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Biomedical subjects

E Lang

Publications and source records attributed to E Lang.

At least 91 records · Page 5Linked to original sources
PubMed1994

The phylogenetic structure of the genus Acinetobacter.

16S rDNA sequence analysis was performed on the type strains of all validly described Acinetobacter species and five unnamed Acinetobacter strains. The phylogenetic analyses confirm that Acinetobacter is a coherent genus within the gamma subclass of Proteobacteria and that the species are phylogenetically well defined. A. calcoaceticus, A. lwoffii, A. johnsonii and A. haemolyticus form one cluster of closely related species, the pair A. junii and A. baumannii forms a second cluster. A. radioresistens stands phylogenetically isolated. The study reveals that three undescribed strains can be assigned to individually described species, while strains DSM 30009 and DSM 590 may represent two novel Acinetobacter species.

Acinetobacter↗
PubMed1994

Spectroscopic evidence that monoclonal antibodies recognize the dominant conformation of medium-sized synthetic peptides.

Spectroscopic methods have amply documented that small- and medium-sized peptides tend to assume unordered conformations in water. The conformational tendencies, however, manifest in halogenated alcohols, and the preferred secondary structures are apparent from the circular dichroism (CD) spectra. Here we report the results of immobilizing peptide and protein antigens from various mixtures of trifluoroethanol and water during enzyme-linked immunosorbent assays. The increased recognition by the appropriate monoclonal antibodies (mAbs) is correlated with the increase of the alpha helical, beta turn, or beta pleated sheet content of the peptides presented in the different solvent mixtures. Remarkably, the antibody binding can be detected at considerably lower antigen levels if the antigen is immobilized from trifluoroethanol. The antigens we used corresponded to fragments of normal human neurofilaments and tau protein found in the paired helical filaments of Alzheimer's disease, and the nucleoprotein of rabies virus. The conformation of myoglobin is as stable in water as in trifluoroethanol, and therefore acted as a negative control. Indeed, the recognition of myoglobin did not increase upon increasing the trifluoroethanol concentration in the solvent used to apply the antigen to the plate. The possibility of imperfect binding to the plastic carrier or nonspecific binding to irrelevant antibodies is excluded by using control experiments. We offer the first direct evidence that the mAbs recognize the secondary structure of epitopes, and that it is possible to correlate the binding conformation of the epitopes with CD measurements made in trifluoroethanol-water mixtures.

Animals↗
PubMed1994

Tyrosine- versus serine-phosphorylation leads to conformational changes in a synthetic tau peptide.

One of the major immunodominant epitopes of the paired helical filaments (PHF) of Alzheimer's disease is the peptide sequence GAEIVYKSPVVSGD (T3), comprising amino acids 389-402 of the microtubule-associated protein, tau, when it is phosphorylated at the first serine residue. While the corresponding anti-PHF monoclonal antibody recognizes the peptide phosphorylated at either serine, it does not recognize the tyrosine-phosphorylated peptide. Here we describe the effect of serine- versus tyrosine-phosphorylation on the conformation of a synthetic tau peptide. While adding a phosphate to the serine residue has practically no impact on the structure of the non-phosphorylated peptide, phosphorylation of the tyrosine results in considerable conformational changes.

Alzheimer Disease↗
PubMed1994

Efficacy and safety of iopromide for excretory urography.

RATIONALE AND OBJECTIVES: Iopromide is a nonionic monomeric contrast agent. Initial laboratory and clinical data have shown that it is relatively safe. Efficacy for excretory urography has been shown to be good, comparable with other low-osmolality agents. The authors attempted to confirm these impressions in a randomized, double-blind comparison with equivalent doses of ioversol and iopamidol. METHODS: Two hundred adult patients undergoing excretory urography were studied. One hundred received iopromide, 40 received ioversol, and 60 received iopamidol (300 mg I/kg) as an intravenous bolus. Urographic films (obtained 1, 5, 15, and 20 minutes after the bolus, and postvoid) were interpreted by an observer blinded to contrast type. Visualization of renal parenchyma, pelvis and calyces, ureters, and bladder was independently assessed as excellent, good, poor, or nonvisualized. Vital signs were recorded before, 30 to 60 minutes after, and 24 hours after injection. Adverse reactions were sought, physical examinations were performed, and standard hematology and serum chemistry values were measured before and 1 day after injection; a 72-hour serum creatinine level was also measured. RESULTS: Ninety-eight percent of visualization scores were good or excellent; no significant differences among iopromide, iopamidol, and ioversol were found, nor were there any significant differences among groups in vital signs. Only one patient experienced a contrast-related physical examination change (subcutaneous extravasation). No significant changes with regard to hematology or serum chemistry values were observed; there was no contrast-induced nephropathy. Mild adverse reactions were experienced by 10% of patients; there were no significant differences in reaction rates among contrast agents. CONCLUSIONS: Iopromide at a dose of approximately 300 mg I/kg is safe and effective as an excretory urographic agent and is comparable in performance with ioversol and iopamidol.

Adult↗
PubMed1994

The measurement of alcohol dependence and impaired control in community samples.

