Functional MRI and motor behavioral changes obtained with constraint-induced movement therapy in chronic stroke.

BACKGROUND: The clinical benefits of intensive stroke rehabilitation vary individually. We used multimodal functional imaging to assess the relationship of clinical gain and imaging changes in patients with chronic stroke whose voluntary motor control improved after constraint-induced movement therapy (CIMT). METHODS: Eleven patients (37.6 ± 36.8 months from stroke) were studied by functional MRI (fMRI), transcranial magnetic stimulation (TMS), and behavioral assessment of hand motor control (Wolf Motor Function Test) before and after 2 weeks of CIMT. Individual and group-level changes in imaging and behavioral parameters were investigated. RESULTS: Increase in fMRI activation in the sensorimotor areas was greater amongst those subjects who had poor hand motor behavior before therapy and/or whose motor behavior improved notably because of therapy than amongst subjects with relatively good motor behavior already before therapy. The magnitude of CIMT-induced changes in task-related fMRI activation differed between lesioned and non-lesioned hemispheres, and the fMRI laterality index was different for paretic and non-paretic hand tasks. The corticospinal conduction time in TMS was significantly decreased after CIM therapy. CONCLUSIONS: Alterations in sensorimotor cortical activations (fMRI) and corticospinal conductivity (TMS) were observed after intensive rehabilitation in patients with chronic stroke. Activation and functional changes in fMRI and TMS correlated significantly with the degree of clinical improvement in hand motor behavior. The present data advance the understanding of the functional underpinnings of motor recovery, which may be obtained even years after the stroke.

Hemispatial neglect reflected on visual memory.

PURPOSE: Recent studies of hemispatial neglect have revealed both lateralized and nonlateralized attention mechanisms contributing to the syndrome. In addition, neglect patients show impaired spatial working memory and diminished working memory capacity. The aim of this study was to investigate, how neglect would be reflected in their performances in commonly used clinical visual memory tests. METHODS: Twelve patients with right hemisphere lesions and left neglect and twelve matched controls were assessed with the Behavioural Inattention Test, the visual reproduction of the WMS-R, the object memory test, the Rey figure test and the list learning test. Visuo-spatial span was explored with the Corsi block test. RESULTS: The severity of neglect was significantly associated with the naming of objects from the left side, with the copying of the Rey figure and with the immediate visual reproduction of the WMS-R. In comparison to the matched controls, the patients named and copied fewer items from both sides and showed impaired immediate and delayed recall of visual material, more so from the left side. After recovery, patients were still impaired in their visual search, whereas their immediate reproduction of visual material was no longer significantly different from the control subjects. The deficit in delayed recall of visual material persisted and was lateralized to the left side of the recollected memories. The role of hemianopia was analyzed. CONCLUSIONS: Patients with neglect exhibited spatial working memory bias and diminished nonlateralized attention capacity in encoding and immediate recall. The deficit in delayed recall was lateralized to the left side of memorized material.

Comparison of the Behavioural Inattention Test and the Catherine Bergego Scale in assessment of hemispatial neglect.

The objective of the study was to correlate visual and behavioural assessments of hemispatial neglect caused by cerebrovascular accident. We assessed 17 consecutive right-hemisphere stroke patients with hemispatial neglect: the Catherine Bergego Scale (CBS) was used to evaluate neglect in spontaneous behaviour and the conventional subtests of the Behavioural Inattention Test (BIT C) were used to assess visual neglect. The proportional severity of both visual and behavioural neglect was calculated in each individual patient. Dissociations were found between mild neglect in visual screening tasks and moderate or severe neglect in behaviour, although in most patients, neglect was equally evident in both tests. Only the line bisection subtest from the BIT correlated significantly with the CBS, yet both tests showed good internal consistency. The line bisection test and several items of the CBS were especially sensitive in detecting the combination of visual field deficit and hemispatial neglect. In conclusion, we propose that visual fields should always be assessed in patients with neglect because neglect may be exacerbated by a visual field deficit and this can cause prolonged functional disability in everyday life situations. Specific rehabilitation methods might also be needed in neglect with or without hemianopia.

Rehabilitation of hemispatial neglect: A randomized study using either arm activation or visual scanning training.

