Biomedical subjects

Mukaddes Gölge

Publications and source records attributed to Mukaddes Gölge.

9 recordsLinked to original sources

PubMed2005

Evaluating the forensic informativeness of mtDNA haplogroup H sub-typing on a Eurasian scale.

The impact of phylogeographic information on mtDNA forensics has been limited to the quality control of published sequences and databases. In this work we use the information already available on Eurasian mtDNA phylogeography to guide the choice of coding-region SNPs for haplogroup H. This sub-typing is particularly important in forensics since, even when sequencing both HVRI and HVRII, the discriminating power is low in some Eurasian populations. We show that a small set (eight) of coding-region SNPs resolves a substantial proportion of the identical haplotypes, as defined by control-region variation alone. Moreover, this SNP set, while substantially increasing the discriminating efficiency in most Eurasian populations by roughly equal amounts, discloses population-specific profiles.

Asia↗

PubMed2005

High-resolution mtDNA evidence for the late-glacial resettlement of Europe from an Iberian refugium.

The advent of complete mitochondrial DNA (mtDNA) sequence data has ushered in a new phase of human evolutionary studies. Even quite limited volumes of complete mtDNA sequence data can now be used to identify the critical polymorphisms that define sub-clades within an mtDNA haplogroup, providing a springboard for large-scale high-resolution screening of human mtDNAs. This strategy has in the past been applied to mtDNA haplogroup V, which represents <5% of European mtDNAs. Here we adopted a similar approach to haplogroup H, by far the most common European haplogroup, which at lower resolution displayed a rather uninformative frequency distribution within Europe. Using polymorphism information derived from the growing complete mtDNA sequence database, we sequenced 1580 base pairs of targeted coding-region segments of the mtDNA genome in 649 individuals harboring mtDNA haplogroup H from populations throughout Europe, the Caucasus, and the Near East. The enhanced genealogical resolution clearly shows that sub-clades of haplogroup H have highly distinctive geographical distributions. The patterns of frequency and diversity suggest that haplogroup H entered Europe from the Near East approximately 20,000-25,000 years ago, around the time of the Last Glacial Maximum (LGM), and some sub-clades re-expanded from an Iberian refugium when the glaciers retreated approximately 15,000 years ago. This shows that a large fraction of the maternal ancestry of modern Europeans traces back to the expansion of hunter-gatherer populations at the end of the last Ice Age.

DNA, Mitochondrial↗

PubMed2004

Hand coordination following capsular stroke.

Motor outcome following stroke of the internal capsule is variable and its determinants are poorly understood. While many patients fully regain their abilities, recovery of motor functions remains incomplete in others. We analysed functional motor tasks of the upper limb to determine the pattern of focal disability after a small infarct of the internal capsule ('pure motor stroke') in the chronic stage (mean 2.4 years after stroke) with kinematic recordings of a reaching-to-grasp movement, with a quantitative analysis of the precision grip, and with clinical rating scales. The location of the lesions within the posterior limb of the internal capsule (PLIC) in 18 patients was determined from neuroimages obtained in the acute stage (5-20 days after the insult). Involvement of the PLIC was assessed at the level of the basal ganglia, approximately 8 mm above the anterior commissure-posterior commissure level. The distance between the posterior edge of the internal capsule and the centre of gravity of the lesion was determined. Chronic disabilities affected dextrous movements, while paresis was mild and sensitivity for light touch or passive finger flexion was almost normal. For both the reaching-to-grasp movement and the precision grip paradigm, the slowness of movement or force development was confined to the phases when grip formation and stabilization occur, while the onset of hand transport and of the vertical lifting force were not delayed. Grip forces were increased. We observed a close correlation between posterior location within the PLIC and the altered measures of timing and precision grip force. The more posterior the acute lesion was located within the PLIC, the more pronounced were the chronic motor deficits, as seen both in the quantitative measures and in the rating scales. The present study demonstrates for the first time that the amount and quality of chronic motor deficits of dextrous movements are related to a simple measure drawn from routine neuroimaging in the acute stage in patients with capsular stroke. The poor motor outcome in lesions involving the most posterior parts of the PLIC could be due to the condensed organization of corticofugal projections and the density of pyramidal fibres from the primary motor cortex in this subsector. Even small infarcts of this strategic area can disrupt many of the projections from the motor cortices and could thereby limit recovery strategies between homolateral motor representations.