The concept of the Alcohol Dependence Syndrome has been influential in the field of alcohol studies in the 1980s. The Severity of Alcohol Dependence Questionnaire (SADQ) is one of a generation of alcohol problem scales developed to measure degree of dependence rather than presence or absence of 'alcoholism'. This paper describes the development of a form of the SADQ for community samples of drinkers (SADQ-C) and its relationship to a brief scale designed to measure impaired control over drinking. In a sample of 52 problem drinkers, SADQ and SADQ-C correlated almost perfectly (r = 0.98). In a larger sample of 197 attenders at a controlled drinking clinic, Principal Components Analysis revealed one major factor accounting for 71.7% of the total variance. High internal reliability was indicated with a Cronbach's Alpha of 0.98. Application of this instrument in a random survey of Western Australian households is then described. It was necessary to remove items relating to 'reinstatement of dependence' for this sample. A single major factor was identified by principal components analysis, accounting for 69.1% of the total variance. In both the clinic and the community samples SADQ-C scores correlated highly with Impairment of Control scores. The findings are interpreted as supporting the view that there is a single dimension of alcohol dependence upon which all persons who drink alcohol with any regularity may be located.

Adolescent↗
PubMed1994

Can health/medical informatics be regarded as a separate discipline?

The participants of the panel on education and training in Medical Informatics, concurred that health/medical informatics is today thriving as a separate discipline, despite inevitable uncertainties regarding the future. Conferees discussed the distinctions between physician-built systems and those designed by medical informaticians, focusing on methodology as critical to medical informatics.

Medical Informatics↗
PubMed1993

Quantitative assessment of sudomotor activity by capacitance hygrometry.

A commercial capacitive hygrometer device manufactured for use in technical or chemical laboratory environments has been used for quantitative and dynamic assessment of sweat gland activity in selected skin areas. For this purpose the hygrometer device was supplemented by a chamber attached to the skin for collecting evaporated water and a supply of dry nitrogen gas providing a gas flow through the chamber and through the hygrometer capsule. The accuracy of the technique was proven in pilot experiments in which fixed amounts of water were evaporated. A positive correlation was found between the weight of the water and the water evaporation computed from the hygrometer readings (r = 0.997). The time constant of the device was in the range of 10 s. This time constant appears to be fast enough for recording physiological changes in the sweating rate of human subjects. In experiments on healthy subjects sudomotor reflexes were assessed and compared to vasoconstrictor responses and to thermographically measured temperature changes of the skin during the Valsalva manoeuvre and a painful mechanical stimulus. Direct measurement of water evaporation such as by this technique may provide information on sympathetic reactions which could be utilized in both physiological and pathophysiological states.

Absorption↗
PubMed1993

Public support for the prevention of alcohol-related problems.

Support for a number of strategies and policies for the prevention of alcohol related harm was ascertained as part of a larger survey of public attitudes and behaviours in a representative sample of the Perth metropolitan area. Support for these policies varied, but was generally positive, with young male drinkers the least supportive. The greatest degree of support was found for a variety of training strategies for licensees and barstaff, while a number of restrictive practices, such as reduced trading hours and the banning of the sale of beer in jugs, were less popular. Those who had recently worked in the alcohol trade were less likely than the general population to be supportive of these policies. This effect could not be completely explained by their generally being younger and drinkers. It is concluded that governments generally have a mandate to introduce certain policies and practices into the licensed drinking environment, but that the resistance of the alcohol trade to such measures may need to be overcome if they are to be successfully introduced.

Journal Article↗
PubMed1993

Public perceptions of responsibility and liability in the licensed drinking environment.

This study reports the results of a survey conducted in Perth (Western Australia) to assess public perceptions of the concepts of server responsibility and server liability. Eleven hundred and sixty persons aged 16 and over were asked if they thought licensees and barstaff should be held partly responsible when someone becomes intoxicated on licensed premises, or licensees and barstaff should be partly liable for injuries caused by an intoxicated person after leaving licensed premises. Results indicate that, on average, few people agreed to either proposition, despite an overwhelming majority believing that continuing to serve an intoxicated person increases the risk of an accident. However, when analysed by category of respondent, non-drinkers and persons aged over 30 were significantly more likely to agree with licensees and barstaff being partly responsible for someone becoming intoxicated, and for them to be partly liable in the case of an accident involving an intoxicated customer. The results of this survey indicate the need for education programmes to convince the public that excessive alcohol consumption and the resulting harm is not merely the responsibility of the individuals concerned, but is also the responsibility of those groups and individuals involved in the promotion, marketing and sale of alcohol. We suggest that such education campaigns might best be targeted at those groups where least support was found, young drinkers (18-24 years) and the servers of alcohol.

Journal Article↗
PubMed1993

High risk drinking settings: the association of serving and promotional practices with harmful drinking.