PURPOSE: Hemispatial neglect, a failure to orient to the contralateral side of the lesion, is a disabling disorder after stroke. Previously arm activation combined with visual training or visual scanning training were found effective in rehabilitation of hemispatial neglect. The aim of this study was to determine whether left arm activation alone could be sufficient to produce a long lasting amelioration of neglect comparable to the effect obtained with traditional visual scanning training. METHODS: Twelve neglect patients less than six months from stroke were randomized either into 20-30 hours of left arm activation training or 10 hours of traditional visual scanning training as a part of a comprehensive rehabilitation program. All patients received 48~hours of therapy during the 3-week rehabilitation. RESULTS: Visual neglect of the arm activation group recovered significantly in the conventional subtests of the Behavioural Inattention Test both post-rehabilitation and at 6-months follow-up. The improvement of the visual scanning training group was almost significant at the end of the rehabilitation and significant by the follow-up. The behavioural neglect observed in the Catherine Bergego Scale was alleviated nearly significantly at the post-rehabilitation in both groups. The effect was maintained in the arm activation group at 6-months. CONCLUSION: The arm activation training appears beneficial even without supplementary visual neglect rehabilitation, although the traditional visual scanning training may have further effects in cognition.

Cutaneous electrical stimulation may enhance sensorimotor recovery in chronic stroke.

OBJECTIVE: To investigate whether cutaneous electrical stimulation has a role in the enhancement of sensorimotor function in chronic stroke. SUBJECTS AND SETTING: Fifty-nine patients with chronic stroke received cutaneous stimulation during their three-week-long inpatient rehabilitation. Thirty-two received active treatment in the paretic hand and eight received no-current placebo treatment in the paretic hand. Nineteen patients received active stimulation of the paretic foot. None received stimulation in both upper and lower limbs. INTERVENTION: Cutaneous stimulation was delivered twice daily via a special glove/sock electrode. MAIN OUTCOME MEASURES: Modified Motor Assessment Scale, 10-metre walking test, paretic limb function, limb skin sensation and somatosensory evoked potentials (SEP) were performed before and after the treatment. RESULTS: Modified Motor Assessment Scale (p < 0.001), 10-metre walking test (p < 0.05), paretic hand function (p < 0.01), upper limb skin sensation (p < 0.01) and SEP normality classification of paretic upper limb (p < 0.01) and paretic lower limb (p < 0.5) improved significantly in the treatment group (n = 51) after three weeks of stimulation. When active hand treatment and placebo hand treatment were compared, a significant improvement in the sensory and motor function was observed only in the actively treated group. CONCLUSIONS: Cutaneous stimulation had positive effects in the motor performance, limb sensation and the configuration of SEP of the paretic limb in chronic stroke patients.

Human melanoma cell line UV responses show independency of p53 function.

UV radiation-induced mutation of the p53 gene is suggested as a causative event in skin cancer, including melanoma. We have analyzed here p53 mutations in melanoma cell lines and studied its stabilization, DNA-binding activity, and target gene activation by UVC. p53 was mutated in three of seven melanoma cell lines. However, high levels of p53 were detected in all cell lines, including melanoma cells with wild-type p53, with the exception of one line with a truncated form. Upon UV induction, p53 accumulated in lines with wild-type p53, and p53 target genes p21Cip1/Waf1, GADD45, and mdm2 were induced, but the induction of p21Cip1/Waf1 was significantly delayed as compared with the increase in p53 DNA-binding activity. However, despite p53 target gene induction, p53 DNA-binding activity was absent in one melanoma line with wild-type p53, and p53 target genes were induced also in cells with mutant p53. In response to UV, DNA replication ceased in all cell lines, and apoptosis ensued in four lines independently of p53 but correlated with high induction of GADD45. The results suggest that in melanoma, several p53 regulatory steps are dislodged; its basal expression is high, its activation in response to UV damage is diminished, and the regulation of its target genes p21Cip1/Waf1 and GADD45 are dissociated from p53 regulation.

U.V.C.-induction of p53 activation and accumulation is dependent on cell cycle and pathways involving protein synthesis and phosphorylation.