Adult↗

PubMed2004

Disuniting uniformity: a pied cladistic canvas of mtDNA haplogroup H in Eurasia.

It has been often stated that the overall pattern of human maternal lineages in Europe is largely uniform. Yet this uniformity may also result from an insufficient depth and width of the phylogenetic analysis, in particular of the predominant western Eurasian haplogroup (Hg) H that comprises nearly a half of the European mitochondrial DNA (mtDNA) pool. Making use of the coding sequence information from 267 mtDNA Hg H sequences, we have analyzed 830 mtDNA genomes, from 11 European, Near and Middle Eastern, Central Asian, and Altaian populations. In addition to the seven previously specified subhaplogroups, we define fifteen novel subclades of Hg H present in the extant human populations of western Eurasia. The refinement of the phylogenetic resolution has allowed us to resolve a large number of homoplasies in phylogenetic trees of Hg H based on the first hypervariable segment (HVS-I) of mtDNA. As many as 50 out of 125 polymorphic positions in HVS-I were found to be mutated in more than one subcluster of Hg H. The phylogeographic analysis revealed that sub-Hgs H1*, H1b, H1f, H2a, H3, H6a, H6b, and H8 demonstrate distinct phylogeographic patterns. The monophyletic subhaplogroups of Hg H provide means for further progress in the understanding of the (pre)historic movements of women in Eurasia and for the understanding of the present-day genetic diversity of western Eurasians in general.

Asia↗

PubMed2004

Recovery of the precision grip in children after traumatic brain injury.

OBJECTIVE: To identify quantitative parameters that are sensitive enough to detect impairments and improvements of grasping in children after traumatic brain injury (TBI) by analyzing the isometric fingertip forces of a precision grip-lift task. DESIGN: Follow-up and case-control study. SETTING: Tertiary pediatric trauma rehabilitation center in Germany. PARTICIPANTS: Thirteen children (age range, 5-14 y) with moderate or severe TBI. Trauma severity was assessed with the Glasgow Coma Scale (score range, 3-9) and the Injury Severity Score (range, 16-66 points). Control data were obtained from 13 age- and gender-matched healthy children. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Children were examined 3 times (t0, t1, t2). The first date of examination (t0) was defined by the Barthel Index (part B, >20 points). Reexaminations followed after 1 (t1) and 5 (t2) months of inpatient rehabilitation. Quantitative measures included 3 grip-force parameters, 2 load force parameters, 1 parameter of the coordination between grip force and load force, and 3 timing parameters in a precision grip-lift task. Clinical improvements and recovery of activities of daily living were described with the Barthel Index (qualitative measure). RESULTS: Peak grip force, maximum negative load force, grip force in the static phase and its standard deviation, and grip-force/load-force ratio at maximum grip force showed significant improvements during the observation period (5 mo). Also, the preparation phase and preload duration, but not the load duration, changed significantly. CONCLUSIONS: Impairments and the recovery of grasping in children after TBI can be objectified with quantitative analyses of the precision grip. Several grip-force and timing parameters were sensitive for the description of restitution processes.

Activities of Daily Living↗

PubMed2003

Subthalamic nucleus stimulation for Parkinson's disease preferentially improves akinesia of proximal arm movements compared to finger movements.

