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Biomedical subjects

S Zierz

Publications and source records attributed to S Zierz.

At least 19 recordsLinked to original sources
PubMed2003

[Rhabdomyolysis and myoglobinuria].

Rhabdomyolysis is a disorder characterized by acute damage of the sarcolemma of the skeletal muscle leading to release of potentially toxic muscle cell components into the circulation, most notably creatine phosphokinase (CK) and myoglobin, and is frequently accompanied by myoglobinuria. Therefore, the term myoglobinuria is often used interchangeably with the term rhabdomyolysis. This disorder may result in potential life-threatening complications such as acute myoglobinuric renal failure, hyperkalemia and cardiac arrest, disseminated intravascular coagulation, and compartment syndrome. The condition is etiologically heterogeneous and may result from a large variety of diseases affecting muscle membranes, membrane ion channels, and muscle energy supply including acquired causes (e.g., exertion, crush injury and trauma, alcoholism, drugs, and toxins) and hereditary causes (e.g., disorders of carbohydrate metabolism, disorders of lipid metabolism, or diseases of the muscle associated with malignant hyperthermia). In many patients with idiopathic recurrent rhabdomyolysis, specific inherited metabolic defects have not been recognized up to now.

AMP Deaminase↗
PubMed2003

Late-onset encephalopathy associated with a C11777A mutation of mitochondrial DNA.

A 67-year-old man presented with cognitive deficits, status epilepticus, left hemiparesis, and severe lactic acidosis. Respiratory chain enzyme analysis of skeletal muscle revealed a defect in complex I activity, associated with a heteroplasmic C11777A mutation in the mitochondrial ND4 gene. This case is remarkable not only because of the late onset of symptoms, but because this mutation affects the identical ND4 codon as the G11778A mutation that causes Leber hereditary optic neuropathy.

Acidosis, Lactic↗
PubMed2003

Carnitine palmitoyltransferase II deficiency: molecular and biochemical analysis of 32 patients.

The authors investigated 32 patients with the muscle form of CPT II deficiency. Total carnitine palmitoyltransferase enzyme system (CPT) activity was normal but abnormally inhibited by malonyl-CoA, palmitoyl-CoA, and the detergents Triton X and Tween 20. Mutation analysis identified three described mutations (S113L, P50H, and F448L) and two novel mutations (M214T and Y479F). Using modeling techniques, a structure could be identified anchoring the protein in the membrane. Only one of the five mutations (Y479F) is located within this region.

Amino Acid Sequence↗
PubMed2003

[Facioscapulohumeral muscular dystrophy. The spectrum of clinical manifestations and molecular genetic changes].

Although the gene for facioscapulohumeral muscular dystrophy (FSHD) has not been identified so far, 4q35 deletion represents a diagnostic marker of the disease. In the present study, 46 consecutive symptomatic patients with 4q35 FSHD deletions or typical FSHD clinical features were evaluated. The patients were divided into three groups: 33 patients (72%) with typical FSHD phenotype and 4q35 FSHD deletion, eight (17%) with atypical (non-Landouzy-Dejerine) FSHD phenotype but with 4q35 FSHD deletion, and five patients (11%) with the typical FSHD phenotype but without FSHD 4q35 deletion. Apparently, the 4q35 deletion is associated not only with Landouzy-Dejerine FSHD but also with a variety of "atypical" FSHD forms. On the other hand, the Landouzy-Dejerine FSHD phenotype is possibly a polyetiological syndrome caused in some patients by other genetic effects than 4q35 deletion.

Adolescent↗
PubMed2003

[Age dependence of Doppler parameters in the basal cerebral arteries evaluated by transcranial color-coded duplex sonography. Reference data from 290 volunteers].

AIM: In this study the Doppler parameters of the basal intracranial arteries and the insonation in axial and coronary plane by temporal approach were established in healthy volunteers of all age groups with transcranial color-coded duplex sonography (TCDS). METHODS: 290 healthy probands (age 0 to 91 years) were investigated through the temporal and transnuchal ultrasound window. The angle corrected flow velocities and the resistance indices of the basal brain arteries were measured. RESULTS: The flow velocities rapidly increase in children (from 3 years up to puberty) and gradually decrease with increased age. Vice versa, the resistance indices decrease in children and increase in older people. The flow velocities show significant differences by axial and coronary insonation in certain arteries of the circle of Willis. CONCLUSION: The Doppler parameters of the basal intracranial arteries evaluated with TCDS depend from age. The flow velocities and resistance indices are similar in children and older people. The coronary transtemporal approach is considered a useful completion of the axial investigation.

Adolescent↗
PubMed2003

[Classical crossed syndromes of the medulla oblongata. A historical and topodiagnostic discussion].

