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K Voigt

Publications and source records attributed to K Voigt.

At least 91 records · Page 5Linked to original sources
PubMed1991

[Further possibilities for the application of the digital subtraction technique in neuroradiologic diagnosis].

The article presents, as methods that can be used in addition to digital subtraction angiography, ventriculography, myelography, discography as well as control examinations of shunts and port systems to widen the scope of digital subtraction techniques (DST) in neuroradiological diagnostics. Besides the reduction of amount and concentration of contrast media, more comprehensive and better diagnostic results were achieved for all examination methods with regard to the functional and dynamic aspects, the spatial resolution being of comparable quality.

Anastomosis, Surgical↗
PubMed1991

New device for CT-targeted percutaneous punctures.

A device for computed tomography (CT)-guided percutaneous punctures that is not affixed to the patient and can be used even when the gantry is tilted was developed and tested. In initial patient examinations, the device was accurate within 1.0 mm of the predetermined target point. Experience so far has involved retrobulbar anesthesia and puncture of intervertebral disk space.

Anesthesia, Local↗
PubMed1991

Elevated serum diiodotyrosine (DIT) in severe infections and sepsis: DIT, a possible new marker of leukocyte activity.

Ether link cleavage (ELC) of T4 yielding diiodotyrosine (DIT) has recently been shown in vitro to be the major pathway of T4 metabolism in phagocytosing leukocytes. To evaluate this pathway in vivo and the possible clinical relevance of DIT measurements in diseases with increased leukocyte activity, radioimmunological studies on serum levels of DIT and other thyroid parameters were performed in 125 critically ill patients classified into 3 groups with bacterial infections according to the severity of infection and 1 group without infections. While the pattern of iodothyronine and TSH levels typical for severe nonthyroidal disorders, i.e. decreased total T3 and elevated rT3, normal or decreased total T4 and TSH, and normal free T4, was found in all four groups of intensive care patients studied, elevated serum DIT was observed only in those patients whose clinical course was complicated by severe bacterial infections. Serial measurements revealed a close temporal connection between the infection phase and increased DIT levels. Median values and 16th to 84th percentile ranges (in parentheses) of serum DIT (normal range, 0.02-0.55 nmol/L) were as follows: sepsis, 1.38 (0.32-5.14); severe nonsystemic infections such as peritonitis and abscesses, 3.84 (0.24-17.2); moderate infections such as pneumonia and tracheobronchitis, 0.44 (0.18-1.16); and critical illness without infections, 0.14 (0.08-0.30) nmol/L. These elevations of circulating DIT could neither be correlated with changes in renal function nor attributed to drug effects. The results of the present study do not allow any definitive conclusions to be made about the mechanisms underlying the phenomenon of increased serum DIT levels in infections. Apart from this open question, DIT appears to be a relatively specific serum parameter for the presence and course of severe bacterial inflammations. Its measurement could provide useful clinical information, particularly for monitoring the time course of deep-seated infections.

Bacterial Infections↗
PubMed1991

[Differential diagnosis of lytic lesions of the jaw].

Using typical CT-pictures the different types of jaw cysts are classified, the characteristic findings of the individual cyst types emphasised and the differential diagnosis discussed. High-resolution-CT can be highly informative and of special value in the diagnosis and assessment of expanding and infiltrating lesions of the jaws.

Diagnosis, Differential↗
PubMed1990

Neurokinin-immunoreactivity in human neuroblastomas. Evidence for selective expression of the preprotachykinin (PPT) II gene.

Factors regulating differentiation of the peripheral nervous system (PNS) have been widely studied in neuroblastomas which are tumors of the PNS. Five neuroblastomas were investigated for their content of tachykinin neuropeptides, which arise from two distinct genes which appear differentially expressed in the PNS. Radioimmunoassay and column chromatography revealed large amounts of neurokinin B in three of these tumors and the absence of substance P, neurokinin A, neuropeptide K and neuropeptide gamma from all five tumors. This suggests that neuroblastomas can selectively express the preprotachykinin (PPT) II gene and that they may be valuable for investigating the factors involved in the regulation of these two structurally-related neuropeptide genes.

Chromatography, High Pressure Liquid↗
PubMed1990

Isolation and full structural characterisation of six adrenocorticotropin-like peptides from porcine pituitary gland. Identification of three novel fragments of adrenocorticotropin and of two forms of a novel adrenocorticotropin-like peptide.

