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Biomedical subjects

A Michel

Publications and source records attributed to A Michel.

At least 37 records · Page 2Linked to original sources

Genetic identification of Saccharomyces bayanus var. uvarum, a cider-fermenting yeast.

Twenty-one Saccharomyces strains isolated from a cider process were analysed in terms of karyotypes, Y' S. cerevisiae sequence occurrence, rDNA structure and cross-fertility with species tester strains. A strong predominance of S. bayanus var. uvarum G. Naumov was found (18 strains vs. three S. cerevisiae). Among the S. bayanus var. uvarum, only three strains proved to contain species-specific Y' S. cerevisiae sequences.

Beverages↗

KUB3 amplification and overexpression in human gliomas.

Gene amplification is known to occur frequently in human glioma. Recently we reported cloning of a novel gene termed glioma-amplified sequence 16 (GAS16) by microdissection-mediated cDNA capture. In this article, we demonstrate that GAS16 results from an alternative splicing process of the Ku70 binding protein 3 (KUB3) that is essential for DNA double-strand break repair. The alternative splice product was found in glioblastoma and in normal fetal brain. We determined the amplification frequency of KUB3 in glioma with different grading. We analyzed a total of 102 glioma primary tumors and found KUB3 to be amplified in 12/82 (14%) glioblastomas, 4/13 anaplastic astrocytomas (30%), and 2/4 astrocytomas, but in none of three pilocytic astrocytomas. Northern blot analysis of glioblastoma shows a strong correlation between KUB3 amplification and overexpression. Amplification of KUB3 appears to be independent of other genetic changes frequently associated with the development of gliomas, including EGFR amplification, LOH of TP53, and LOH of chromosome 10. The KUB3 amplification and overexpression may interfere with the function of KUB3 in the DNA-PK complex involved in the maintenance of genome stability and reduction of mutation frequency.

Alternative Splicing↗

[Is prolonged ambulatory physical therapy after anterior cruciate ligament-plasty indicated? Comparison of costs and benefits].

Thirty-five patients were prospectively examined on average 5.9 and 11.1 months after reconstruction of the anterior cruciate ligament. Eighteen patients were treated postoperatively with a regular physiotherapy (PT) program 2-3 times per week for 30 min, 17 patients with a special, extended, and supervised rehabilitation program 3-5 times per week for 2.5 h. Criteria for exclusion from this study were previous operation or fractures of the affected knee. The bases for the evaluation of the clinical results were the clinical examination, the Lysholm and Tegner scores, KT 1000, angular reproducibility according to Barrett (proprioception), and the figure-of-eight hop test. It appeared that patients treated with extended ambulatory physiotherapy (EAP) gained a significantly higher degree of functionality in the Lysholm score after 5.9 months (p < 0.02) and the Tegner score after 11.1 months (p < 0.05) than patients treated with regular physiotherapy. Patients treated with EAP also displayed better results in the proprioceptive capability test with an angular deviation of 5.8 degrees after 5.9 months compared to 11 degrees in patients receiving regular PT. After 11.1 months, there were no differences in proprioceptive capability between the two groups. Although the EAP patients were faster in the figure-of-eight hop test (0.39 s difference compared to 0.58 s in the PT patients), the results were not statistically significant. In KT 1000 ventral tibial instability was on average 21% lower in the PT patients than in the EAP patients. After 11.1 months, both groups exhibited the same median value of 3 mm. Furthermore, EAP patients were able to return to work after 36.7 days on average, a 35% shorter period than in the case of PT patients (55 days), also of statistical significance (p < 0.02). To conclude, the primarily higher costs of this intensive rehabilitation program are justified by the better functional outcome linked with an earlier return to work.

Adult↗

Imidazo[1,2-a]quinoxalines: synthesis and cyclic nucleotide phosphodiesterase inhibitory activity.