Historical publications of the classical alternating medulla oblongata syndromes of Wallenberg, Babinski-Nageotte, Cestan-Chenais, Hughlings Jackson, Avellis, Schmidt, Dejerine, Spiller and Tapia were reviewed and critically analysed. We compare these descriptions with descriptions of the brainstem syndromes in well-known modern German, English and Russian neurological textbooks. The anatomic basis and etiology of the alternating medullar syndromes, and the main publications relating to these syndromes were discussed. Causes of the inconsistencies of the modern and historical descriptions of these syndromes might be an ignorance of the historical references. Progress and development of the clinical neurology and neuroanatomy in the late twentieth century, however, has also lead to correction and perfection of some historical descriptions in the modern neurological literature.

Brain Diseases↗
PubMed2002

Brainstem infarctions with normal MRI.

Most studies on brainstem infarctions included only patients with lesions documented by CT or MRI. The aim of this study was to analyse the clinical symptomatology in patients with the classical signs of brainstem infarcts and normal MRI results. Frequencies of MR-positive and negative infarctions should be analysed according to their location. In a series of 30 consecutive patients with acute clinical symptoms of ischemic brainstem lesions and persistence of the symptomatology for more than 10 days, 8 patients had normal MRI. In these patients the location of the lesion was established by clinical and electrophysiological criteria. The lesions in the 8 patients with normal MRI were situated in medulla oblongata (n=3), in pons (n = 2), and in midbrain (n = 3). In each of these patients the clinical symptoms corresponded to one of the classical alternating syndromes, which are pathognomic for brainstem infarctions (1 Wallenberg, 1 Avellis, 1 Jackson, 2 Millard-Gubler, and 3 Weber). The clinical course of the infarctions with normal MRI was favourable, the symptoms disappeared within few weeks. Our study proved that the clinical diagnosis of brainstem infarction, particularly in lesions of midbrain and caudal tegmentum pontis, can not be excluded by normal MRI.

Aged↗
PubMed2002

[Hauptmann-Thannhauser muscular dystrophy and differential diagnosis of myopathies associated with contractures].

Hauptmann-Thannhauser muscular dystrophy is characterized by the clinical triad of early-onset contractures of elbow, Achilles tendons, and cervical spine, slowly progressive humeroperoneal muscle wasting and weakness, and life-threatening cardiac involvement with conduction blocks manifesting in the third decade. Hauptmann-Thannhauser muscular dystrophy is due to mutations in the LMNA gene affecting the nuclear envelope proteins lamin A and C. We present a 16-year-old German boy with typical muscular involvement and contractures and typical course of Hauptmann-Thannhauser muscular dystrophy due to the novel missense mutation R401C. The data of this family suggest a lower penetrance of muscular and especially cardiac symptoms than expected. Autosomal-dominant Hauptmann-Thannhauser muscular dystrophy and X-chromosomal Emery-Dreifuss muscular dystrophy are not clearly distinguishable by phenotypic criteria. Other muscular diseases associated with contractures and congenital or childhood onset are reviewed.

Adolescent↗
PubMed2001

Lack of dystrophin is associated with altered integration of the mitochondria and ATPases in slow-twitch muscle cells of MDX mice.

The potential role of dystrophin-mediated control of systems integrating mitochondria with ATPases was assessed in muscle cells. Mitochondrial distribution and function in skinned cardiac and skeletal muscle fibers from dystrophin-deficient (MDX) and wild-type mice were compared. Laser confocal microscopy revealed disorganized mitochondrial arrays in m. gastrocnemius in MDX mice, whereas the other muscles appeared normal in this group. Irrespective of muscle type, the absence of dystrophin had no effect on the maximal capacity of oxidative phosphorylation, nor on coupling between oxidation and phosphorylation. However, in the myocardium and m. soleus, the coupling of mitochondrial creatine kinase to adenine nucleotide translocase was attenuated as evidenced by the decreased effect of creatine on the Km for ADP in the reactions of oxidative phosphorylation. In m. soleus, a low Km for ADP compared to the wild-type counterpart was found, which implies increased permeability for that nucleotide across the mitochondrial outer membrane. In normal cardiac fibers 35% of the ADP flux generated by ATPases was not accessible to the external pyruvate kinase-phosphoenolpyruvate system, which suggests the compartmentalized (direct) channeling of that fraction of ADP to mitochondria. Compared to control, the direct ADP transfer was increased in MDX ventricles. In conclusion, our data indicate that in slow-twitch muscle cells, the absence of dystrophin is associated with the rearrangement of the intracellular energy and feedback signal transfer systems between mitochondria and ATPases. As the mechanisms mediated by creatine kinases become ineffective, the role of diffusion of adenine nucleotides increases due to the higher permeability of the mitochondrial outer membrane for ADP and enhanced compartmentalization of ADP flux.

Adenosine Diphosphate↗
PubMed2001

Evidence for a mitochondrial oxidative phosphorylation defect in brains from patients with schizophrenia.