A partially purified fraction of extracted porcine pituitary glands which possesses lipolytic and adrenocorticotropic activity has been characterised. It consists of six adrenocorticotropin(ACTH)-like peptides (five of which have not been previously described) which were each purified by sequential reverse-phase (rp) HPLC. Their complete primary structures were determined following amino acid compositional analysis, extensive peptide mapping and partial sequencing. Four of the fragments represent the following ACTH fragments; ACTH(1-31), ACTH(7-34), ACTH(7-36) and ACTH(7-38). By combined analytical rpHPLC and an ACTH radioimmunoassay (with an antiserum exhibiting full cross-reaction with all six ACTH variants isolated here), evidence was obtained from analysis of extracts of whole pituitary that these fragments of ACTH exist in significant amounts relative to intact ACTH(1-39). This suggests that ACTH can undergo more extensive differential proteolytic processing than previously thought. These peptides were found to possess reduced or a complete absence of ACTH-like biological activity. Therefore the biological significance of this processing needs to be resolved. The other two fragments also resembled fragments of ACTH but each possessed the same, single amino acid substitution: a threonine replacing the arginine at the position corresponding to position 8 in the ACTH sequence and had the structures [Thr8]ACTH(1-31) and [Thr8]ACTH(7-31). They possess little ACTH-like biological activity. If these variants are derived from a variant ACTH, this would be a significant finding in view of the site of the amino acid substitution and the highly conserved nature of the ACTH primary structure. The possible physiological and genetic implications are briefly discussed. In this study attempts were also made to identify the DNA coding for the mutant ACTH sequence.

Adrenocorticotropic Hormone↗
PubMed1990

Hormonal responses to exhausting physical exercise: the role of predictability and controllability of the situation.

Psychological conditions which produce sustained activation have been clearly identified. Among these are the predictability and the controllability of the situation. We studied the impact of these psychological variables on hormone secretion (cortisol, ACTH, vasopressin, prolactin, and hGH plasma levels) under a standardized physical load. Sixteen subjects participated in four sessions each, one week apart, with the task of riding a bicycle until exhaustion. During three sessions, all experimental conditions were held identical to ensure the situation was a predictable as possible. During the fourth session, instructions induced a certain level of uncontrollability. Whereas physiological and performance measures did not vary with experience in the task, cortisol, ACTH, and vasopressin responses declined with increasing experience. This emphasizes the importance of the psychological definition of the situation for endocrine stress responses.

Adrenocorticotropic Hormone↗
PubMed1990

Time course of ACTH 4-10 effects on human attention.

Previous studies have demonstrated that the adrenocorticotropic hormone (ACTH) and its 4-10 fragment are potent modulators of attention in humans. In these studies the Nd component ('negative displacement') of the stimulus-evoked brain potential (event-related potential, ERP), which is a neurophysiological indicator of selective attention, proved most sensitive to effects of these peptides. The Nd decreased in amplitude linearly with logarithmically increasing doses of ACTH 4-10 applied. Here we report results complementing these previous findings by establishing a time course of the effects of ACTH 4-10 on human attention. In a double-blind cross-over study, attention performance on a dichotic listening task was tested in 18 healthy volunteers, after having received intravenously either placebo or 1 mg ACTH 4-10. Tests took place 0, 30, 90, 180, 330, 600 min, 24, 48 and 72 h after drug intake and took about 15 min. Each subject was tested on 4 of these occasions, selected according to a random schedule. During task performance ERPs to the different task stimuli were recorded. ERPs were used to determine the Nd (an indicator of controlled processing of stimuli which the subjects selectively attended to) and the mismatch negativity (MMN) reflecting automatic processing of stimulus deviance. ACTH 4-10 diminished the Nd significantly at 30 min after treatment administration. On none of the other occasions significant changes in Nd occurred. MMN was not affected by the peptide. The results indicate a short-term action of ACTH 4-10 on selective attention, which takes about 30 min to develop and does not last longer than 90 min after treatment.

Adrenocorticotropic Hormone↗
PubMed1989

Abnormal origin of the ophthalmic artery from the anterior cerebral artery: neuroradiological and intraoperative findings.

A 7-year old male child with an abnormal ophthalmic artery arising from the A1 segment of the anterior cerebral artery is described. The patient suffered growth inhibition which was thought to be caused by a craniobasal cystic lesion affecting the hypothalamus. Preoperative angiograms revealed no vascular abnormalities. The right ophthalmic artery, however, could not be identified. During resection of a large arachnoid cyst the ophthalmic artery was found to arise from the A1 segment of the anterior cerebral artery. To the best of our knowledge, this exact anomaly has not previously been reported. The clinical, neuroradiological and intraoperative findings are presented.

Arachnoid↗
PubMed1989

[Early detection of environmental chemicals in food by means of specific substance criteria].

In an approach to selecting potential food contaminants by means of specific substance criteria we came up with a list of 68 chemicals. Among them, we found chemicals which are already well known as food contaminants such as polycyclic aromatic hydrocarbons and chloroaromatic compounds. So far, other chemicals have not been mentioned as food contaminants. During a project called "Information System for Environmental Chemicals" we conducted, for these 68 chemicals, an intensive literature search in databases for their occurrence in food. The results are stored in our factual databank named "LEBKON" and are graphically described in profiles. For 44 of the chemicals, we found information for their detection in food or in drinking water. We plan to analyse the remaining substances for which no data have been found in the literature. We placed emphasis on the toxicological properties and the production volume of the substances in question. This approach should represent a contribution to the question of monitoring systems oriented by the consumer and monitoring systems oriented by cause.