Deep brain stimulation of the subthalamic nucleus (STN-DBS) reduces akinesia in Parkinson's disease but its impact on fine motor functions was unknown. We assessed the effects of DBS and a levodopa (L-dopa) test on the timing of the precision grip in 18 patients. Improvement on UPDRS-items reflecting hand functions and the shortening of the first phases of the precision grip were more distinct in the L-dopa test than in the pure STN-DBS condition. Other akinesia items and the time for build-up of lifting force were equally improved in both conditions. This suggests that routine STN-DBS might not be equally effective on all aspects of fine motor functions.

Antiparkinson Agents↗

PubMed2003

Sensorimotor recovery in children after traumatic brain injury: analyses of gait, gross motor, and fine motor skills.

The recovery of gait, gross motor proficiency, and hand function was examined in 23 children (13 males, 10 females; age 4 years 7 months to 15 years 10 months) with traumatic brain injury (TBI) over five months of in patient rehabilitation. We used gait analysis, the Gross Motor Function Measure, the Developmental Hand Function Test, and the Purdue Pegboard test. Brain injury had been severe (initial Glasgow Coma Scale GCS <8) in 17 children and moderate (GCS 8-10) in six children. Compared with healthy control children of the same age and sex, repeated gait analyses in ambulatory children with brain injury showed significant reductions of velocity, stride length and cadence, and impaired balance. Spatiotemporal gait variables were correlated with Gross Motor Function Measure scores. Hand function tests revealed deficits in fine motor skills, speed, and coordination. Degree of impairment increased with trauma severity. Despite significant improvements, differences in gait velocity, stride length, and hand function of children with brain injuries and controls were still present about 8 months after TBI. Hand motor skills improved less than gait. Young age at injury was not associated with better recovery.

Adolescent↗

PubMed2003

Analyses of gait, reaching, and grasping in children after traumatic brain injury.

OBJECTIVE: To evaluate motor behavior in children after traumatic brain injury (TBI) with quantitative instrumented measures of gait and of functional hand movements (reaching, grasping) and with clinical assessments. DESIGN: Case-control study. SETTING: Tertiary pediatric trauma rehabilitation center in Germany. PARTICIPANTS: Twenty children (age range, 6-13 y) with moderate or severe TBI were examined 1+/-1.2 years (mean +/- standard deviation) postinjury. Fifteen were reexamined 2 months later. Control data were obtained from 20 healthy children and matched for age, gender, and school grade. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Quantitative measures included 10 spatiotemporal gait parameters and 6 variables describing reaching and grasping. Qualitative scores of gait and upper-limb movements were also obtained. RESULTS: Gait velocity and step and stride lengths were significantly smaller in children after TBI than in control subjects (Mann-Whitney U test, P<.05). Reach-to-grasp movements of the TBI children were characterized by a significantly longer reaction time (Mann-Whitney U test, P<.05) and movement duration, reduced velocity, and coordination deficits. The instrumented measures did not change significantly in 2 months. Several significant correlations between clinical and instrumented measures were obtained. CONCLUSION: Functional motor behavior is affected in children after moderate or severe TBI. To supplement clinical assessments with objective data, impairments of gait, reaching, and grasping movements can be recorded with instrumented measures.

Adolescent↗

PubMed2000

Prenatal infarction of the left middle cerebral artery: A case report of excellent functional outcome.

Extensive cortical-subcortical damage of the left hemisphere, most likely due to prenatal infarction of the left middle cerebral artery, was accidentally detected in a 12-year-old left-handed girl. Since clinical symptoms were minimal, the lesion had not been discovered for more than a decade. Meticulous examination revealed some slowness and somatosensory deficits of the right hand. Yet, independent finger movements were preserved, and functional skills such as reaching and grasping were unimpaired, as documented with optoelectronic motion analysis. There were no mirror movements. Transcranial magnetic stimulation indicated that the right hand was controlled by spared cortical areas of the damaged hemisphere. Gait was normal. Neuropsychological examination confirmed regular development of language, intellect, and visuospatial abilities. This case report demonstrates exceptionally good functional outcome after early brain damage.

Journal Article↗