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Biomedical subjects

W Fritz

Publications and source records attributed to W Fritz.

At least 19 recordsLinked to original sources
PubMed1990

Visualization of differential neurofilament phosphorylation in the pre- and postsynaptic axoplasm of the squid giant synapse: an electron spectroscopic study.

When inelastically scattered electrons with an energy loss specific for interaction with phosphorus atoms were used for visualization of sections of squid axons, bead-like domains of elongated proteins, presumably neurofilaments, exhibited distinct phosphorus signals. A marked asymmetry of these phosphorus signals was detectable between the pre- and the postsynaptic cytoskeleton of the giant synapse. Signals were very numerous and intense in the presynaptic terminal, while rare and weak in the postsynaptic axoplasm. The giant axon revealed a delayed appearance of phosphorus signals in its course from the cell bodies in the giant fibre lobe to its exit from the stellate ganglion. Numerous and intense phosphorylation signals were evident only in the peripheral giant axon. Asymmetry in the distribution of phosphorus signals between pre- and postsynaptic axoplasm paralleled differences in Ca(2+)-buffering mechanisms, as shown in a previous study. In the presynaptic terminal patterns of phosphorus signals correlated with precipitates which had formed after intra-axonal injection of calcium. Our observations suggest a role of phosphorylated neurofilaments in binding of calcium in the squid synapse.

Animals↗
PubMed1989

Quantitative measurement of disc space area before and after chemonucleolysis and nucleotomy.

Measurements of the area of the intervertebral disc space were made, over a period of 400 days or more, in 16 patients who underwent chemonucleolysis and 20 patients after nucleotomy. The superimpositioning method of measurement used is based on a determination of fixed points and it has a high level of reproducibility. We have measured areas which differ from volumes in only a single dimension, but which show good correlation compared with measurement of intervertebral disc space heights alone. After both chemonucleolysis and nucleotomy, narrowing of the intervertebral disc space occurs up to the 50th day, after which there is a highly significant difference: the intervertebral disc space height increases after chemonucleolysis, and continues to decrease after nucleotomy. It is concluded that the enzymatic effect of chymopapain on the nucleus pulposus produces a gain in disc substance after chemonucleolysis, whereas nucleotomy is associated with a loss of substance.

Adolescent↗
PubMed1989

Visualization of polyribosomes in the postsynaptic area of the squid giant synapse by electron spectroscopic imaging.

Giant axons from squids (Loligo vulgaris and Loligo pealii) were studied by conventional electron microscopy and by electron spectroscopic imaging: electrons with a characteristic energy loss due to interaction with phosphorus atoms were used to image phosphorus-rich elements such as ribosomes. Patches of granular material were seen in the proximal region of giant axons, especially in the postsynaptic area of the giant synapse, but not on the presynaptic side. They were rare or absent in the more distal part of the axon. With electron spectroscopic imaging the patches emitted strong phosphorus signals, indistinguishable from signals of ribosomes in neuronal perikarya, confirming their identification as RNA-rich elements. In the part of the axon near the perikarya in the giant fibre lobe, the patches consisted of sacs of rough endoplasmic reticulum. It is suggested that patches of rough endoplasmic reticulum are transported to the synaptic region where ribosomes detach from the cisterns and aggregate into polyribosomes.

Animals↗
PubMed1989

[Sudden deafness and the craniocervical transition].

Morphological alterations of the cranio-cervical junction as a basilar impression, a ponticulus posterior, an atlas assimilation, an intervertebral narrowing, and spondylosis deformans were found radiologically. There was no difference to a healthy population. This means there are no correlations between static morphological changes of the craniocervical junction and sudden deafness. However, there was a statistically significant reduced mobility in the upper cervical spine in patients suffering from sudden deafness. Especially very high standard deviations in the atlanto-occipital and the atlanto-dental joint are interpreted as hypermobile as well hypomobile atlas joints. These results indicate a correlation between sudden deafness and functional pathology of the craniocervical junction.

Adult↗
PubMed1989

Transcranial Doppler sonographic identification of a subgroup of patients with normal pressure hydrocephalus with coexistent vascular disease and treatment failure.

We report on transcranial Doppler sonography with carbogen reactivity testing of flow velocity as applied to patients with normal pressure hydrocephalus. A subgroup can be differentiated that shows coexistent cerebrovascular disease. The surgical prognosis in these patients is bad. A flow chart demonstrating the proposed clinical examination is presented.

Adult↗
PubMed1989

Arteriovenous malformation of the posterior ethmoidal artery as an unusual cause of amaurosis fugax. The ophthalmic steal syndrome.

We report the case of a patient with arteriovenous malformation fed by a posterior ethmoidal artery. The pre-operative amaurotic attacks on the diseased eye subsided after removal of the malformation. Doppler sonographic examination of the peripheral ophthalmic artery showed an inversion of the blood flow direction postoperatively. We describe a concept of an ophthalmic steal syndrome treated in this patient by removal of an arteriovenous malformation.

Arteries↗
PubMed1989

[Diagnostic strategy in primary malignant bone tumors in children].

Our experience concerning the diagnostic proceeding for primary malignant bone tumours in children and their often difficult differentiation from osteomyelitis are discussed. A retrospective evaluation of patient records of 66 children showed, that in 53 cases (41 with osteomyelitis, 12 malign tumours) diagnosis was immediately obtained from clinical and radiological results. For five more children osteomyelitis was proven by short term monitoring and paraclinical investigations, while in 8 cases final diagnosis required biopsy. CT was relevant for the evaluation of intraosseous and intramedullary extending tumours and mandatory for therapy planning. Conventional radiography, however, remains the most important method within the diagnostic strategy, but the need for close cooperation of radiologists and clinicians and a synoptic evaluation of clinical results, radiography and anamnestic data must be stressed.