A group of imidazo[1,2-a]quinoxalines have been synthesised from quinoxaline by condensation of an appropriate haloester or intramolecular cyclisation of a keto moiety on an intracyclic nitrogen atom. The reactivity of the heterocycle was explored through diverse reactions such as electrophilic substitution, lithiation and halogen-metal exchange to give access to a new series of derivatives. Confirmation of their structure was mainly performed by NMR, after careful assignment of the signals in comparison to previous attributions made on the parent imidazo[1,2-a]quinoxaline and discussion of available data in the literature. The cyclic nucleotide phosphodiesterase inhibitor activity of some of these derivatives has been assessed on isoenzymes type III and type lV. Compound 15, 4-(methylamino)imidazo[1,2-a]quinoxaline-2-carbonitrile, exhibited potent relaxant activity on smooth muscle, with a potency similar to the one measured with SCA 40, its structural analogue in the imidazo[1,2-a]pyrazine series.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗

Stable expression of human 5alpha-reductase type II in COS1 cells due to chromosomal gene integration: a novel tool for inhibitor identification.

Inhibitors of human 5alpha-reductase type II are promising drug candidates for the treatment of benign prostatic hyperplasia which is associated with high prostatic DHT levels. In this study we describe the evaluation of potential inhibitors in a new cell assay. First a plasmid (pRcCMV-5alphaII) for the expression of human 5alpha-reductase type II was constructed by the use of the vector pRcCMV and transfected into the African green monkey fibroblast-like cell line COS1. By selection with G418 sulfate, ten COS1 single cell clones were obtained of which three stably exhibited high 5alpha-reductase activity. One single cell clone (COS1-5alphaIIST) was selected for further investigations. By Southern blot analysis, fluorescence in situ hybridization (FISH) and comparative PCR experiments it turned out that the expression plasmid pRcCMV-5alphaII has been integrated into the chromosome, resulting in a long-term stable expression of the foreign 5alpha-reductase gene. The newly established cell line was used for testing novel compounds on their inhibitory effect on human 5alpha-reductase type II. Using this whole cell assay, inhibitors with IC(50) values in the nanomolar range could be identified.

Androstenedione↗

The spectrum of vascular lesions in the mammary skin, including angiosarcoma, after breast conservation treatment for breast cancer.

BACKGROUND: With the general acceptance of lumpectomy, axillary staging, and radiotherapy as local treatment for infiltrating breast cancer, an appreciation is evolving for the spectrum of vascular lesions that occur in the mammary skin after this treatment. Most of these lesions develop within the prior radiation field after breast conservation treatment. STUDY DESIGN: A retrospective chart and slide review was conducted, consisting of five patients with cutaneous vascular lesions after breast conservation treatment for infiltrating breast cancer. RESULTS: The latent time interval from definitive treatment of breast cancer to the clinical recognition of vascular lesions ranged from 5 to 11 years. Two patients did not have either arm or breast edema, two patients had breast edema, and the fifth patient had arm edema. Lesions arising in the irradiated mammary skin included extensive lymphangiectasia (one), atypical vascular lesions (two), and cutaneous angiosarcoma (four). CONCLUSIONS: Atypical vascular lesions at the skin margins of mastectomy may be predictive of recurrence after resection of angiosarcoma. Excision of skin from the entire radiation field may be necessary to secure local control of the chest wall in patients with cutaneous angiosarcoma after therapeutic breast radiotherapy.

Aged↗

Evaluation of the suitability of a patient data management system for ICUs on a general ward.

The development of the ICUData patient data management system (PDMS) for intensive care units (ICU), by IMESO GmbH, Hüttenberg, Germany, was based on the assumption that processes and therapies at ICU are the most complex with the highest data density compared with those in other wards. Based on experience with the system and on a survey conducted among users at our pain clinic, we evaluated whether the concept of the present software architecture, which sufficiently reproduces processes and data at an ICU, is suitable as a PDMS for general wards. The highly modular and client-centric approach of the PDMS is founded on a message-based communications architecture (HL7). In the beginning of the year 2000, the system was implemented at the pain management clinic (12 beds) of our hospital. To assess its user friendliness, we conducted a survey of medical staff (n=14). From April 1st 2000 to August 31st 2000, all clinical and administrative data of 658 patients at the pain management clinic were recorded with the PDMS. From the start, all users had access to data and information of other connected data management systems of the hospital (e.g. patient administrative data, patient clinical data). Staff members found the system mostly useful, clearly presented, practical, and easy to learn and use. Users were relatively satisfied with stability and performance of the program but mentioned having only limited knowledge of the program's features. The need for external support during a computer crash was rated negatively. Despite the need for further usage training and improved program performance, the software architecture described seems to be a promising starting point for the construction of a PDMS for general wards.

