three women with SUI (outpatient clinic group [Group I, n = 16] and home group [Group II, n = 17]) participated in the 5-year follow-up study. Both groups had an active PFME program and they used a VB during daily activities for intensive pelvic floor muscle (PFM) training. Group I was also treated at the outpatient clinic with maximal interferential ES, using frequencies varying from 10 to 50 Hz, and individually instructed exercises with biofeedback were carried out at the same time, once a week, an average of nine times in the first year. After baseline examinations, both groups visited the outpatient clinic at 4 months, 12 months, and at 5 years.

RESULTS

At 12 months, there were no statistically significant differences between the study groups in any of the outcome variables, but within the groups both the subjective and objective results were significantly better in comparison with the initial values. After 12 months, two (3%) patients in Group I continued physiotherapy and seven (41%) patients in Group II needed physiotherapy because of an unsatisfactory outcome. At 5 years, according to the urinary incontinence severity score (UISS) questionnaire, subjective discomfort had decreased in both groups (P < 0.01) and 21 of the 33 women (64%) perceived a subjective cure or improvement in their condition. The mean objective urine leakage verified by the pad test decreased from 23.0 to 1.0 g in Group I and from 13.0 to 1.0 g in Group II (P < 0.001 for both groups). The strength of PFMs tested in a standing position increased by 26% in Group I and by 19% in Group II (P values 0.001 and 0.084, respectively), and in a lying position by 28% in Group I and by 32% in Group II (P values 0.001 and 0.008, respectively).

CONCLUSIONS

Home-based PFMEs and training with a VB proved to be equally effective as once-a-week supervised therapy, and the 5-year follow-up results demonstrated a successful response in the treatment of female SUI.

Residential indoor, outdoor, and workplace concentrations of carbonyl compounds: relationships with personal exposure concentrations and correlation with sources

Personal 48-hr exposures of 15 randomly selected participants as well as microenvironment concentrations in each participant's residence and workplace were measured for 16 carbonyl compounds during summer-fall 1997 as a part of the Air Pollution Exposure Distributions within Adult Urban Populations in Europe (EXPOLIS) study in Helsinki, Finland. When formaldehyde and acetaldehyde were excluded, geometric mean ambient air concentrations outside each participant's residence were less than 1 ppb for all target compounds. Geometric mean residential indoor concentrations of carbonyls were systematically higher than geometric mean personal exposures and indoor workplace concentrations. Additionally, residential indoor/outdoor ratios indicated substantial indoor sources for most target compounds. Carbonyls in residential indoor air correlated significantly, suggesting similar mechanisms of entry into indoor environments. Overall, this study demonstrated the important role of non-traffic-related emissions in the personal exposures of participants in Helsinki and that comprehensive apportionment of population risk to air toxics should include exposure concentrations derived from product emissions and chemical formation in indoor air.

Twinfilin is required for actin-dependent developmental processes in Drosophila

The actin cytoskeleton is essential for cellular remodeling and many developmental and morphological processes. Twinfilin is a ubiquitous actin monomer-binding protein whose biological function has remained unclear. We discovered and cloned the Drosophila twinfilin homologue, and show that this protein is ubiquitously expressed in different tissues and developmental stages. A mutation in the twf gene leads to a number of developmental defects, including aberrant bristle morphology. This results from uncontrolled polymerization of actin filaments and misorientation of actin bundles in developing bristles. In wild-type bristles, twinfilin localizes diffusively to cytoplasm and to the ends of actin bundles, and may therefore be involved in localization of actin monomers in cells. We also show that twinfilin and the ADF/cofilin encoding gene twinstar interact genetically in bristle morphogenesis. These results demonstrate that the accurate regulation of size and dynamics of the actin monomer pool by twinfilin is essential for a number of actin-dependent developmental processes in multicellular eukaryotes.

Comparison of the effect on acne with a combiphasic desogestrel-containing oral contraceptive and a preparation containing cyproterone acetate

OBJECTIVE

To investigate the effect of a combiphasic oral contraceptive containing ethinylestradiol and desogestrel (combiphasic EE/DSG) on acne, compared with a preparation containing ethinylestradiol and cyproterone acetate (EE35/CPA).

