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Biomedical subjects

A Ernst

Publications and source records attributed to A Ernst.

At least 127 records · Page 7Linked to original sources
PubMed1989

Galvanic testing in neuro-otological diagnostics.

From 1980 to 1986, a total of 436 patients were investigated by galvanic testing. Pathological findings resulted in 45 (out of 54) patients with a suspect tumour of the cerebellopontine angle (CPA), 7 (out of 7) patients with a Herpes zoster infection, 25 (out of 32) patients with an isolated, unilateral loss of vestibular function, 4 (out of 14) patients with head injuries. No pathological results of galvanic testing were found in patients with sudden deafness, Meniere's disease, vertebrobasilar or cerebrovascular insufficiency, etc.

Diagnosis, Differential↗
PubMed1988

Identification and nucleotide sequence of the class E tet regulatory elements and operator and inducer binding of the encoded purified Tet repressor.

The regulatory region and repressor (tetRE) gene from the class E tetracycline resistance determinant previously isolated from Enterobacteriaceae have been identified and completely sequenced. The regulatory region is located between the resistance gene and the tetR gene which have opposite polarity. The tetR gene encodes a protein consisting of 211 amino acids with a calculated molecular weight of 23.6 kDa. Cloning of the tetR gene under transcriptional control of the lambda PL promoter leads to overexpression of a polypeptide with an apparent molecular weight of 26 kDa. The purified protein binds sequence specifically to DNA fragments containing putative tet operators. This property is lost in the presence of tetracycline. The relationship of the tetRE sequence to four known tetracycline resistance determinants is discussed.

Amino Acid Sequence↗
PubMed1988

Dazoxiben-induced changes in the thromboxane/prostacyclin balance in the lateral cochlear wall of the guinea pig.

Dazoxiben, a thromboxane synthetase inhibitor, was infused i.v. in a first group of guinea pigs. Saline was given to a second group of animals as controls. Subsequently, the lateral cochlear walls of each animal were prepared and analyzed for thromboxane (TXA) and prostacyclin (PGI) using radioimmunoassay. These studies showed that dazoxiben crosses the blood-labyrinth barrier and shifts the TXA2/PGI2 balance in favor of the latter. The effects demonstrated are discussed with respect to the relevance of prostanoids in cochlear physiology.

6-Ketoprostaglandin F1 alpha↗
PubMed1988

Occult carotid artery injury related to automobile seat belts.

A 24-year-old woman had a clinically occult injury of the carotid artery from the shoulder seat belt restraint in a motor vehicle accident. Acute thromboembolism and hemiplegia occurred two hours after her admission to the emergency department. There were contusions of the neck and chest (seat belt sign) but no associated injuries of the cervical spine, mandible, larynx, or brachial plexus. The diagnosis was made by carotid arteriography after the occurrence of thromboembolism. Early clinical suspicion, diagnosis, and surgical repair of the artery are necessary to prevent delayed or recurrent thromboembolism and stroke. Carotid artery and duodenal injuries in this patient were related to improperly fitting seat belts. The current useful preventive measures are adjustment of seat belts to individual body habitus and the regular use of snugly adjusted belts.

Adult↗
PubMed1988

Purification and characterization of DSIP-like material from ovine pineal glands: possible peptide-protein interaction.

The nonapeptide delta-sleep-inducing peptide (DSIP) has been isolated from venous blood of rabbits induced to sleep. Numerous reports have described sleep as well as extra-sleep effects. Radiochemical and immunochemical data suggest a relationship of DSIP with the pineal gland supported by interactions of this peptide with pineal functions such as the serotonin N-acetyltransferase activity. In order to demonstrate the natural occurrence of DSIP-like material associated with high Mr proteins in the ovine pineal, organs were water-extracted and fractionated by ultrafiltration and gel filtration. Radioimmunoassay (RIA) for DSIP-like fragments of the fractions revealed considerable amounts of pineal DSIP-like immunoreactivity (DSIP-LI) apparently existing in small as well as large molecular forms. Acidification of large DSIP-LI forms resulted in the elution from Sephadex G-50 of Mr less than or equal to 1,000 DSIP-like material. This free DSIP-LI form coeluted with the synthetic DSIP nonapeptide from microBondapak C18 on high-performance liquid chromatography. The results, therefore, appear to indicate the presence of a (biospecific) noncovalent intermolecular interaction of DSIP (1-9) with proteins (Mr greater than or equal to 10,000) of the ovine pineal gland.

Animals↗
PubMed1987

Comparison of DSIP- (delta sleep-inducing peptide) and P-DSIP-like (phosphorylated) immunoreactivity in cerebrospinal fluid of patients with senile dementia of Alzheimer type, multi-infarct syndrome, communicating hydrocephalus and Parkinson's disease.

