Biomedical subjects

O Braun

Publications and source records attributed to O Braun.

At least 19 recordsLinked to original sources

PubMed2005

Force spectroscopy of single multidomain biopolymers: a master equation approach.

Experiments using atomic force microscopy for unfolding single multidomain biopolymers cover a broad range of time scales from equilibrium to non-equilibrium. A master equation approach allows to identify and treat coherently three dynamical regimes for increasing linear ramp velocity: i) an equilibrium regime, ii) a transient regime where refolding events still occur, and iii) a saw-tooth regime without any refolding events. For each regime, analytical approximations are derived and compared to numerically investigated examples. We analyze in the framework of this model also a periodic experimental protocol instead of a linear ramp. In this case, a major simplification arises if the dynamics can be restricted to an effectively two-dimensional subspace. For transitions with an intermediate meta-stable state, like Immunoglobulin27, a refined model allows to extract previously unknown molecular parameters related to this meta-stable state.

Algorithms↗

PubMed1997

[Aspects of auditory speech perception in cochlear implant and hearing aid managed children].

Speech perception is a valuable tool for the assessment of auditory (re-)habilitation of children with hearing impairments. We tested 3 groups of prelingually deaf children. For the evaluation of speech recognition abilities the test of auditory perception of speech in children (TAPS) was used. Hearing aid fitted children of a school for hard of hearing and school of the deaf (n = 12 and n = 10, respectively) and cochlear implant users (n = 12) of the same age group were tested. A positive correlation of the speech perception abilities with the aided thresholds was found. Hearing aid fitted children of the school of hard of hearing with aided thresholds between 20 and 40 dB HL including 4000 Hz showed best results. Students of the same school with aided thresholds in the range of 45 to 70 dB HL performed comparable to the lesser cochlear implant users fitted with a single channel analogue system. Hearing aid fitted students of a school for the deaf with the same degree of hearing loss and amplification showed significantly poorer results.

Auditory Threshold↗

PubMed1994

Chest X-ray in collagen vascular diseases. A comparison of chest X-ray with bronchoalveolar lavage and transbronchial forceps biopsy.

The diagnostic value of chest X-ray following the ILO standards was compared with bronchoalveolar lavage (BAL) and the histology of transbronchial forceps biopsy in 83 patients with collagen vascular diseases. BAL in the middle lobe was considered abnormal in case of increased cell count per milliliter and/or lymphocytosis and/or neutrophil granulocytosis and this was found in 32 out of 42 cases (76.2%) with, and in 33 of out 41 cases (80.5%) without abnormal radiological finding. Pathological changes in the histology were found in 14 out of 20 cases (70.0%) with and in 40 out of 63 cases (63.5%) without abnormal chest X-ray in the upper lobe from which the transbronchial forceps biopsy specimens were obtained. In histological specimens obtained from transbronchial forceps biopsy, only fibrosis correlated with abnormal radiological findings in this region. Other inflammatory processes defied prediction by chest X-ray. This suggests that, regardless of chest X-ray findings, BAL should be performed together with transbronchial forceps biopsy for the histological examination of patients with collagen vascular diseases in which interstitial lung involvement is suspected.

Adolescent↗

PubMed1993

EMS system performance: the use of cardiac arrest timelines.

The time data used to analyze the significance of time-to-treatment intervals on times from sudden cardiac arrest vary by definition of time and individual system design, making it difficult to compare these data and to extrapolate findings from one study to another to achieve generalizable conclusions. A model is proposed to describe the time-to-treatment/time-to-patient response intervals sought by most researchers to evaluate quality of care and system performance. It provides a mechanism for incorporating system design elements into the cardiac arrest timeline proposed by the Utstein Conference. The present model is composed of generic patient management intervals (classes of intervals common to all systems) that are composed of component intervals (intervals particular to each system) that describe the system's conduct of an emergency medical services call, which, in turn, are constructed of data (activity) points unique to each system. Because each system defines its own data points, the present model permits rigorous definition and analysis of the time data produced by all systems. Each system thereby constructs reliable component intervals, producing a system-specific, real-time depiction of the events related to a cardiac arrest call. Because all systems share the same generic patient management intervals, the resulting cardiac arrest timeline can be compared with those from other systems to assess system performance. The goal of the present model is to facilitate further the standardization of cardiac arrest data acquisition and reporting and evaluation of emergency medical services system performance.

Data Collection↗

PubMed1993

Prehospital cardiac arrest treated by urban first-responders: profile of patient response and prediction of outcome by ventricular fibrillation waveform.