Attitude of Health Personnel↗

PHF3 expression is frequently reduced in glioma.

Glioblastoma is the most frequent brain tumor and accounts for approximately 50--60% of all astrocytic tumors. Many chromosome alterations have been described in glioblastoma, but only for a few alterations were the genes identified and linked to genetic pathways in glioblastoma development. To contribute to the identification of novel genes involved in glioblastoma development we used a combined immunological and molecular screening approach. Here we report the identification and expression analysis of a novel gene from human chromosome 6q12 that is considered to be the third member of a family of PHD finger containing genes and is termed PHF3. PHF3 is ubiquitously expressed in normal tissues including brain, but its expression is significantly reduced or lost in glioblastoma, glioblastoma cell lines, anaplastic astrocytomas and astrocytomas. The PHF3 protein sequence contains several protein motifs frequently found in transcription factors. One of those motifs is a PHD finger, also termed LAP motif and known to bind large portions of DNA. Another region of the protein revealed a high homology to the transcription factor TFIIS, especially to a region that is necessary for the Polymerase II binding properties of TFIIS. Combining these results, PHF3 is a novel member of a large class of regulatory proteins containing a LAP motif, and loss of its expression in glioblastoma may contribute to glioma development.

Adult↗

A psycho-endocrinological overview of transsexualism.

The technical possibility of surgical sex change has opened up a debate concerning the legitimacy and utility of carrying out such an intervention at the request of the transsexual. Diagnostic, psychological, medical and ethical arguments have been brought forth, both for and against. Nonetheless, anatomical transformation by surgical means has currently become a practice as the frequency of serious gender identity disorders is constantly progressing. After a brief introduction, the present paper will consider typological, aetiological and epidemiological aspects of transsexualism. Treatment of the sex change applicant is then defined and discussed in terms of psychological, psychiatric, endocrinological and surgical aspects. Finally, the question of post-operation follow-up will be examined.

Endocrinology↗

Tracing movement of African buffalo in southern Africa.

Genetic characterisation of two pathogens, namely foot and mouth disease (FMD) virus and Mycobacterium bovis, isolated from African buffalo (Syncerus caffer) in southern Africa was used to determine the origin of buffalo in situations where the source of infection was obscure. By determining the phylogenetic relatedness of various FMD virus isolates using partial sequencing of the main antigenic determinant, VP1, the origin of buffalo moved illegally to the non-endemic region of South Africa was traced to the Kruger National Park (KNP) where FMD is endemic in the buffalo population. Comparative analysis of the 'genetic fingerprints' of bovine tuberculosis isolates from buffalo and cattle has aided in tracing the original source of infection of buffalo populations in the KNP. Furthermore, these analyses have assisted in tracing the origin of infected animals that have been moved to other parts of South Africa.

Africa, Southern↗

Influence of the method of data collection on the documentation of blood-pressure readings with an Anesthesia Information Management System (AIMS).

The influence of methods for record keeping on the documentation of vital signs was assessed for the Anesthesia Information Management System (AIMS) NarkoData. We compared manually entered blood-pressure readings with automatically collected data. These data were stored in a data-base and subsequently evaluated and analyzed. The data sets were split into two groups, "manual" and "automatic". We evaluated the effect of automatic data collection on the incidence of corrected data, data validity and data variation. Blood-pressure readings of 37,726 data sets were analyzed. We could assess that the method of documentation did influence the data quality. It could not be assessed whether the incorrectness of data during automatic data gathering was caused by artefacts or by the anesthesiologist.

Anesthesiology↗

The epidemiology of tuberculosis in free-ranging African buffalo (Syncerus caffer) in the Kruger National Park, South Africa.