METHODS

An open, randomized, group-comparative, multicenter study was carried out, with 172 women randomized to treatment with either combiphasic EE/DSG (25 microg desogestrel and 40 microg ethinylestradiol for 7 days followed by 125 microg desogestrel and 30 microg ethinylestradiol for 15 days) or EE35/CPA (2.0 mg cyproterone acetate and 35 microg ethinylestradiol for 21 days). Assessments were performed at pretreatment and after cycles 3 and 6.

RESULTS

The number of comedones, papules, pustules and nodules significantly decreased in both groups over the 6-month study. Compared with pretreatment (= 100%), the relative numbers of comedones, papules, pustules and nodules at cycle 6 significantly decreased to 37%, 38%, 19% and 12.5% in the combiphasic EE/DSG group and to 24%, 36%, 17% and 1% in the EE35/CPA group, respectively. All reductions were statistically significant (p < or = 0.003) at both cycles 3 and 6, except for nodules at cycle 6 with combiphasic EE/DSG, which probably resulted from differences between the treatment groups at baseline. There were no statistically significant differences between the two treatments. In both groups, the majority of women with severe acne shifted to a less severe acne category.

CONCLUSIONS

Combiphasic EE/DSG progressively reduced the number and severity of acne lesions during the six cycles of treatment. The reduction in acne with the combiphasic oral contraceptive was comparable to a preparation containing the antiandrogen cyproterone acetate.

Personal exposure levels and microenvironmental concentrations of formaldehyde and acetaldehyde in the Helsinki metropolitan area, Finland

Personal 48-hr exposures to formaldehyde and acetaldehyde of 15 randomly selected participants were measured during the summer/autumn of 1997 using Sep-Pak DNPH-Silica cartridges as a part of the EXPOLIS study in Helsinki, Finland. In addition to personal exposures, simultaneous measurements of microenvironmental concentrations were conducted at each participant's residence (indoor and outdoor) and workplace. Mean personal exposure levels were 21.4 ppb for formaldehyde and 7.9 ppb for acetaldehyde. Personal exposures were systematically lower than indoor residential concentrations for both compounds, and ambient air concentrations were lower than both indoor residential concentrations and personal exposure levels. Mean workplace concentrations of both compounds were lower than mean indoor residential concentrations. Correlation between personal exposures and indoor residential concentrations was statistically significant for both compounds. This indicated that indoor residential concentrations of formaldehyde and acetaldehyde are a better estimate of personal exposures than are concentrations in ambient air. In addition, a time-weighted exposure model did not improve the estimation of personal exposures above that obtained using indoor residential concentrations as a surrogate for personal exposures. Correlation between formaldehyde and acetaldehyde was statistically significant in outdoor microenvironments, suggesting that both compounds have similar sources and sinks in ambient urban air.

Mouse A6/twinfilin is an actin monomer-binding protein that localizes to the regions of rapid actin dynamics

In our database searches, we have identified mammalian homologues of yeast actin-binding protein, twinfilin. Previous studies suggested that these mammalian proteins were tyrosine kinases, and therefore they were named A6 protein tyrosine kinase. In contrast to these earlier studies, we did not find any tyrosine kinase activity in our recombinant protein. However, biochemical analysis showed that mouse A6/twinfilin forms a complex with actin monomer and prevents actin filament assembly in vitro. A6/twinfilin mRNA is expressed in most adult tissues but not in skeletal muscle and spleen. In mouse cells, A6/twinfilin protein is concentrated to the areas at the cell cortex which overlap with G-actin-rich actin structures. A6/twinfilin also colocalizes with the activated forms of small GTPases Rac1 and Cdc42 to membrane ruffles and to cell-cell contacts, respectively. Furthermore, expression of the activated Rac1(V12) in NIH 3T3 cells leads to an increased A6/twinfilin localization to nucleus and cell cortex, whereas a dominant negative form of Rac1(V12,N17) induces A6/twinfilin localization to cytoplasm. Taken together, these studies show that mouse A6/twinfilin is an actin monomer-binding protein whose localization to cortical G-actin-rich structures may be regulated by the small GTPase Rac1.

