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S Zierz

Publications and source records attributed to S Zierz.

At least 91 records · Page 5Linked to original sources
PubMed1998

Carnitine acyltransferases are not changed in Alzheimer disease.

We evaluated the activities of carnitine palmitoyltransferase (CPT), carnitine octanoyltransferase (COT), and carnitine acetyltransferase (CAT) in the frontal cortex, temporal cortex, parietal cortex, hippocampus, and cerebellum of Alzheimer disease (AD) patients and normal human brains. There were no significant differences in total CPT activity, its inhibition by malonyl-CoA, the effect of the detergent Triton X-100 on CPT activity, COT activity, and CAT activity in any of the brain regions examined whether activities were expressed as grams of wet weight or corrected for noncollagen protein content. The addition of Triton X-100 increased CAT activity by 50%. Our results suggest that there is no defect of fatty acid transport within the AD brain cell. Total CPT activity, COT activity, and CAT activity are not affected in AD nor is the ratio of CPT I to CPT II altered in the AD versus the normal human brain.

Aged↗
PubMed1998

Automated intraoperative detection of Doppler microembolic signals using the bigate approach.

BACKGROUND AND PURPOSE: We undertook this study to evaluate the performance of an automated detection software in the detection of Doppler microembolic signals (MES) during cardiac surgery. METHODS: Intraoperative monitoring was performed over two spatially separated vessel segments of each middle cerebral artery in 18 patients undergoing coronary artery bypass surgery (n= 16) or cardiac valve replacement (n=2). All monitoring sessions were saved on digital audiotape and subsequently played back to the same ultrasound machine, set up to automatically detect MES by evaluating the temporary delay in their appearance between the two segments, in the presence of an experienced examiner. Software sensitivity and specificity in MES detection were then evaluated, with the results of the human observer considered the gold standard. RESULTS: A total of 44,933 high-intensity signals (artifacts and MES) were evaluated. Overall sensitivity and specificity of the software, with the human observer considered the gold standard, were 64% and 78.5%, respectively, ranging from 54% to 96% and from 74% to 90% in individual patients. When the overall results of the software were compared with those of the human observer, kappa was 0.72. CONCLUSIONS: The tested software displayed a satisfactory specificity. Provided that the sensitivity is further improved, it could provide a valuable tool in intraoperative monitoring.

Artifacts↗
PubMed1997

Identification of Doppler microembolic signals with a bigate probe in patients with prosthetic heart valves.

BACKGROUND AND PURPOSE: The applicability of a bigate probe, simultaneously harvesting two spatially separated vessel segments, in the identification of Doppler microembolic signals (MES) was evaluated. METHODS: One hundred and ninety-seven patients with artificial heart valves were bilaterally monitored over two segments of each middle cerebral artery, with a minimal distance of 5 mm between them, using 2 MHz probes. Time delay in the appearance of high intensity transients between the two segments was calculated off-line, using dedicated software, integrated in the Doppler device. RESULTS: Bigate monitoring was feasible in 96% of patients. MES prevalence and counts were 37% and 26 (18-44) respectively. All but 8.8% of the 2932 MES signals recorded appeared in both Doppler channels, with a time delay of 4.4 (4.2-4.7) msec (range between 0 and 34 msec). Time delay in 97% of artifact signals was under 1 msec. Application of 1 msec as low and 20 msec as high cut-off point between MES and artifacts resulted in the correct identification of 97% of artifacts and 89.6% of MES. CONCLUSIONS: The multigate approach is a reliable method for identification of Doppler microembolic signals in patients with prosthetic heart valves. The value of this technique in other patient groups remains to be evaluated.

Aortic Valve↗
PubMed1997

[Differential sciatica pain diagnosis from the neurologic viewpoint].