The presence of bovine tuberculosis (Mycobacterium bovis) in the Kruger National Park (KNP) was determined for the first time in 1990. It was diagnosed in an African buffalo (Syncerus caffer) bull, which was found recumbent and in an emaciated and moribund state near the south-western boundary fence. This prompted an investigation into the bovine tuberculosis (BTB) status of the KNP, with emphasis on its epidemiological determinants and risk factors. This report documents the findings of surveys that were conducted from 1990 to 1996. It was found that BTB had entered the KNP ecosystem relatively recently (+/- 1960), and has found favourable circumstances for survival and propagation in a fully susceptible and immunologically naive buffalo population. Indications are that it entered the KNP from across the southern river boundary, where the presence of infected domestic cattle herds had been documented. From there the infection spread through the southern buffalo population and is currently spreading in a northward direction. It was estimated that this northward spread took place at a rate of about 6 km per year; the prospect being that, if this rate of spread is maintained, the entire KNP may be affected in less than 30 years from now. Spillover from buffalo had already occurred in species such as chacma baboon (Papio ursinus), lion (Panthera leo), cheetah (Acinonyx jubatus), kudu (Tragelaphus strepsiceros) and leopard (Panthera pardus). Although there is no indication yet that these species act as maintenance hosts, the possibility is raised that these, or an as yet overlooked species, might assume such a role in future. In the KNP, BTB manifests itself as a chronic and predominantly subclinical disease in buffalo. It may take years for clinical signs to develop, and then only at a terminal stage, when emaciation is a constant feature. It is suspected that the time from infection to death is variable and dependent on the animal's immune response, which can be weakened by such factors as stress, old age or droughts. It was found that, in the interim, buffalo have a normal reproductive life. On necropsy, buffalo show almost exclusively lung and upper respiratory tract involvement, pointing to an aerogenous mode of transmission. Histologically, little sign of encapsulation of lesions was detected, which suggests that they are exceptionally susceptible to BTB and that most lesions are open and infectious and progressive, leading ultimately to death of the individual. Evidence also indicates that BTB is progressive within the herd context (92% being the highest prevalence rate thus far determined in a buffalo herd) as well as progressive within the KNP buffalo population (the implication being that virtually all buffalo herds in the KNP will eventually be infected). Preliminary data suggest a positive correlation between disease prevalence and mortality, with potential mortality reaching up to 10% in buffalo herds having BTB prevalence rates of 50 % and higher. Only the future will tell what the effect of the disease on the population dynamics of buffalo will be.

Animals↗

Permanent cerebral hypoperfusion: 'preconditioning-like' effects on rat energy metabolism towards acute systemic hypotension.

Chronic cerebrovascular disorders are often complicated by additional temporary ischaemic insults, resulting in substantial deterioration of brain energy metabolism. In the present study, chronic limitations of oxygen supply were induced in Wistar rats by 2 weeks of permanent bilateral common carotid artery occlusion (2-vo) to initiate a 'preconditioning-like' effect that protects rat brain energy metabolism against further acute systemic hypotension (15 min). Haemodynamic parameters, arterial blood gases and body temperature were monitored. Energy metabolites were determined in rat parietotemporal cerebral cortex: adenosine 5'-triphosphate (ATP), adenosine 5'-diphosphate (ADP), adenosine 5'-monophosphate (AMP), phosphocreatine (PCr), and adenosine by the high-pressure liquid chromatography (HPLC) technique and lactate spectrophotometrically. After 2 weeks, permanent 2-vo led to a significant decrease in the concentrations of cortical tissue ATP and PCr, from 3.06+/-0.48 to 2. 09+/-0.28 and from 4.27+/-0.63 to 3.35+/-0.41 micromol/g, respectively. These changes were associated with a two-fold increase in AMP and adenosine. Acute systemic hypotension alone (non-preconditioning) reduced ATP and PCr drastically, to 0.97+/-0. 51 and 1.76+/-1.23 micromol/g. Tissue concentrations of lactate, AMP, and adenosine were markedly increased, three- to five-fold, in 'non-preconditioned' brain tissue. In contrast, after 2 weeks of 2-vo acute hypotension did not significantly alter the cortical energy state any further. The effects of preconditioning on tissue ATP and PCr were most pronounced at 5 min and 48 h after reperfusion. In conclusion, permanent 2-vo seems to activate compensatory mechanisms, which effectively protect the rat's cortical energy metabolism against an additional ischaemic attack ('preconditioning-like' effect).

Acute Disease↗

[Using an anesthesia information management system (AIMS) for documentation in a day care unit for ambulatory surgery].