Transcriptional activation and stabilization of p53 is a major response of mammalian cells to U.V.-light induced genetic damages, and possibly responsible for cell damage control. We have studied here by gel mobility shift and immunoblotting assays the activation and accumulation of p53 by U.V.C. and its dependency on cell cycle, protein synthesis and protein phosphorylation. In G0/G1 synchronized cells U.V.C.-induced p53 DNA-binding activity, but not its accumulation, whereas both events took place in G1/S and S-phase cells. The kinetics of p53 activation by U.V.C. were slow requiring at least 1 h and slowly increasing thereafter with full activation observed at 6 h. Treatment of cells with cycloheximide (CHX) prevented the activation of p53 in all phases of the cell cycle and its accumulation in G1/S and S. However, removing CHX-block allowed full activation and accumulation of p53 with fast kinetics even if 4 h had lapsed since the initial U.V.C. insult. This suggests that the protein synthesis-dependent signal initiating p53 activation by U.V.C. remains continuous in the cells. The requirement of protein phosphorylation as mediator of p53 activation by U.V.C. was studied by using chemical protein kinase inhibitors. Of the tested inhibitors, only staurosporine, a known inhibitor of protein kinase C (PKC) and various other kinases, inhibited both p53 activation and accumulation, whereas specific PKC inhibitors, tyrosine kinase inhibitors and a serine/threonine kinase inhibitor did not. PKC-mediation of the p53 U.V.-response was further ruled out by the reactivity of the activated p53 to C-terminal antibody PAb 421. Kinetic studies showed that staurosporine-mediated inhibition of p53 function is an early event in cell damage response. Thus dual, kinetically different events, de novo protein synthesis and staurosporine-inhibited protein phosphorylation are required for p53 activation and accumulation in all phases of the cell cycle. Notably, in the absence of U.V.-induced accumulation in G0/G1 cells, p53 activation is still subject to inhibition of protein synthesis.

p53 transactivation and protein accumulation are independently regulated by UV light in different phases of the cell cycle.

DNA damage-induced activation of the p53 tumor suppressor gene is suggested to be central in the cellular damage response pathway. In this study, we analyzed the responses of p53 to UVC radiation in synchronized mouse fibroblasts in terms of p53 accumulation, transcriptional activation, and sequence-specific DNA-binding activity. UVC was found to induce accumulation of p53 cell cycle dependently in G1/S- and S-phase cells but not in G0 or G1 cells. In contrast, p53 transcriptional activity and its target genes, p21 and GADD45, were stimulated by UVC in G0 and G1 cells in the absence of detectable p53 protein. The accumulation of p53 and increased p21 and GADD45 expression were replication dependent in S-phase cells. Interestingly, sequence-specific p53 DNA-binding activity was stimulated also replication independently in S phase, though the effect was not conveyed to stimulation of p53 target genes, suggesting that additional events are required for p53-stimulated gene expression. The results show that opposed to the cell cycle dependence of p53 accumulation, the UVC-mediated transactivation by p53 is independent of the cell cycle phase and protein stabilization.

Cell cycle dependent effects of u.v.-radiation on p53 expression and retinoblastoma protein phosphorylation.

Control of fate of cells encountered with DNA damaging agents is pivotal for normal cellular homeostasis. DNA damage leads in many cases to growth arrest of the cells ensuring sufficient time for damage repair. Growth arrest can be mediated by p53 tumor suppressor protein and loss of its function leads to inability of the cells to both growth arrest and undergo apoptosis. We show here that followed by genotoxic stress, the retinoblastoma gene product, pRB, is associated with growth arrest of cells in a p53 independent manner. In u.v.-treated human and mouse fibroblasts, pRB is rapidly dephosphorylated. pRB dephosphorylation occurs concomitant with growth arrest of cells including cells with p53 mutations (SW 480 colon carcinoma cells), cells expressing SV40 T antigen and rat-transformed cells (T-24 bladder carcinoma cells) unresponsive in regard to p53 stimulation. Furthermore, flow cytometry analysis of u.v.-radiated synchronized G1 cells indicates that the cells transiently arrest in G1 for 10-12 h with pRB dominating in its underphosphorylated form, whereas p53 accumulation occurs only after the cells have entered into S-phase. In addition, u.v.-radiation of late S- and G2/M-phase cells leads to p53 accumulation and cell cycle arrest. The results indicate that p53 accumulation upon u.v.-radiation occurs during DNA replication and is thus not involved in G1 arrest. We suggest that the events that lead to pRB dephosphorylation upon u.v.-radiation provide the cell an efficient G1 arrest which occurs prior and independently of p53.

Human retinoblastoma gene product prevents c-Ha-ras oncogene mediated cellular transformation of mouse fibroblasts.