Low back pain and sciatica with or without neurological deficits represent frequent disorders in clinical practice. Both, history and neurological examination are essential for localizing underlying lesions and initiating appropriate investigations. Pain location, sensory symptoms, motor signs and reflexes are extremely reliable in indicating which motor root(s) or peripheral nerve(s) are affected. Sometimes, pain and/or paraesthesia are the only presenting symptoms. Therefore differential diagnosis of low back pain and sciatica is various. This article summarizes the differential diagnosis of low back pain and sciatica according to the site of the lesion as follows: 1. lesions of the spinal cord, 2. lesions of the nerve roots (L4, L5, S1-S3), 3. lesions of the lumbosacral plexus, 4. peripheral nerve lesions (sciatic nerve, peroneal nerve), 5. low back pain and sciatica due to neuropathies, and 6. low back pain and sciatica as a symptom of other neurological disorders. Additionally, the status of neuroradiological procedures in establishing diagnosis is discussed.

Diagnosis, Differential↗
PubMed1997

Purification and characterization of human sarcomeric mitochondrial creatine kinase.

In order to set the basis for detailed clinical investigations, mitochondrial creatine kinase (Mi-CK) was purified to homogeneity from human cardiac muscle. Biophysical characterization by SDS-PAGE, gel permeation chromatography and by electron microscopy of negatively stained single molecules demonstrated that, similar to other vertebrate Mi-CKs, human sarcomeric Mi-CK occurs in two different oligomeric forms, dimers and octamers, that are readily interconvertible. The apparent MTs of Mi-CK protomers, dimers and octamers were 43,600 +/- 800, 79,700 +/- 800 and 371,000 +/- 3000, respectively. In addition, isoelectric focussing proved to be a suitable technique for routinely distinguishing Mi-CK from cytosolic MM-CK and gave pl values of 8.30 +/- 0.04 and 7.44 +/- 0.04 for octameric and dimeric human sarcomeric Mi-CK. Circumstantial evidence suggests that both the highly symmetrical structure and the high pI value of Mi-CK octamers are crucial determinants for the physiological functions of this enzyme.

Creatine Kinase↗
PubMed1997

[Proximal myotonic myopathy (PROMM). Clinical variability within a family].

Proximal myotonic myopathy (PROMM) is a newly described autosomal dominant inherited disorder characterized by predominant proximal weakness of the legs, mild clinical myotonia or myotonia on electromyograms (EMG), cataracts and slight elevation of liver enzymes. The trinucleotide (cytosine, thymine, and guanine) repeat size of the myotonic dystrophy (DM) gene is normal. Magnetic resonance imaging of the brain may reveal a peculiar pattern of white matter abnormalities. We describe seven patients in a new family with PROMM. The only symptoms may be subclinical myotonic changes in the EMG or cataracts, but symptoms may also include severe proximal weakness of the legs and painful paraesthesia. PROMM is an important differential diagnosis of myotonic dystrophy; and because of the proximal weakness it is also a differential diagnosis of other muscle diseases such as limb girdle dystrophy, metabolic and endocrine myopathies, and myositis. Because of the variability of the symptoms, for the definite diagnosis of PROMM it may require the examination of other family members.

Adult↗
PubMed1997

Influence of oxygen ventilation on Doppler microemboli signals in patients with artificial heart valves.

BACKGROUND AND PURPOSE: The purpose of this study was to evaluate the influence of inhalation of 100% oxygen on microembolic signal (MES) counts in patients with artificial cardiac valves. METHODS: A total of 134 outpatients were examined. Transcranial Doppler baseline monitoring (45-minute duration) was performed in all patients under resting conditions. The first 30 patients subsequently underwent transcranial Doppler monitoring for at least 20 minutes under noninvasive positive pressure ventilation with 100% oxygen and for an additional 30 minutes under resting conditions. The same protocol was applied to all following patients with a baseline MES count > or = 10, while the examination was discontinued in the remaining patients. RESULTS: Baseline MES counts < 10, which remained unchanged during oxygen inhalation and the subsequent resting period, were observed in 26 of 30 initial patients. A total of 46 patients with MES counts > or = 10 were identified. Oxygen application was feasible in 43 patients. An exponential MES decrease was noted in 42 patients during oxygen inhalation (statistically significant in 38 patients), followed by a subsequent increase in 38 of 43 patients (statistically significant in 25 patients) under resting conditions. CONCLUSIONS: The exponential reduction of MES counts observed in this study corresponds to blood denitrogenation, thus strongly arguing for nitrogen bubbles as underlying embolic material in prosthetic valve carriers.

