Search PubMed⌕ Search

Biomedical subjects

H Bauer

Publications and source records attributed to H Bauer.

At least 73 records · Page 4Linked to original sources
PubMed1998

Follistatin and noggin are excluded from the zebrafish organizer.

The patterning activity of the Spemann organizer in early amphibian embryos has been characterized by a number of organizer-specific secreted proteins including Chordin, Noggin, and Follistatin, which all share the same inductive properties. They can neuralize ectoderm and dorsalize ventral mesoderm by blocking the ventralizing signals Bmp2 and Bmp4. In the zebrafish, null mutations in the chordin gene, named chordino, lead to a severe reduction of organizer activity, indicating that Chordino is an essential, but not the only, inductive signal generated by the zebrafish organizer. A second gene required for zebrafish organizer function is mercedes, but the molecular nature of its product is not known as yet. To investigate whether and how Follistatin and Noggin are involved in dorsoventral (D-V) patterning of the zebrafish embryo, we have now isolated and characterized their zebrafish homologues. Overexpression studies demonstrate that both proteins have the same dorsalizing properties as their Xenopus homologues. However, unlike the Xenopus genes, zebrafish follistatin and noggin are not expressed in the organizer region, nor are they linked to the mercedes mutation. Expression of both genes starts at midgastrula stages. While no patterned noggin expression was detectable by in situ hybridization during gastrulation stages, later expression is confined to presumptive cartilage cells in the branchial arches and the neurocranium and to proximal regions of the pectoral fin buds. follistatin transcripts in gastrulating embryos are confined to anterior paraxial regions, which give rise to head mesoderm and the first five somites. The dorsolateral extent of this expression domain is regulated by Bmp2b, Chordino, and Follistatin itself. In addition, transient expression was observed in a subset of cells in the posterior notochord anlage. Later, follistatin is expressed in brain, eyes, and somites. Comparison of the spatiotemporal expression pattern of follistatin and noggin with those of bmp2b and bmp4 and overexpression studies suggest that Noggin and Follistatin may function as Bmp antagonists in later processes of zebrafish development, including late phases of D-V patterning, to refine the early pattern set up by the interaction of Chordino and Bmp2/4. It thus appears that many, but not all, aspects of early dorsoventral patterning are shared among different vertebrate species.

Amino Acid Sequence↗
PubMed1998

Breaking Rotational Symmetry in a Self&hyphenOrganizing Map Model for Orientation Map Development

We analyze the pattern formation behavior of a high&hyphendimensional self&hyphenorganizing map (SOM) model for the competitive projection of ON&hyphencenter&hyphentype and OFF&hyphencenter&hyphentype inputs to a common map layer. We mathematically show, and numerically confirm, that even isotropic stimuli can drive the development of oriented receptive fields and an orientation map in this model. This result provides an important missing link in the spectrum of pattern formation behaviors observed in SOM models. Extending the model by including further layers for binocular inputs, we also investigate the combined development of orientation and ocular dominance maps. A parameter region for combined patterns exists; corresponding maps show a preference for perpendicular intersection angles between iso&hyphenorientation lines and ocularity domain boundaries, consistent with experimental observations.

Journal Article↗
PubMed1998

[Intradermal hepatitis B vaccination in workers not responsive to intramuscular vaccination].

Health care workers are at continuous risk of hepatitis B infection. Currently recommended intramuscular vaccination confers immunity in only 85-90%. We examined the immunogenicity and safety of intradermal vaccination of hepatitis B vaccine in nonresponders. 400 hospital employees who had been immunized as recommended were screened for anti-HBs antibodies and 50 were found seronegative. Each received an intramuscular booster injection and antibody level was measured a month later. Excluded were 33 employees, including 24 late responders, 2 HbsAg carriers and 7 uncooperative employees. 17 employees (mean age 47.1 yrs) then received a series of 3 intradermal injections of Energix B, 0.25 ml in the forearm, 2-3 weeks apart. The mean number of previous intramuscular injections was 4.6 +/- 1.4. A month later there was a mean titer of 315.4 +/- 347.0 miu/ml of antibody in 16/17 workers. Side effects were minimal. Intradermal injection of hepatitis B vaccine for nonresponders seems effective for inducing seroconversion. Its cost-effectiveness for the health care system warrants assessment.

Adult↗
PubMed1998

[Must the accident victim be protected from the emergency physician?].