In-vivo imaging studies and post-mortem studies have demonstrated an impairment of energy metabolism in brains of patients with schizophrenia. Decreased oxidative metabolism has been consistently documented in the frontal lobes. However, the biochemical basis of these changes is unclear. The changes could be caused by reduced requirement of the cells for metabolic energy or an abnormality in energy generation. Neurons generate energy through the respiratory chain in the mitochondria. The respiratory chain consists of five enzyme complexes (I-V). The purpose of the present study was to assess mitochondrial function and test the hypothesis of an underlying oxidative phosphorylation defect in schizophrenia. We analysed spectrophotometrically post-mortem brain specimens of frontal cortex, temporal cortex, basal ganglia, and cerebellum of 12 patients who met the DSM-IV criteria for schizophrenia and of 13 healthy controls for the specific activities of respiratory chain enzymes in the mitochondria. The major finding was that the activity of complex IV was significantly reduced in the frontal cortex (40.9+/-6.7 vs. 87.3+/-12, P=0.003) and in the temporal cortex (39.5+/-6.8 vs. 78+/-10.8, P=0.006) of schizophrenics. In addition, the activity of complexes I+III was significantly reduced in the temporal cortex (2.2+/-0.6 vs. 4.4+/-0.5, P=0.01) and basal ganglia (1.6+/-0.5 vs. 3.4+/-0.3, P=0.015) in schizophrenia. All other enzyme activities showed no differences to healthy controls. The results confirm a defect of oxidative phosphorylation in brains from patients with schizophrenia, which may contribute to impaired energy generation.

Aged↗
PubMed2001

Hearing impairment is common in various phenotypes of the mitochondrial DNA A3243G mutation.

OBJECTIVE: To determine whether there are common symptoms within different phenotypes of the mitochondrial DNA A3243G mutation. DESIGN: A series of 52 adults with mitochondrial encephalomyopathies and their symptomatic relatives were screened for the A3243G mutation using restriction enzyme analysis. In addition to clinical examination, patients with the mutation underwent audiometry. RESULTS: The A3243G mutation was identified in 16 patients (10 index patients and 6 symptomatic relatives). Six of these patients presented with strokelike episodes and met the classical criteria of MELAS syndrome (mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes), and one had MELAS/MERRF (myoclonic epilepsy with ragged-red fibers) overlap syndrome. Two patients presented with strokelike episodes but did not meet the classical criteria of MELAS. Predominant features of the 8 other patients were myopathy with hearing loss and diabetes mellitus (n = 1), chronic progressive external ophthalmoplegia (n = 1), diabetes mellitus with hearing loss (n = 1), painful muscle stiffness with hearing loss (n = 1), cardiomyopathy (n = 1), diabetes mellitus (n = 1), and hearing loss (n = 2). In 11 of 16 patients, hearing impairment was obvious on clinical examination. Furthermore, all 5 patients with normal hearing on clinical examination showed subclinical hearing loss; in 4, hearing loss was more pronounced than age-related hearing impairment and in 1, hearing loss can be age related as well. CONCLUSIONS: A variety of phenotypes represent the variable multisystemic involvement of the A3243G mutation. Less than half of the patients presented with MELAS. Hearing impairment, the most common symptom, was clinically or subclinically relevant in 15 (94%) of 16 patients.

Adolescent↗
PubMed2001

GCG repeats and phenotype in oculopharyngeal muscular dystrophy.

Short GCG repeat expansions in the PABP2 gene were recently shown to cause oculopharyngeal muscular dystrophy (OPMD) in French-Canadian and Italian pedigrees. We diagnosed OPMD in 16 German patients by the detection of GCG repeat expansions, confirming genetic homogeneity. Myopathic and neurogenic changes were found in skeletal muscle biopsies. Age of onset and severity of disease were not correlated with the number of repeats.

Age of Onset↗
PubMed2001

Discharge patterns of spontaneous activity and motor units on concentric needle electromyography.

We analyzed discharge patterns in electromyograms of 6 patients with complete nerve lesions and of 26 healthy subjects, in order to better differentiate between pathological and physiological spontaneous electromyographic (EMG) activity. Within 1639 trains of action potentials, the intervals between at least five successive discharges were measured. Discharge regularity was evaluated with three different algorithms. At 99% specificity, an abnormal discharge pattern was identified with 91 to 95% sensitivity, depending on the algorithm used. Analysis of as few as four successive interdischarge intervals allowed reliable differentiation between normal and pathological spontaneous EMG activity.

Action Potentials↗
PubMed2001

Length dependence of variables associated with temporal dispersion in human motor nerves.

Temporal dispersion in motor nerves is associated with changes of amplitude, area, duration, and Fourier spectra of compound muscle action potentials (CMAPs) when comparing responses to proximal and distal stimulation. These changes depend on the length of the nerve segment. To quantitatively assess this dependence, motor conduction studies of nerve segments of various lengths were performed in the median, ulnar, and tibial nerves of 86 test subjects, aged 4 to 73 years. Amplitude, area, duration, and spectral energy above 49 Hz of CMAPs were measured. Values after distal and proximal stimulation of each nerve segment were compared to determine amplitude decay, area decay, protraction, and high-frequency attenuation. A significant length dependence of amplitude decay was found in the tibial and ulnar nerves, of area decay in the median and ulnar nerves, and of CMAP duration in the ulnar and tibial nerves. The length dependence of the high-frequency attenuation was significant in all nerves studied. This report provides normative data for variables associated with temporal dispersion.

Action Potentials↗