A household survey of 1160 Western Australian adults was used as a basis for exploring drinkers' reports about the settings in which they drank alcohol and their experiences of alcohol related harm. Of the 873 drinkers identified, 7.9% had experienced some form of acute alcohol related harm over the previous 3 months. Violent incidents were the most common of these and drink-driving offences the least. Such harm was significantly more likely among drinkers who variously drank 'heavily', were male, single, under 25 years of age and/or who drank on licensed premises. Regression analyses revealed that even when demographic characteristics of the drinkers were controlled for licensed premises were significantly more likely to be the settings used prior to harm occurring. Bar staff continuing to serve 'obviously intoxicated' customers was the most powerful predictor of harm. Premises which offered discounted drinks or permitted crowding also tended to be those where intoxication was permitted but these variables were not directly associated with an increased risk of harm. These findings lend further weight to the view that prevention efforts should focus on licensed drinking environments and, in particular, the practice of continuing to serve obviously intoxicated customers.

Adolescent↗
PubMed1993

The boundaries of psychiatric rehabilitation.

The authors describe the development of modern psychiatric rehabilitation, from its early association with occupational therapy to its present state as a discipline with an armamentarium of treatment strategies. Psychiatric rehabilitation addresses difficulties in three domains of patients' lives: clinical status, functional status, and quality of life. The authors suggest that the acceptance of rehabilitation as a separate discipline has been slow due to boundary conflicts between these domains and between the disciplines that traditionally represent them. The authors call for a more central role for rehabilitation, which integrates treatment in the three domains and uses group methods to formulate plans and enhance client involvement.

Activities of Daily Living↗
PubMed1993

Median nerve blockade during diagnostic intravenous regional anesthesia as measured by somatosensory evoked potentials.

Intravenous regional anesthesia (IVRA) may be used as a diagnostic method in patients suffering from chronic pain in the forearm or hand to differentiate the origin of pain within the anesthetic area from that above. For this purpose it needs to be proven that all nerve fibers are blocked and that conduction blockade induced by IVRA takes place within the nerve trunks. Therefore the transmission of impulses in a nerve trunk to the central nervous system has been studied. Diagnostic intravenous regional anesthesia (5 mg/kg mepivacaine 1%) of the arm was performed in eight patients for 30 min. Short-latency somatosensory evoked potentials (SSEPs) induced by median nerve stimulation at the wrist were recorded from the scalp at 5-min intervals before, during, and after IVRA. In five patients, sensory nerve action potentials (SNAPs) of the median nerve, at the elbow and axilla, and SSEPs at spinous processus C-7 were recorded simultaneously. During IVRA the function of the nerve fibers which are assumed to mediate pain was tested by the patient's sensation following median nerve stimulation at an intensity which evoked pain before IVRA. During IVRA, peak latencies of the scalp recorded SSEPs (N20) increased progressively and interpeak amplitudes (N20/P25) decreased. After 20 min, SSEPs could no longer be recorded, and median nerve stimulation no longer evoked any sensation at all. After deflation of the cuff, both peak latency (N20) and interpeak amplitude (N20/P25) of SSEPs recovered. The changes in latency and amplitude of SSEPs from the scalp as well as SNAPs and SSEPs from the neck were similar. Because SSEPs, SNAPs, and the pain sensation following median nerve stimulation disappeared during IVRA, it may be concluded that the thick and thin myelinated nerve fibers of the median nerve have been blocked. For diagnostic use, IVRA is superior to peripheral nerve blockade, which has been shown previously to not abolish SSEPs.

Adult↗
PubMed1993

Stereotactic percutaneous lumbar discectomy.

Sixty-nine patients with documented and contained disc herniations underwent percutaneous discectomy. The procedure was carried out with a new stereotactic device mounted on the floor and positioned over the computed tomographic scanner. In each instance, this device provided accurate insertion of the needle and localization of the aspiration probe (Nucleotome) within the appropriate area of the disc. Aspiration of the herniated nucleus pulposus was accomplished in every patient, and no complications were encountered.

Humans↗
PubMed1993

Cloning of several genes coding for retinoic acid nuclear receptors in the mouse embryonal carcinoma cell line PCC7-MZ1.

Mouse embryonal carcinoma cell line PCC7-Mz1 can be induced by retinoic acid (RA) to differentiate into several well defined phenotypes of neuroectodermal origin (Lang, E. et al. (1989) J. Cell. Biol. 109, 2481-2493). Several subclones of the cell line (clonal variants) differ from each other in their developmental potential. To test whether these differences in cellular fate are due to somatic mutations in specific genes of these cells, we have cloned full length cDNAs coding for the alpha 1 and beta 2 isoforms, and partial length cDNAs coding for the alpha 2, beta 1 and beta 3 isoforms of the retinoic acid nuclear receptor (RAR). The cloned cDNAs did not differ in sequence from those of normal mouse cells. Using as probe the beta 2-RAR promoter region from mouse liver, we also checked for restriction fragment length polymorphism in the promoter regions of RA-inducible and RA-resistant cell variants. No alterations in this region of RAR genes was found in the clonal variants tested. The different patterns of derivatives produced by the variants upon exposure to RA therefore cannot be caused by somatic mutations in RAR genes of the tumor cell lines.

Amino Acid Sequence↗