Adolescent↗
PubMed1997

Doppler microembolic signals in children with prosthetic cardiac valves.

BACKGROUND AND PURPOSE: The aim of this study was the evaluation of the prevalence and counts of Doppler microembolic signals (MES) in children with prosthetic cardiac valves and their comparison to those obtained in corresponding adult patients. PATIENTS AND METHODS: Nine children and 43 adults with ATS valves implanted in the aortic position were monitored over both middle cerebral arteries with transcranial Doppler ultrasound. MES were identified on-line according to standard criteria. Heart rate and rhythm, valve type, size and duration, patients' height, International Normalized Ratio, and prevalence of neurological complications were obtained from all study participants. RESULTS: MES prevalence and counts were significantly higher in children compared with adult patients (100% versus 25.5% and 58 [18.5 to 115.5] versus 55 [2 to 10.5], median, 95% CI, respectively). No corresponding differences in valve duration of valve implant were evident, but children has heart rates and were significantly smaller compared with adults. A positive correlation between patients' size, heart rate, and MES counts was noted. CONCLUSIONS: MES counts in children with mechanical prosthetic valves are significantly higher compared with those in corresponding adults. We hypothesize that this is due to (1) the shorter distance between aortic valve and middle cerebral artery, since cavitation bubbles have a short life span and are bound to dissolve with time, and (2) the faster heart rate in children, resulting in a higher number of valve closures per minute.

Adolescent↗
PubMed1997

Testicular dysfunction in adrenomyeloneuropathy.

Adrenomyeloneuropathy (AMN) is a disorder due to a disturbance in the peroxisomal beta-oxidation of saturated very long chain fatty acids. It is characterized by symptoms of the nervous as well as the endocrine systems, especially the adrenal cortex and the gonads. We investigated the testicular function in 49 male AMN patients aged 36.2 +/- 1.5 years (range, 18.5-59 years). Twenty-four of these patients were suffering from adrenocortical insufficiency. Twenty-five AMN patients showed neurological symptoms without 'Addison's disease'. To register the frequency and the degree of gonadal impairment, LH and FSH, testosterone, free testosterone and inhibin-B were determined. Gonadotropin concentrations were significantly higher in AMN patients than in healthy controls (LH, 8.0 +/- 1.2 vs 2.77 +/- 0.11 IU/l; FSH, 10.1 +/- 1.6 vs 4.0 +/- 0.17 IU/l; P < 0.001). Serum LH was elevated in 31 patients (63.3%); 28 patients (57.1%) showed elevated serum FSH indicating deficient spermatogenesis. Mean testosterone did not differ significantly between patients and healthy controls, but mean free testosterone was significantly lower in patients than in controls (16.3 +/- 1.0 vs 28.5 +/- 1.68 pg/ml, P < 0.002). Inhibin-B concentrations did not differ between AMN patients and healthy men. The testosterone/LH ratio reflecting an impairment of the Leydig cells was significantly lower in AMN patients than in controls (P < 0.01). An impairment of the Leydig cells and/or of the Sertoli cells was evident in 81.6% of AMN patients. Twenty-one of thirty-nine patients (53.8%) admitted erectile dysfunction. These data indicate that endocrine dysfunction in AMN is not only confined to adrenocortical functions, but testicular dysfunctions also frequently occur, thus permitting the term 'adreno-testiculo-myelo-neuropathy'.

Adolescent↗
PubMed1997

[Postpartum obturator nerve syndrome: case report and review of the nerve compression syndrome during pregnancy and delivery].

Compression of a peripheral nerve or nerve trunk can occur during pregnancy and delivery. The injury may be caused by the fetal head, the application of forceps, trauma or hematoma due to cesarean section, or improper positioning in leg holders. Often, no cause of the injury is found. The most common nerve compression syndromes during pregnancy and delivery are carpal tunnel syndrome, femoral neuropathy, and post partal foot drop. Obturator neuropathy, meralgia paraesthetica, tarsal tunnel syndrome, and syndrome of the rectus abdominis muscle occur less frequently. Symptoms, such as paraesthesia, pain and palsies not always attract the immediate attention of the physician. Sometimes they are misinterpreted as nervous complaints. Often, remission is reached at delivery. A case of obturator neuropathy after delivery is reported, and literature on clinical, pathophysiological and electrophysiological findings in maternal obstetric palsies is reviewed.