UNLABELLED: From January 1997 until June 1999, the complete durations of stay of 3152 outpatients were entered into a computerized documentation system. The scope of the data entry went from patient admission to patient release. The objective was to determine the usefulness of the anaesthesia information management system (AIMS) in producing complete and high-quality documentation in the field of outpatient operations. Some aspects and results from routine work are presented here. METHOD: The system was installed in eight bedside computers, in addition to a further client connected to the existing AIMS via Ethernet. Patient medical courses were documented both preoperatively and postoperatively in outpatient bedsides until their discharge or admission. The online documentation software NarkoData (Version 4, Imeso GmbH, Hüttenberg, Germany) was used to document and store patient data in a database. This program contains all relevant information concerning the course of anaesthesia and outpatient duration of stay, including application of drugs, vital signs, observation times, and medical findings as well as the data sets of the German Society of Anaesthesiology and Intensive Care Medicine (DGAI), ICD, and ICPM. Data was analyzed by exporting from the database into a statistical program using "structured query language." RESULTS: Data sets of 3152 outpatients were entered into the online documentation software. Most (54.2%) of the ambulatory surgical procedures were performed by the Department of Traumatology. General Surgery followed with 16.0%, and Urology managed 9.5% of the cases. The most frequent ambulatory surgical procedures were: diagnostic arthroscopy (923, 31.2%), removal of osteosynthetic material (410, 13.8%), and circumcision (250, 8.4%). Anesthesia procedures consisted of inhalative (38.6%, n = 1218) and intravenous anesthesia (IVA) (29.9%, n = 938). In 22.6% (713) of the cases, regional anaesthesia was performed. The average postoperative observation time was 289.2 +/- 140.1 minutes. One hundred sixty-nine patients (5.4%) were unexpectedly admitted to overnight care. The decision to admit patients to normal wards took place within the first 3 postoperative hours in 51.9% of the cases. CONCLUSION: The AIMS described above is sufficient in documenting the entire care process of patients in a day care unit. Integration into the existing AIMS was an important prerequisite for the integrity of the documentation chain. This allowed for a sensitive communication with other clinical data processing systems. The quality of documentation and flow of information at the workplaces in the day care unit were increased, similarly to other anaesthesiological workplaces in the hospital. Medical and administrative data and information for analyses of clinical processes are possible with such tools.

Adult↗

[Measurement of local oxygen parameters for detection of cerebral ischemia. The significance of cerebral near-infrared spectroscopy and transconjunctival oxygen partial pressure in carotid surgery].

UNLABELLED: The principle of, "selective shunting" during carotid endarterectomy requires a special concept to monitor neuronal function. The valence of the oxymetric methods, "near-infrared" spectroscopy (NIRS) and conjunctival oxygen tension (pcjO2) was determined with the reference method somatosensory evoked potentials (SEP). METHODS: In 41 patients undergoing reconstructive surgery on the internal carotid artery, recordings of the different methods were obtained under control, during carotid occlusion and during reperfusion. Cerebral ischemia was assumed if a complete loss of SEP appeared and an intraluminal shunt was placed. Conjunctival oxygen tension was measured continuously and simultaneously on the ipsi- and contralateral eye. RESULTS: In comparison to the reference method (SEP) the sensitivity and specificity of NIRS was 80% and 94%, respectively. The occlusion induced reduction of NIRS appeared 6.5 +/- 3.2 min earlier than the corresponding loss of SEP. Biocular determination of conjunctival oxygen tension was not able to detect hypoperfusion dependent ischemia during carotid occlusion. CONCLUSION: During carotid endarterectomy the measurement of conjunctival oxygen tension is not useful to detect cerebral ischemia. The use of NIRS as a single neuronal monitor is not appropriate to perform, "selective shunting". In contrast to SEP, however, NIRS is characterized by its rapid changes immediately following carotid occlusion. This non invasive method is likely to complete the standard method SEP in a modified monitoring concept of neuronal function during carotid endarterectomy.

Blood Gas Monitoring, Transcutaneous↗

Clinical and practical requirements of online software for anesthesia documentation an experience report.