Quality control in preclinical medical care has become a matter of concern in recent years. In order to evaluate the quality of treatment one has to set standards. Most of the current standards were defined by different preclinical care organisations and are also accepted in the unique emergency medical care protocol used in the Federal Republic of Germany. Considering these standards, we retrospectively analyzed the preclinical treatment of all multiple trauma patients admitted to our department between 1985 and 1996. The major issues of this analysis were the diagnoses, the indications for invasive measures and the performance. Regarding the triage, for example, it was noted that 28% of patients who should have been admitted to a level I trauma center considering the severity of their injury were first admitted to a level III hospital and needed to be transferred later. In 7% of patients two additional mistakes and in 4% of patients more than two mistakes in the triage were noted. On the other hand, there are records of patients who were considered to be only slightly injured but received invasive treatment. Preclinical intubation and mechanical ventilation was not performed in 16.5% although the severity of injury clearly demanded it. A thoracic drain tube was not positioned in 38% of patients suffering from severe thoracic trauma (AISThorax > or = 4). Insufficient application of resuscitation volume (< 2500 ml on admission) was evident in 17% of all documented patients. According to our results, the initial evaluation of severity of injury is still a major problem and leads to wrong decisions for treatment. Although the qualification of ambulance physicians has been standardized for some years, there are still clear deficits in the preclinical management of trauma patients that need to be targeted.

Adult↗
PubMed1998

Cardiac output measurement by transpulmonary versus conventional thermodilution technique in intensive care patients after coronary artery bypass grafting.

OBJECTIVE: The aim of the present study was to evaluate the correlation, accuracy, and precision of transpulmonary thermodilution cardiac output (CO) measurement. For this purpose, this technique was compared with the clinical gold standard, the CO measurement by pulmonary artery catheter in patients after coronary artery bypass grafting (CABG). DESIGN: A prospective clinical study. SETTING: A university medical center. PARTICIPANTS: Seventy-five patients in an intensive care unit (ICU) after CABG. INTERVENTIONS: Standard (SCO) and transpulmonary thermodilution CO measurement (TPCO) measurements were simultaneously performed in triplicate by central venous injection of cooled saline solution. All variables were recorded at five different time points of measurement during weaning from mechanical ventilation. MEASUREMENTS AND MAIN RESULTS: CO measurements yielded 375 data pairs. SCO ranged from 2.0 to 10.2 L/min, and TPCO from 1.3 to 10.6 L/min. During the entire observation period, TPCO measurements tended to yield relatively high values, whereas SCO measurements resulted in lower values. Correlation between TPCO and SCO measurements was significant (r = 0.73; p < 0.05), accompanied by an accuracy with a bias of 0.456 L/min (7.3%) and a precision of 1.156 L/min (18.5%). CONCLUSION: In most patients, TPCO measurement will not replace the conventional technique by pulmonary artery catheter, but in some patients it offers an attractive, reliable, and safe method to determine CO.

Aged↗
PubMed1998

Double-blind, multicenter comparative study of sertraline and amitriptyline in hospitalized patients with major depression.

Sertraline is a selective serotonin reuptake inhibitor (SSRI) for which marketing approval has been obtained recently in Germany. The results of several double-blind, placebo-controlled studies have demonstrated that sertraline has a clear antidepressive effect. However these studies have been conducted in outpatient populations. In the context of this multicenter study, a total of 160 inpatients were treated with sertraline 50-150 mg or amitriptyline 75-225 mg over a period of 6 weeks in a double-blind fashion. Sixty-two patients in the sertraline and 59 patients in the amitriptyline group were evaluated for efficacy in the according-to-protocol (ATP) population; 80 sertraline and 75 amitriptyline patients were evaluated for safety in the Intention-to-treat population (ITT). No statistically significant differences were detected between the two groups in the efficacy analysis performed on the basis of the Hamilton Depression Scale (HAM-D) total score and Clinical Global Impression (CGI). Due to its sedating properties, amitriptyline was found to be significantly more effective with regard to the HAM-D factor "sleep disturbance". The safety analysis, which was based on the CGI, the global assessment at the end of study and a score for somatic adverse events (FSUCL) revealed statistically significant advantages of sertraline over amitriptyline. Amitriptyline was associated with more autonomic and circulatory side effects, while epigastric complaints occurred more often with sertraline. The incidence of nausea - a typical SSRI side effect - was the same in both groups.

Adrenergic Uptake Inhibitors↗
PubMed1998

Stability of local anesthetics in heparinized blood, plasma and sulfuric acid.

BACKGROUND: This study was undertaken to investigate the stability of local anesthetics in different media. METHODS: 60 patients with axillary plexus block, using prilocaine, mepivacaine or lidocaine 1%, or with lumbar epidural catheter-anesthesia, using bupivacaine 0.5%, were investigated. Stability was evaluated in heparinized whole blood for 24 h at +4 degrees C, in plasma for 8 week at -25 degrees C and in sulfuric acid for 6 months at -25 degrees C. RESULTS: Mean recovery rates were between 96.4% and 102.6% in all local anesthetics and media. No statistical significance became obvious for differences between recovery rates and initial values. CONCLUSION: Stability of prilocaine, mepivacaine, lidocaine and bupivacaine can be expected when samples are stored as heparinized whole blood for 24 h at +4 degrees C, plasma for 8 weeks at -25 degrees C, and after preparation into sulfuric acid for 6 months at -25 degrees C.