Adult↗
PubMed1997

Time course of high-intensity transient signals in patients undergoing elective heart valve replacement: a prospective study.

BACKGROUND AND AIMS OF THE STUDY: This study was performed to evaluate the time course of intracranial high-intensity transient signals (HITS) in patients undergoing elective heart valve replacement. METHODS: Thirty-three patients were enrolled in this study. The examination protocol included serial (before and at one, five, 90 and 180 days after surgery) monitoring sessions with transcranial Doppler and detailed neurological examination. Monitoring was performed bilaterally over the middle cerebral arteries for one hour per session using 2 MHz probes. Microembolic signals were recognized according to standard criteria and stored on a computer for later evaluation. RESULTS: HITS prevalence increased from 3% preoperatively to 41% on the first postoperative day and remained unchanged during the postoperative period. No influence of the intensity of anticoagulation or valve type on HITS counts was evident. Unilateral monitoring provided adequate results in 83.9% of cases. CONCLUSIONS: The causative role of the valve implant in the pathogenesis of HITS appears certain, since their prevalence dramatically increases following valve implantation. Valve type, duration of valve implant or intensity of anticoagulation did not influence HITS counts. Bilateral monitoring is warranted for accurate evaluation of HITS counts in this patient group.

Aortic Valve↗
PubMed1996

Autonomic neuropathy in a patient with adrenomyeloneuropathy.

Adrenomyeloneuropathy (AMN) is a clinical subtype of X-linked adrenoleukodystrophy (ALD). In ALD, the accumulation of very long chain fatty acids (VLCFA) in the nervous system, adrenal cortex, and testes due to impaired degradation of VLCFA is thought to be pathogenic. Demonstration of abnormally high levels of saturated VLCFA is diagnostic of ALD. The symptoms of AMN include spastic paraparesis, impaired vibration sense in the distal legs, urinary disturbances, and mild peripheral neuropathy. About further involvement of the autonomic nervous system, no data are available. We report an AMN patient with clinically suspected and electrophysiologically verified autonomic neuropathy, supporting the hypothesis that neuropathy in AMN is at least partially caused by primary axonal degeneration.

Adrenoleukodystrophy↗
PubMed1996

Muscle fatigue, lactate, and pyruvate in mitochondrial myopathy with progressive external ophthalmoplegia.

We studied muscle fatigue and serum lactate and pyruvate levels in 20 patients with mitochondrial myopathy with progressive external ophthalmoplegia (PEO). Fatigue was assessed in the adductor pollicis muscle (AP) using a low-intensity exercise protocol (20 min). Forces (TFs) and relaxation times of ulnar nerve evoked twitches, compound muscle action potentials (CMAPs), and maximal voluntary contractions (MVCs) were monitored. Serum lactate and pyruvate levels were independently measured at rest and after exercise on a bicycle (15 min, 30 W). Most patients showed abnormal fatigue of the AP with a reduction of TFs and MVCs and normal CMAPs. The reduced TFs were significantly correlated with lactate levels at rest (r= - 0.60, P<0.05) and less so with those after exercise (r=- 0.47,P<0.05). Pyruvate levels revealed a similar correlation although they were widely scattered. We conclude that abnormal fatigue in PEO is metabolic, is localized beyond the muscle fiber membrane, and involves the electrome-chanical coupling and the contractile apparatus. Serum lactate levels at rest are good predictors of fatigue in PEO.

Action Potentials↗
PubMed1996

[Delusion of mercury poisoning in multiple sclerosis].

We confirmed the diagnosis of multiple sclerosis in a 54-year-old man. The patient rejected this diagnosis and was completely convinced that all his symptoms resulted from a chronic mercury intoxication. We found evidence that this delusional disorder was an independent illness, and not a "symptomatic psychosis in multiple sclerosis." So far, little notice has been taken in psychiatry of delusions of environmental poisoning, which cause difficulties in applying common criteria of delusion.

Delusions↗