Suppression of tumor formation and restoration of normal growth of cells has been an insignia that the retinoblastoma gene (RB1) functions as a tumor suppressor gene. The tumor suppressive functions of RB are suggested to associate with regulation of cell cycle events or gene transcription. We have analysed here the interactions of RB and c-Ha-ras oncogene by gene transfection studies. Mouse fibroblasts stably expressing high levels human wild type (wt) pRB or mutant pRB were transfected with genomic or LTR promoter driven c-Ha-ras(Val-12) expression vectors. We find that expression of normal, but not mutant RB protein in the cells prevents c-Ha-ras oncogene mediated cellular transformation and colony formation in soft agar. Analysis of stable RB and genomic c-Ha-ras cell transfectants for expression of pRB and p21ras by immunoblotting indicates a strong correlation with the presence of high levels of RB protein and inhibition of ras-transformation. Moreover, during culturing the RB and genomic c-Ha-ras expressing clones a progressive transformation of phenotypically normal clones was observed which paralleled loss or decrease of RB expression and concomitant increase in p21ras production. These findings suggest a functional cross-talk between RB protein and p21ras, which balances the cell phenotype between normal and transformed states.

Expression of the human retinoblastoma gene product in mouse fibroblasts: effects on cell proliferation and susceptibility to transformation.

Expression of the human retinoblastoma gene (RB1) in tumor cells defective of the gene in many instances abrogates the growth of the cells. Here we have evaluated the characteristics and tumor-suppressive functions of the human retinoblastoma gene product in mouse fibroblasts. Human full-length wild-type or mutant RB cDNAs were transfected into NIH 3T3 cells and cell clones expressing high levels of RB protein were isolated and characterized. Stable expression of RB protein was obtained, and cell growth experiments indicated that the human RB expressing clones maintained unaltered growth rates under normal culture conditions. The growth rates of wild-type RB-expressing clones but not those expressing mutant RB were reduced in lower serum concentrations. This indicates that serum withdrawal may bring out some growth suppressive properties of RB. Analysis of the human RB protein produced by mouse fibroblasts by cell synchronization and immunoblotting indicated that pRB was phosphorylated and dephosphorylated in a cell cycle-dependent manner. This suggests a functional role for the human pRB also in mouse cells. Moreover, cells expressing wild-type pRB were less susceptible to the transforming effects of SV40 large T antigen than cells expressing mutant pRB as shown by cell transfection studies. The results indicate that human pRB produced by mouse fibroblasts is functionally active and show that pRB can suppress the transforming activity of T antigen.

Age and sex differentials in mortality during two nineteenth century population crises.

"The exceptionally detailed Finnish materials are used to examine age- and sex-specific mortality in different regions during the country's last famine, the Great Famine of the 1860s. This is compared with another mortality crisis, the 1808-09 War. The results show that in cases when multiple infectious diseases were responsible for elevated mortality, the increases for different age categories were, by and large, proportional to the levels prevailing during normal times. However, excess mortality showed more variability for children. Furthermore, age- and sex-specific social behaviour (specifically large-scale temporary migration) during the crisis period shaped the age patterns and sex differentials in mortality." (SUMMARY IN FRE)

Fidelity of DNA synthesis by the Thermococcus litoralis DNA polymerase--an extremely heat stable enzyme with proofreading activity.

We demonstrate that the DNA polymerase isolated from Thermococcus litoralis (VentTM DNA polymerase) is the first thermostable DNA polymerase reported having a 3'----5' proofreading exonuclease activity. This facilitates a highly accurate DNA synthesis in vitro by the polymerase. Mutational frequencies observed in the base substitution fidelity assays were in the range of 30 x 10(-6). These values were 5-10 times lower compared to other thermostable DNA polymerases lacking the proofreading activity. All classes of DNA polymerase errors (transitions, transversions, frameshift mutations) were assayed using the forward mutational assay (1). The mutation frequencies of Thermococcus litoralis DNA polymerase varied between 15-35 x 10(-4) being 2-4 times lower than the respective values obtained using enzymes without proofreading activity. We also noticed that the fidelity of the DNA polymerase from Thermococcus litoralis responds to changes in dNTP concentration, units of enzyme used per one reaction and the concentration of MgSO4 relative to the total concentration of dNTPs present in the reaction. The high fidelity DNA synthesis in vitro by Thermococcus litoralis DNA polymerase provides good possibilities for maintaining the genetic information of original target DNA sequences intact in the DNA amplification applications.