Anesthesia, Epidural↗
PubMed1998

Personality disorders in pulmonary patients.

A sample of 59 patients with asthma and chronic obstructive pulmonary diseases (COPD) was compared to matched samples of psychiatric patients and normal individuals with respect to personality disorders (PDs) assessed by a self-report measure (VKP) (Duijsens, Eurelings-Bontekoe, Diekstra & Ouwersloot, 1993a, b). The number of PDs differed significantly between pulmonary and psychiatric patients, while there was no significant difference between pulmonary patients and normal individuals. Comparison of the number of diagnosis criteria yielded significant contrasts between psychiatric patients versus the normal individuals and the pulmonary patients. Pulmonary patients and normal individuals showed significantly lower mean number of criteria met than matched psychiatric patients for nearly all of the diagnoses. It is concluded that PDs are no more prevalent in asthma and COPD patients than in the general population.

Adult↗
PubMed1998

[The image of surgery in public opinion].

Surgery and surgeons have a direct relationship to publicity. In the media, the entertainment aspect prevails over information (infotainment), and scandal also dominates because of negative reports. The cause in many cases is a lack of information, which is always a problem when transmitting scientific information to the public. Economic pressures and diminished resources as well as a simultaneous increase in the demands made on medicine make it mandatory that surgeons communicate properly. They are being degraded more and more to "delivering" medicine, and the relationship between the surgeon and his patient has been reduced to a collision of greediness on both sides. We are in continuous conflict with the power of the media and are being challenged to improve our public relations. The public image of surgery today is determined by surgical performance and competence in communication.

Clinical Competence↗
PubMed1998

[Additional qualifications in "special pain therapy"--an advantage to surgeons as well?].

Deficits in the treatment of patients with chronic pain lead the German Parliament of Physicians (Deutscher Arztetag) in 1996 to adapt a special curriculum called "Special Pain Treatment". Objectives and contents are defined in detail in guidelines accepted from 10 out of 17 federal commissions in Germany at this time. Because transitional regulations have been administered until now, surgeons have not yet been required to obtain the qualification. The prescribed curriculum and particularly the contract between the association of general practitioners and the insurance companies make the acquisition of the qualification and the permission to use it in private practice covered by insurance very difficult for surgeons.

Chronic Disease↗
PubMed1997

Measurement of nitrite and nitrate in biological fluids by gas chromatography-mass spectrometry and by the Griess assay: problems with the Griess assay--solutions by gas chromatography-mass spectrometry.

Assay methods based on the Griess reaction are frequently used to measure nitrite and nitrate in urine, plasma, and other biological fluids. With minor exceptions, careful attention has not been paid in extending the Griess assay from aqueous solutions to biological fluids, In the present study, parallel measurements of nitrite and nitrate were performed in urine, plasma, and aqueous solutions with a published batch assay based on the Griess reaction and with gas chromatography-mass spectrometry (GC-MS). We report here further interferences by free reduced thiols, proteins, and other plasma constituents in the Griess assay but not in GC-MS. The best correlation (r2 = 0.985) between the Griess assay and GC-MS was observed for aqueous solutions in the absence of thiols. Unlike GC-MS, the Griess assay was not applicable to whole human plasma and urine samples. For the measurement of nitrate in diluted human urine samples, reduction by cadmium was performed both under acidic (pH 2 or 5) and alkaline (pH 8.8) conditions. The mean recovery rate of nitrate from urine samples was quantitative in the GC-MS but amounted to only 30-80% in the Griess assay. Measurement of nitrate in human urine samples (n = 33) resulted in an excellent correlation between two GC-MS techniques (r2 = 0.979) but only in a poor correlation (r2 < 0.64) between the Griess assay and GC-MS. Unlike GC-MS, the batch Griess assay is associated with many problems in measuring nitrate in biological fluids.

Chromatography, High Pressure Liquid↗
PubMed1997

Coexisting hyperparathyroidism, renal osteodystrophy and psoriatic arthritis.

We report the case of a 60-year-old woman with hyperparathyroidism, renal osteodystrophy and psoriatic arthritis. The coexistence of findings of hyperparathyroidism and renal osteodystrophy has been described and there are also reports of patients suffering from renal arthropathy mimicking hyperparathyroidism. To our knowledge, there is no description to date of a case displaying findings of the co-occurrence of these conditions in a patient. We would like to emphasize that attention should be paid to the possible diagnosis of a coexisting inflammatory rheumatic disease when rheumatological symptoms of recent onset occur in patients with long-standing renal osteodystrophy and/or symptoms mimicking hyperparathyroidism occur in these patients.

Arthritis, Psoriatic↗