Urban commuter exposure to particle matter and carbon monoxide inside an automobile

In-vehicle exposures to different sizes of particles and carbon monoxide (CO) were determined while driving along a standardized route under a variety of traffic conditions in Kuopio, Finland during the 12-month period from January to December 1995. Arithmetic means of in-vehicle exposures during the morning rush hours were 5.7 parts per million (ppm) (geometric mean, GM = 3.1 ppm, geometric standard deviation, GSD = 1.7) for CO, 107 #/cm3 (GM = 75 #/cm3, GSD = 1.9) for fine particles (optical equivalent particle size range 0.3-1 micron) and 0.9 #/cm3 (GM = 0.6 #/cm3, GSD = 2.1) for coarse particles (optical equivalent particle size range 1-10 microns). Fine particles and CO behaved similarly in different weather and traffic conditions, while the behavior of coarse particles was usually different, and often opposite. The driving conditions that affected the passengers' exposures to CO and fine particles were the time of day (morning vs. afternoon) and average speed (decreasing). The meteorological parameters that affected the passengers' exposures to CO and fine particles were wind speed (decreasing) and relative humidity (increasing). Wind speed, relative humidity and driving speed all had opposite effects on the exposure levels to fine vs. coarse particles. Added exposures (due to commuting on top of the background levels) to CO and fine particles were considerably higher in the morning vs. the afternoon runs and also higher in the slower vs. the faster runs.

Determination of urinary 2-mercaptobenzothiazole (2-MBT), the main metabolite of 2-(thiocyanomethylthio)benzothiazole (TCMTB) in humans and rats

A method for biological monitoring of urinary 2-(thiocyanomethylthio)benzothiazole (TCMTB), a wood preservative and an industrial chemical, was developed. Three different doses of TCMTB in olive oil were given to male rats by gavage for 3 weeks. Urine was collected daily and the metabolites were analysed as thioethers by derivatization with pentafluorobenzyl-bromide by gas chromatography-mass spectrometry. The parent chemical was not detected in urine samples, but two metabolites of TCMTB were identified. 2-Mercaptobenzothiazole (2-MBT) was the main metabolite, and its excretion varied according to the dose. The second metabolite was 2-(mercaptomethylthio)benzothiazole. The amount of 2-MBT excreted in rat urine was 66 +/- 12% (SD), 51 +/- 20% and 44 +/- 9% for TCMTB doses of 15, 75 and 150 mg/kg, respectively. Two doses, 75 and 150 mg/kg, caused diuresis in rats during the 1 week of dosing. During the 3-week TCMTB treatment, rat liver microsomal CYP enzyme profile was not significantly changed. Urine samples of sawmill workers exposed to TCMTB were collected after their work shifts for exposure assessment. TCMTB could not be detected in the urine samples of exposed workers. Most concentrations of 2-MBT were below the limit of the detection, 0.12 mumol/l, the concentrations were 0.12-0.15 mumol/l only in few cases. The determination of 2-MBT in urine, when a sample is taken immediately after a work shift, is a suitable indicator of workers' exposure to TCMTB.

Low density lipoprotein degradation by secretory granules of rat mast cells. Sequential degradation of apolipoprotein B by granule chymase and carboxypeptidase A