Inbreeding in Finland.

We have compiled data on the frequency of first-cousin marriages in Finland using royal dispensation records for the time period 1810-1872 and national population statistics for the time period 1878-1920. For the earlier period, 0.315% of Finland's marriages were contracted between first cousins (2,331 of 739,387). During the second time period, 0.174% of Finland's marriages took place between first cousins (1,325 of 761,976). These figures, which yield average kinship coefficients of 0.00020 and 0.00011, respectively, show that the level of inbreeding in Finland due to first-cousin marriage has been quite low. An analysis of individual parishes shows that first-cousin marriages are, on average, substantially less frequent than predicted by a random-mating model. In order to evaluate determinants of first-cousin marriage, several predictive variables have been examined: parish ethnic composition (proportion of Swedish and Finnish speakers), husband's occupation (graded into 6 socioeconomic levels), geographic distance between spouses' premarital residences, population density, parish endogamy, and urban vs. rural residence. Various logistic and linear regression models were analyzed in which consanguinity was the dependent variable. The best predictors of consanguinity were ethnic composition and occupation. The other variables were not in general significant predictors. These results show that many of the "mate availability" factors that would be predicted theoretically to account for consanguinity variation (population density, geographic isolation, urban vs. rural residence) do not. Instead, the best predictors of consanguinity at the first-cousin level are cultural factors such as ethnicity and occupation. Evaluation of cultural variables can provide a greatly enriched interpretation of complex biosocial phenomena such as inbreeding.

War demography: the impact of the 1808-09 war on the civilian population of Aland, Finland.

"A pre-industrial population crisis caused by a war is examined using Finnish historical records. During the War of Finland (1808-09) the Swedish military deployed on the Aland Islands helped spread infectious diseases among the civilian population. The result was a short but intense period of high mortality. This article focuses on the short-term demographic impact of this crisis. Changes in age-specific and sex-specific mortality, fertility, and nuptiality are explored....A projection, assuming that the crisis did not occur, indicates that Aland's population losses were never compensated." (SUMMARY IN FRE)

Predicting smallpox epidemics: A statistical analysis of two Finnish populations.

We analysis data on death due to smallpox in two subdivided Finish populations, the relatively isolated Åland Islands and the mainland parish of Kitee. The data span a 135-year time period (1750-1885). Logisitic regression and Cox proportional hazards models are used to assess the effects of predictive variables on (1) the probability that an individual subdivision experiences an epidemic and (2) the length of the time period between two epidemics in each subdivision. The predictive variables include population sizes, migration rates, geographic distance, and presence or absence of vaccination. Vaccination was found to be the single most important predicative variable (odds ratio = 6.3 in Åland and 4.4 in Kitee). No other variable were significant predicators in Kitee, while geographic distance was an additional significant predicator in Åland (odds ratio = 1.05). As expected, vaccination and geographic distance were both negatively associated with the probability of epidemic occurrence. The Mantel regression approach was used to evaluate the effects of independent variables on the probability that any two subdivisions experienced the same epidemic. Between-subdivision migration rates were the most important predictive variable here, and population size was an important predictor in Åland but not in Kitee. The differing results in these two populations are explained in terms of differences in ecological setting and social organization.

Marital migration and genetic structure in Kitee, Finland.

A genetic analysis of marital migration in Kitee, Finland, is presented. The data are based on 9970 marriages which took place between 1750 and 1877. The results of this analysis are compared with those of previous studies of the population of the Aland Islands, Finland. Analysis of inter-subdivision genetic kinship matrices shows that genetic heterogeneity in Kitee is substantially less than in Aland. This is due primarily to higher rates of migration, both between subdivisions and from outside the population, in Kitee compared to Aland. These differences in migration rates can in turn be attributed to greater geographic isolation in Aland and the contrasting social structures of the two populations. Because of differences in geographic structure and population distribution, geographic distance between subdivisions is a better predictor of inter-subdivision genetic kinship in Kitee than in Aland. The Aland Islands are known to have high frequencies of several otherwise rare genetic diseases; in addition, these diseases are distributed very non-randomly among Aland's subdivisions. The genetic structure results presented here suggest that Kitee should have a less unique distribution of genetic diseases.