The concentrations of delta sleep-inducing peptide (DSIP)-like (DSIP-LI) and P-DSIP-like (phosphorylated, Ser7) immunoreactivity (P-DSIP-LI) were measured by specific radioimmunoassay in the cerebrospinal fluid (CSF) of patients with senile dementia of the Alzheimer type [SDAT, subdivided into early (S1), middle (S2) and late dementia (S3)], multi-infarct dementia (MD), Parkinson's disease (PD), vascular disease (VD) and communicating hydrocephalus (H), as well as in control patients (C1, C2). Mean DSIP-LI and P-DSIP-LI concentrations were found to be significantly higher in the elderly control group (C1, mean age 83 +/- 5 years) than in the middle-aged control group (C2, mean age 40 +/- 16 years). DSIP-LI and P-DSIP-LI were positively correlated with age in both control groups. Significant decreases of DSIP-LI compared with age-matched controls (C1) were observed for S2, S3, MD, PD, VD and H. In contrast, no significant differences corresponding to pathology were found for P-DSIP-LI.

Adult↗
PubMed1986

Systolic direction of right ventricular contrast trajectories in the detection of ventricular septal defect with left-to-right shunt.

Abnormal systolic direction of contrast flow toward the transducer within the right ventricle was demonstrated on M-mode echocardiograms in patients with ventricular septal defect (VSD) and left-to-right shunt. The usefulness of this new technique was tested in 30 patients with VSD proved at catheterization and in 300 control subjects. In all subjects, 2-dimensional (2-D) visualization of the defect, 2-D negative contrast effect and M-mode demonstration of positive contrast within the left ventricular (LV) cavity were also performed. Sensitivity and specificity for each technique and each hemodynamic subgroup of patients were determined and compared. A sensitivity of 100% for the diagnosis of VSD by anterior right ventricular (RV) systolic direction of contrast trajectories was achieved in 20 patients with relatively small VSDs and mild to moderate elevation of RV pressure (RV-LV pressure ratio 60%) and mean pulmonary to systemic blood flow ratio of 1.7. Sensitivities of 2-D echocardiography, 2-D negative contrast technique and positive LV contrast appearance on M-mode echocardiography were 63%, 71% and 53%, respectively. Sensitivity of 100% for systolic anterior direction of contrast trajectories was also calculated in 6 patients with RV-LV pressure ratios from 61 to 80% and mean pulmonary to systemic blood flow ratio of 2.7. Sensitivities of 2-D echocardiography, 2-D negative contrast technique and positive contrast appearance in the LV cavity by M-mode echocardiography were 75%, 60% and 86%, respectively. In 4 patients with systemic or nearly systemic RV pressure, sensitivity of systolic anterior direction of RV contrast trajectories decreased drastically, to only 67%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1984

Sleep disturbances in a case of brain-stem lesions; pharmacological study.

A pharmacological study was carried out of a case of severe insomnia following brain-stem lesions; several polygraphic controls were used. Initially total duration of sleep was brief (less than 4 h) with a high REM/NREM ratio and a short paradoxical sleep (PS) latency. In addition, periodic breathing and tremor were observed. Slow injection of delta-sleep-inducing peptide (DSIP) improved sleep both quantitatively and qualitatively, although PS latency remained short. These effects were reversible. The effects of 5-HTP + benzerazide, of L-DOPA + benzerazide (Modopar) and of clonazepam (Rivotril) were compared.

Brain Stem↗
PubMed1984

The influence of various housing conditions on the ocular fundus in Wistar rats.

Examinations of ocular fundi were performed on male Wistar rats which were housed for 2 years individually or in groups of 3, 5 or 10 animals per cage. Photographs were taken to make the data objective and provide a permanent record. The results indicated no differences between the various groups, although there were marked differences between individual rats.

Animals↗
PubMed1983

Wheel-running of rats in combination with a simple self-stimulation procedure.

LONG EVANS hooded rats with chronically implanted electrodes in the Area hypothalamica lateralis (AHL, group 1), the Nucleus linearis rostralis (LR, group 2) and the Nucleus centralis superior (CES, group 3) were offered the possibility to spontaneously perform wheel-running for one hour per session. The number of wheel revolutions per ten minutes and per hour were counted automatically. The rats were connected with a square wave generator by a smooth flexible cable and received stimulus series (50 imp./s; 0.5 ms imp. duration; 0.5 s series duration; 0-3 V intensity) triggered by each complete revolution of the wheel. The sessions took always place at the same time of the day and under the same experimental conditions -- except the change of stimulus intensity. The results with 0 V served as controls. The method has the following advantages: 1. Self-stimulation is induced spontaneously in the first stimulation session. 2. Negative emotional effects can be quantified by the decrease of the wheelrunning activity. -- AHL stimulation caused an increase in the wheel-running activity amounting to 300-350% with a maximum at 3 V. LR stimulation brought about an ambivalent effect with increase to 200% at 1-2 V and decrease to 56% at 3 V. During CES stimulation an increase to 166-240% with its maximum at 2 V was observed. Stimulation with the same parameters did not evoked locomotion in an open field situation.

Animals↗