The secretory granules of rat serosal mast cells are able efficiently to degrade the apolipoprotein B component of low density lipoproteins (LDL) Kokkonen, J. O., and Kovanen, P. T. (1985) J. Biol. Chem. 260, 14756-14763). The granules are known to contain two neutral proteases with complementary specificities: a chymotrypsin-like endopeptidase called chymase, and an exopeptidase, the granule carboxypeptidase A. The role of this enzyme pair in the proteolytic degradation of LDL was studied with the aid of specific enzyme inhibitors. Incubation of LDL with intact granules (both enzymes active) led to the formation of numerous low molecular weight peptides and the liberation of free amino acids, most of which (95%) were aromatic (Phe, Tyr, Trp) or branched-chain aliphatic (Leu, Ile, Val). Selective inhibition of granule carboxypeptidase A (leaving chymase active) blocked the liberation of free amino acids, but left the formation of peptides uninhibited. On the other hand, selective inhibition of granule chymase (leaving carboxypeptidase A active) totally abolished the proteolytic degradation of LDL. The results are consistent with a model according to which the proteolytic degradation of LDL by mast cell granules results from coordinated action of the two granule-bound enzymes, whereby the chymase first cleaves peptides from the apolipoprotein B of LDL, and thereafter the carboxypeptidase A cleaves amino acids from the peptides formed.

Comparison of activated charcoal and ipecac syrup in prevention of drug absorption

The efficacy of activated charcoal and ipecac syrup in the prevention of drug absorption was studied in 6 healthy adult volunteers, using a randomized, cross-over design. Paracetamol 1000 mg, tetracycline 500 mg and aminophylline 350 mg were ingested on an empty stomach with 100 ml water. Then, after 5 or 30 min, the subjects ingested, either activated charcoal suspension (50 g charcoal), syrup of ipecac, or, only after 5 min, water 300 ml. Activated charcoal, given either after 5 or 30 min, significantly (p less than 0.01 or less 0.05) reduced the absorption of these 3 drugs measured, for example as AUC0-24 h. Syrup of ipecac caused emesis on each occasion, with a mean delay of 15 min. When ipecac was given 5 min after the drugs, its effect on absorption was significant, but when it was given after 30 min only the absorption of tetracycline was reduced. Activated charcoal was significantly (p less than 0.05) more effective than ipecac in reducing drug absorption when given at the same time points. In cases of acute intoxication, depending on the quality and quantity of the drugs ingested, the relative efficacy of charcoal and ipecac may be somewhat different from that observed in the present study. Despite its emetic action, however, ipecac syrup is not very effective in preventing drug absorption and, in general, activated charcoal should also be given after induced emesis or gastric lavage.

Paradoxical heat sensations during moderate cooling of the skin

Paradoxical heat sensations during cooling of the skin were examined in two experiments. In Expt. I the number of occurrences of sensation was studied in 19 naive test subjects (Ss) when cooling from thermal indifference both without and with preceding heating. Without preceding heating 13 Ss reported sensations of paradoxical heat (9.8% of all stimulations). Preheating markedly facilitated the occurrence of the sensations (35% of all stimulations). In Expt. II the effects of cooling velocity (velocities 0.4, 0.7 and 2.0 degrees C/s) and the type of skin area stimulated (hairy or glabrous skin of the hand) on the thresholds of paradoxical sensations were studied in 4 Ss without and with preheating. Cooling velocity, type of skin area and preheating had significant effects on the sensation thresholds, the thresholds being the higher (i.e. the sensation appearing at lower stimulation temperatures) the higher the cooling velocity, if the stimuli were applied to the glabrous skin, or if no preheating was used. The results confirm the existence of paradoxical heat sensations during cooling of the skin and suggest that the sensation is mediated by polymodal units supplied by C-fibers.

Characterization of two synaptosomal peptides in calf brain

Two low-molecular weight peptides occurring in calf brain nerve terminals and their subcellular vesicles were purified by ion-exchange and thin-layer chromatography, adsorption chromatography on copper-Sephadex and gel filtration. Their amino acid composition and sequence were determined using the dansyl chloride method and carboxypeptidase and aminopeptidase. The tentative sequences NH2-alanyl-glycyl-glutamyl-phosphoserine-COOH and N-acetylaspartyl-glutamyl-taurine-SO3 were obtained. Release of both peptides from synaptic vesicles was caused by depolarizing concentrations of K+ and Ca2+ and also by electrical stimulation, but no release from the synaptosomes could be observed. Vesicular origin of the peptides was shown by gel filtration.