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Biomedical subjects

M Hauser

Publications and source records attributed to M Hauser.

At least 145 records · Page 8Linked to original sources
PubMedDate not supplied

High resolution CT scan of temporal bone fractures: association of facial nerve paralysis with temporal bone fractures.

This radiologic study analyzed high resolution computed tomographic (CT) scans of 22 patients with temporal bone fractures. There were 19 males and three females. Fifteen of 22 had clinical evidence of facial nerve injury ranging from mild paresis to complete paralysis. The high resolution CT scan analysis identified a characteristic fracture of the temporal bone in every patient with facial nerve injury. A high percentage of these fractures (68%) could be classified as mixed and did not fall into a longitudinal or transverse fracture category. The characteristic fracture extends from the petrotympanic fissure at the glenoid fossa to the anterior inferior aspect of the medial bony external auditory canal. It resumes at the superior aspect of the external auditory canal (scutum) extending laterally along the external canal wall. If the vector force of the fracture is projected medially, it will cross the facial nerve in its horizontal portion. Often, the evaluation of trauma patients with routine CT scans for central nervous system (CNS) (brain) evaluation is inadequate for evaluation of temporal bone fractures. A high resolution CT scan should be performed when clinical criteria warrant its use. It is recognized that the incidence of facial nerve injury may be higher in this select population.

Adolescent↗
PubMedDate not supplied

Innominate artery enlargement in congenital arteriovenous fistula with subsequent tracheal compression and stridor.

To demonstrate that airway obstruction may be the first manifestation of a congenital fistula, a female newborn is reported who presented with increasing stridor during her first 23 months of life. Magnetic resonance imaging and Doppler echocardiography revealed an enlarged innominate artery with turbulent flow. Angiography demonstrated an arteriovenous fistula between the right subclavian artery and right subclavian vein and an abnormal origin of the right internal thoracic artery. Bronchoscopy showed a pulsating compression of the middle section of the trachea. Closure and division of the fistula and aortotruncopexy were performed. The stridor disappeared, and there was marked relief of the tracheal obstruction, confirmed by bronchoscopy. It is concluded that, a search for enlarged vessels is necessary in cases of airway obstruction.

Airway Obstruction↗
PubMedDate not supplied

Imaging diagnosis of sclerosing peritonitis and relation of radiologic signs to the extent of the disease.

BACKGROUND: Sclerosing peritonitis (SP) is a serious complication of chronic ambulatory peritoneal dialysis (CAPD) that is characterized by thickened peritoneal membranes, leading to impaired ultrafiltration and intestinal obstruction. The aim of this study was to analyze the radiographic signs of SP in symptomatic patients and to compare them with the histological severity of the disease. METHODS: In 14 patients with symptoms of intestinal obstruction related to SP, plain films of the abdomen, upper GI follow-through examinations, ultrasonography, and computed tomography were evaluated retrospectively. Imaging findings such as bowel motility, bowel wall and peritoneal thickness, and the presence of intraperitoneal fluid collections were correlated to the histological degree of the fibrosis. RESULTS: Signs of intestinal obstruction and disturbed motility were present in all cases. In addition, patients with histologically severe SP had loculated fluid collections, thickening of the bowel wall and/or peritoneum, peritoneal calcifications, and thickened peritoneal membranes, and suffered more often from postoperative complications. CONCLUSION: The detection of characteristic radiographic signs in CAPD patients presenting with symptoms of intestinal obstruction may suggest the presence of severe SP and should lead to cautious surgical interventions.

Adult↗
PubMedDate not supplied

The Glu-modification of alpha-tubulin in the feeding apparatus of the primitive flagellate Entosiphon sulcatum is only apparent after detergent treatment.

Using specific monoclonal antibodies, we investigated the distribution of post-translational modified Tyr- and Glu-tubulins during interphase of the primitive flagellate Entosiphon sulcatum. Immunofluorescence studies of simultaneously permeabilized and fixed cells revealed that microtubular structures comprising Ca(2+)-labile subpellicular and flagellar MTs and Ca(2+)-stable MTs in the siphon complex (feeding organelle) reacted surprisingly unorthodox with antibodies against Tyr- and Glu-tubulin: Unexpectedly, the siphon complex consisting of Ca(2+)-stable MTs appeared exclusively Tyr-positive, whereas the Ca(2+)-labile subpellicular and flagellar MTs reacted with the Glu- as well as with the Tyr-antibody. That the siphon MTs were indeed Ca(2+)-stable and all other MTs had become solubilized, was verified by EM-observation. This surprising result contrasting considerably with the permanent nature of the siphon complex, was reconsidered after preceding lysis and extraction procedures. Depending on the type of detergent used and on extraction times applied, the MTs of the siphon complex now always showed also Glu-positivity, indicating the presence of detyrosinated alpha-tubulin as a biochemical marker of stabilized MTs. Since saponin, irrespective of subsequent extraction times, always produced a Glu-positive reaction and ultrastructural analysis never gave compelling evidence for a drastic MAP-removal, we conclude that the Glu-epitope became freely accessible due to conformational changes in the tubulin polymeres.

Animals↗
PubMedDate not supplied

Multiplicity and regulation of genes encoding peptide transporters in Saccharomyces cerevisiae.

The model eukaryote Saccharomyces cerevisiae has two distinct peptide transport mechanisms, one for di-/tripeptides (the PTR system) and another for tetra-/pentapeptides (the OPT system). The PTR system consists of three genes, PTR1, PTR2 and PTR3. The transporter (Ptr2p), encoded by the gene PTR2, is a 12 transmembrane domain (TMD) integral membrane protein that translocates di-/tripeptides. Homologues to Ptr2p have been identified in virtually all organisms examined to date and comprise the PTR family of transport proteins. In S. cerevisiae, the expression of PTR2 is highly regulated at the cellular level by complex interactions of many genes, including PTR1, PTR3, CUP9 and SSY1. Oligopeptides, consisting of four to five amino acids, are transported by the 12-14 TMD integral membrane protein Opt1p. Unlike Ptr2p, distribution of this protein appears limited to fungi and plants, and there appears to be three paralogues in S. cerevisiae. This transporter has an affinity for enkephalin, an endogenous mammalian pentapeptide, as well as for glutathione. Although it is known that OPT1 is normally expressed only during sporulation, to date little is known about the genes and proteins involved in the regulation of OPT1 expression.

Amino Acid Sequence↗