Animals↗
PubMed1989

Patterns of endocrine secretion during sepsis.

In septic patients the clinical course of the disease is characterized by high DIT and rT3 serum concentrations as well as a low T3-syndrome. While rT3 is elevated in almost all critically ill patients, the increase in DIT is indicative of severe infection. Prolactin levels are regularly elevated in sepsis although to variable degrees. Catecholamines and vasopressin should be regarded as acute responders. The pattern of cortisol secretion is uncertain. In most situations the secretion appears to be elevated; the circadian rhythm is disturbed.

Adrenocorticotropic Hormone↗
PubMed1989

[Magnetic resonance tomography (1.5 T) of traumatic extracerebral hematomas].

The advantages of magnetic resonance imaging (MRI) in the diagnosis of subacute and chronic traumatic extracerebral hematomas are described. The characteristic changes in signal intensity for hematomas depend on the magnetic properties of hemoglobin and its derivatives, which shorten the relaxation times and decrease the homogeneity of the local magnetic field. MRI is superior in detecting and depicting the extent of small hematomas adjacent to the skull. Changes in signal intensity with time allow rough estimation of the age of a hematoma. Small hemorrhages were often found (missed by CT) that were contralateral to chronic subdural hematomas.

Brain Injuries↗
PubMed1988

Vasopressin but not oxytocin enhances cortical arousal: an integrative hypothesis on behavioral effects of neurohypophyseal hormones.

Behavioral changes after administration of the neurohypophyseal hormones vasopressin and oxytocin can be observed in animal and man. Several groups attempted to specify these changes in terms of memory or attention processing enhancement for vasopressin and amnesic properties for oxytocin. These interpretations, however, were targets for recent criticism. In a double-blind between-subject comparison with male volunteers receiving arginine-vasopressin (AVP), oxytocin or placebo intranasally prior to the experimental session, we tried to develop an alternative hypothesis on the basis of behavioral and EEG measures. At the beginning of the session subjects had to learn a list of 25 unrelated nouns within five trials. Recall was assessed 1 h later. Neither learning nor long-term recall were affected by peptide treatments. In a second vigilance task subjects had to covertly count eight series of tone pips. Averaged auditory evoked potentials to these tones showed the expected habituation during the course of the task within all three groups. Vasopressin-treated subjects, however, displayed significantly higher amplitudes of the vertex potential as compared to the other treatment groups. AVP effects were most prominent with the longest interstimulus interval. No influences on heart rate or blood pressure were found. Results indicate that vasopressin induces an enhancement of stimulus-related phasic cortical arousal, and that in this respect oxytocin has no effect.

Adult↗
PubMed1988

Fluocortolone: pharmacokinetics and effect on ACTH and cortisol secretion during daily and alternate-day administration.

The pharmacokinetics of fluocortolone and its effect on the circadian rhythm of plasma cortisol and ACTH have been studied during different schedules of oral administration. Groups of 6 healthy male adults were given a single daily dose of fluocortolone 5, 10 and 20 mg, and another group received 20 mg every second day. Administration to all groups was continued for 8 days. Pharmacokinetic parameters of fluocortolone (half lives of absorption-t1/2a and elimination t1/2e, volume of distribution V and oral clearance (CL/f) were independent of the duration of treatment and dose. Areas under the plasma level curves, AUC and Cmax values increased in proportion to the dose, indicating dose linearity of fluocortolone pharmacokinetics. A normal morning cortisol peak occurred during all treatment schedules, which indicates that circadian cortisol secretion was not seriously affected by the glucocorticoid treatment. On the other hand, when the level of circulating fluocortolone was high the 12.00 a.m. and 4.00 p.m. cortisol levels were diminished compared to the pre and posttreatment values. There was no definite correlation between the ACTH and cortisol levels, either on treatment or on control days. ACTH levels were suppressed by daily treatment with the 20 mg dose. Thus, even during administration of a high dose of a glucocorticoid, the circadian secretion of cortisol can be preserved if the treatment is adjusted according to the half-life of the drug.

Administration, Oral↗
PubMed1988

[Digital subtraction discography].

Conventional cervical discography was carried out in 25 patients during the period of one year. At the same time, we employed the well known principle of digital subtraction. The results of DSD have been compared with conventional discography. In every case more informative images were obtained despite the use of lower amounts of contrast. The distribution pattern of the reduced amounts of contrast in the disc provides valuable information. In the shoulder region, great improvement in picture quality is possible. For these reasons, the use of digital subtraction for discography is justified.

Humans↗
PubMed1988

[Radiculography using the digital subtraction technic].

In patients with symptomatic lumbar disc disease, lumbar myelography was performed in combination with the digital subtraction technique. Contrast medium was injected during the digital subtraction procedure, and the following part of the examination was treated conventionally. In all patients the subtracted images were superior for documentation purposes and also for evaluation of the upper lumbar spine. If the contrast medium was injected epidurally, the artifact could be suppressed by the selection of a suitable mask.

Humans↗