The aim of this paper is the presentation of a new version of the anesthesia documentation software, NarkoData, that has been used in routine clinical work in our department as part of an anesthesia information management system (AIMS) since 1995. The performance of this software is presented along with requirements for future development of such a system. The originally used version, NarkoData 3.0, is an online anesthesia documentation software established by the software company ProLogic GmbH. It was primarily developed as a disk-based system for the MacOS operating system (Apple Computer Inc.). Based on our routine experience with the system, a catalogue of requirements was developed that concentrated on improvement in the sequence of work, administration and data management. In 1996, the concepts developed in our department, in close co-operation with medical personnel and the software company, led to a considerable enlargement of the program functions and the subsequent release of a new version of NarkoData. Since 1997, more than 20 000 anesthesia procedures have been recorded annually with this new version at 115 decentralized work stations at our university hospital.

Anesthesiology↗

Efficacy of continuous insufflation of oxygen combined with active cardiac compression-decompression during out-of-hospital cardiorespiratory arrest.

BACKGROUND: During experimental cardiac arrest, continuous insufflation of air or oxygen (CIO) through microcannulas inserted into the inner wall of a modified intubation tube and generating a permanent positive intrathoracic pressure, combined with external cardiac massage, has previously been shown to be as effective as intermittent positive pressure ventilation (IPPV). METHODS: After basic cardiorespiratory resuscitation, the adult patients who experienced nontraumatic, out-of-hospital cardiac arrest with asystole, were randomized to two groups: an IPPV group tracheally intubated with a standard tube and ventilated with standard IPPV and a CIO group for whom a modified tube was inserted, and in which CIO at a flow rate of 15 l/min replaced IPPV (the tube was left open to atmosphere). Both groups underwent active cardiac compression-decompression with a device. Resuscitation was continued for a maximum of 30 min. Blood gas analysis was performed as soon as stable spontaneous cardiac activity was restored, and a second blood gas analysis was performed at admission to the hospital. RESULTS: The two groups of patients (47 in the IPPV and 48 in the CIO group) were comparable. The percentages of patients who underwent successful resuscitation (stable cardiac activity; 21.3 in the IPPV group and 27.1% in the CIO group) and the time necessary for successful resuscitation (11.8 +/- 1.8 and 12.8 +/- 1.9 min) were also comparable. The blood gas analysis performed after resuscitation (8 patients in the IPPV and 10 in the CIO group) did not show significant differences. The arterial blood gases performed after admission to the hospital and ventilation using a transport ventilator (seven patients in the IPPV group and six in the CIO group) showed that the partial pressure of arterial carbon dioxide (PaCO2) was significantly lower in the CIO group (35.7 +/- 2.1 compared with 72.7 +/- 7.4 mmHg), whereas the pH and the partial pressure of arterial oxygen (PaO2) were significantly higher (all P < 0.05). CONCLUSIONS: Continuous insufflation of air or oxygen alone through a multichannel open tube was as effective as IPPV during out-of-hospital cardiac arrest. A significantly greater elimination of carbon dioxide and a better level of oxygenation in the group previously treated with CIO probably reflected better lung mechanics.

Adolescent↗

Comparative analysis of antibody responses against HSP60, invariant surface glycoprotein 70, and variant surface glycoprotein reveals a complex antigen-specific pattern of immunoglobulin isotype switching during infection by Trypanosoma brucei.

During Trypanosoma brucei infections, the response against the variant surface glycoprotein (VSG) of the parasite represents a major interaction between the mammalian host immune system and the parasite surface. Since immune recognition of other parasite derived factors also occurs, we examined the humoral host response against trypanosome heat shock protein 60 (HSP60), a conserved antigen with an autoimmune character. During experimental T. brucei infection in BALB/c mice, the anti-HSP60 response was induced when parasites differentiated into stumpy forms. This response was characterized by a stage-specific immunoglobulin isotype switching as well as by the induction of an autoimmune response. Specific recognition of trypanosome HSP60 was found to occur during the entire course of infection. Immunoglobulin G2a (IgG2a) and IgG2b antibodies, induced mainly in a T-cell-independent manner, were observed during the first peak of parasitemia, whereas IgG1 and IgG3 antibodies were found at the end of the infection, due to a specific T-cell-mediated response. Comparative analysis of the kinetics of anti-HSP60, anti-invariant surface glycoprotein 70 (ISG70), and anti-VSG antibody responses indicated that the three trypanosome antigens give rise to specific and independent patterns of immunoglobulin isotype switching.

Animals↗