Adolescent↗
PubMed1988

[Doppler sonographic characterization of vessels of the posterior cranial fossa using a suboccipital paramedian approach].

By means of transcranial Doppler sonography we examined the posterior cranial fossa from the suboccipital paramedian region. This enabled us to identify the basilar artery in its entire course, as well as the posterior inferior cerebellar artery. The advantages of this approach are, in particular, the possibilities of examining postoperatively by Doppler sonography after medial surgical approach, as well as the future utilisation the technique within the overall framework of stereometric transcranial Doppler sonography.

Basilar Artery↗
PubMed1988

[Brain death and intraocular pressure].

The article reports on the changing behaviour of the intraocular pressure of 20 patients who had a severe head injury. Eight patients survived; in this group intraocular pressure was always normal. Twelve patients developed brain death, and in contrast to the group of survivors all of them had intraocular hypotension. Papilloedema was never seen in funduscopic examinations; however, we found signs of fundus ischaemia in most patients who had died of brain death.

Adolescent↗
PubMed1988

Hearing loss after microvascular decompression for trigeminal neuralgia.

Of 21 patients examined audiometrically before and after microvascular decompression of the trigeminal nerve, five (23.8%) had postoperative hearing impairment. A middle ear effusion was found in three (14.3%), probably caused by mastoid cell opening. A retrocochlear lesion in the other patients was caused by transferred pressure on the cochlear nuclei or by traction on the nerve. Vascular perfusion problems were also possible but are difficult to document.

Hearing Loss↗
PubMed1986

[Intensive care problems in congenital polycystic lung abnormality].

The development of bilateral tension cysts in a 6-month-old child suffering from inborn honeycomb lung resulted in acute cardiorespiratory insufficiency. First of all, we succeeded in controlling the recurrent rises in intrathoracic pressure by puncturing and chest draining performed by suction and by the Bülau method. The child thus became fit to be operated on. The right lower lobe, and, 7 days later, the left upper lobe, were resected and multiple single cysts excised from both residual lungs. The postoperative course of the disease was not free from complications, but five years of follow-up showed that the child's general development had become normal. Possibilities of treatment of pulmonary insufficiency, a typical symptom of polycystic lung malformation, are discussed, and the necessity for an early operation is emphasised.

Critical Care↗
PubMed1986

[Experiences with preoperative and palliative percutaneous transhepatic cholangio-drainage].

In obstructive jaundice PTCD plays an important role as a preoperative or a palliative therapeutic method inspite of the availability of biliary endoprostheses. This study was carried out to assess complications following PTCD, the effect on liver function (serum parameters) and the relationship between duration of preoperative drainage and postoperative complication rate. The results demonstrate that 11-hole pigtail-catheters are useful for intrahepatic location and 32-hole ringcatheters for extrahepatic location due to reduced dislocation rates. The effect of biliary drainage after 7 rsp. 25 days on liver function was significant (p less than 0.05). As a main complication fever episodes could be observed associated with pathologic bile-/bloodcultures in most cases; other complications were similar to those presented in the literature. A prophylactic antibiotic therapy following PTCD seems to be useful, a preoperative biliary drainage is recommended until serum bilirubin levels become constant or at least for 2 weeks.

Adult↗
PubMed1985

Isolation and characterization of factors from wheat germ that exhibit eukaryotic initiation factor 4B activity and overcome 7-methylguanosine 5'-triphosphate inhibition of polypeptide synthesis.

Three highly purified preparations (preparations I, II-1, and II-2) have been obtained from wheat germ and shown to support in vitro polypeptide synthesis directed by capped or uncapped mRNAs in a eukaryotic initiation factor 4B (eIF-4B)-deficient system. The three preparations differ, however, in polypeptide composition and in the ability to overcome the inhibitory effect of 7-methylguanosine 5'-triphosphate (m7GTP) on in vitro polypeptide synthesis. Preparation I contains two polypeptides (Mr = 80,000 and 28,000), which are present in a 1:1 molar ratio and are associated in a high molecular weight complex. Preparation II-1 contains two major polypeptides (Mr = 220,000 and 26,000) and preparation II-2 also contains two major polypeptides (Mr = 110,000 and 26,000). Preparations II-1 and II-2 are high molecular weight complexes; neither contains detectable amounts of a Mr 80,000 or a Mr 50,000 component. Preparations II-1 and II-2 both overcome m7GTP inhibition, whereas preparation I does not. These findings raise several questions with regard to the identity of eIF-4B and its relationship to cap recognition factors.

Chromatography, Ion Exchange↗
PubMed1984

[Transport of benzo(a)pyrene into animal organs following the feeding of activated sludge from swine manure].

In feeding experiments with pigs and fish (carp and trout) the test animals received quotas of activated sludge of 7.5 and 15% DM (pigs) and 20% (carp) in their mixed feed. In an experiment with trout in an aquarium the quota of activated sludge was increased from 20% to 50%. The benzo(a)pyrene content was ascertained in selected organs of the pigs (kidney, liver, bacon, muscles) and the edible parts of the fish. As a result of this experiment one can say that the feeding of activated sludge from pig manure does not result in an increased benzo(a)pyrene content in the tested organs of the pigs and the edible parts of the fish.

Animal Feed↗