STUDY OBJECTIVES: To determine the speed and characteristics of patient response to urban first-responder defibrillation and to determine whether amplitude of ventricular fibrillation (VF) can predict outcome in these patients. TYPE OF PARTICIPANTS: All adult patients in prehospital VF treated by fire department first-responders (265). DESIGN AND INTERVENTIONS: A prospective observational study occurring between February 1, 1989, and January 1, 1991. Patients were defibrillated according to advanced cardiac life support and first-responder protocols. ECG and time data were recorded digitally. MAIN RESULTS: Sixty-five percent of patients converted from VF to a more stable rhythm at least once during first-responder monitoring. Fifty-four percent of converted patients refibrillated at least once, and 42% of all stable conversions occurred after at least one episode of refibrillation. Seventy percent of all refibrillations occurred less than six minutes after the defibrillator was turned on, and 23% occurred after more than ten minutes. The proportion of stable conversions decreased from 30% on first conversion to 2% on fourth conversion. With each successive conversion the interval to refibrillation grew shorter, and development of a pulse or blood pressure became less likely. Presence of blood pressure or pulse after conversion had a sensitivity for hospital discharge of 54% and a specificity of 98%. Maximum VF amplitude before countershock was highly predictive of postshock rhythm, stable conversion in the field, time interval before refibrillation, inpatient admission, and hospital discharge. VF amplitude was unrelated to response interval or interval to defibrillation but was positively related to bystander CPR. Logistic regression identified VF amplitude as the most important predictor of hospital discharge; traditional variables such as response interval and bystander CPR were not predictive once amplitude had been accounted for. Changes in VF amplitude during the course of resuscitation efforts were frequent and also predictive of outcome. CONCLUSION: Patients in VF who were treated by early countershock refibrillated much more frequently than previously reported. Refibrillations occur both early and late. Initial VF maximum amplitude is strongly predictive of outcome. Future reports of VF cardiac arrest should control for this previously neglected variable. Increased amplitude of VF during repeated refibrillation episodes is associated with increased hospital discharge, so future studies of advanced cardiac life support interventions should explore changes in VF amplitude as an outcome variable.

Aged↗

PubMed1993

Lung involvement in rheumatoid factor-negative arthritis.

Bronchoalveolar lavage (BAL) was performed on 13 asymptomatic patients with sero (rheumatoid factor)-negative arthritis (SNA); (6 with peripheral psoriatic arthritis, 2 with axial psoriatic arthritis, 3 with ankylosing spondylitis, 2 with sacroiliitis). BAL revealed a significant decrease of neutrophil granulocytes and an increase of B-lymphocytes in patients with SNA in comparison with 64 patiénts with rheumatoid arthritis (RA; 24 seronegative, 39 seropositive) and 15 healthy controls. Patients with SNA and RA had a significant increase of lymphocytes, especially T, T-helper and activated cells. In addition patients with RA had a significant increase of natural killer cells and a lower percentage of alveolar macrophages and T-suppressor cells. Transbronchial biopsy was performed on 9 patients with SNA and on 59 patients with RA. Abnormal histologic features of lung tissue were observed in 4 out of 9 patients with SNA (2 with fibrosis, 1 with follicular lymphoid hyperplasia, 1 with desquamative interstitial pneumonitis). The abnormal lung histology in RA patients was more pronounced, however, the differences between SNA and RA were not significant. The data from BAL and histology suggest, that the pulmonary involvement in SNA and RA is caused by an unspecified immunologic process.

Adult↗

PubMed1993

Bronchoalveolar lavage and lung biopsy in rheumatoid arthritis. In vivo effects of disease modifying antirheumatic drugs.

Bronchoalveolar lavage (BAL) and histology of transbronchial forceps biopsy was performed in 59 patients with rheumatoid arthritis (RA) to evaluate the in vivo effects of disease modifying drugs (DMARD). All patients had no clinical pulmonary symptoms and there was no evidence of drug induced alveolitis. Patients were divided into 5 subgroups according to drug treatment: 9 patients taking chloroquine, 15 patients gold, 8 patients penicillamine, 8 patients methotrexate (MTX) and 19 patients not taking DMARD. Duration of DMARD regimen was more than 3 months. No patient was treated with corticosteroids. BAL results revealed an increased percentage of lymphocytes and a diminished proportion of alveolar macrophages in patients treated with gold, penicillamine, MTX and no DMARD. In contrast, patients receiving chloroquine had a normal distribution of lymphocytes and macrophages as seen in a control group of 15 persons. Patients taking MTX showed a normal distribution of T and B lymphocytes and DR positive cells, whereas patients receiving chloroquine, gold, or penicillamine had an elevated proportion of T lymphocytes and DR positive cells and a diminished percentage of B lymphocytes. The latter was also observed in patients not taking DMARD. The percentage of natural killer cells was significantly elevated only in the penicillamine group. Patients receiving gold had higher absolute values of CD3, CD4 and DR positive cells. Abnormal lung histology was associated with an increased percentage of lymphocytes and with higher DR positive cells in BAL. Patients not receiving DMARD had a significantly higher percentage (42.1%) of abnormal histologic features of lung tissue than patients receiving DMARD (17.5%).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1992

Nucleolar silver staining patterns and HLA-DR antigen expression in bronchial epithelial cells in chronic bronchitis.

Bronchial epithelial cells obtained by brush biopsy during fiberoptic bronchoscopy performed in 12 patients with chronic bronchitis and 12 healthy control subjects, were investigated for HLA-DR antigen expression and nucleolar silver staining patterns. In all patients with chronic bronchitis the number of bronchial epithelial cells positive to HLA-DR antigen was highly increased (> 90%), whereas in the controls only a few epithelial cells (< 10%) showed a weak HLA-DR antigen expression. Patients with chronic bronchitis showed an increased lymphocytic reaction compared to the control subjects. Both in the patients with chronic bronchitis and in the healthy controls the number of nucleoli was the same. The number of silver stained dots per nucleus was significantly higher in patients with chronic bronchitis than in the control subjects (7.70 +/- 0.87 as against 5.11 +/- 0.52; p < 0.0001). The intensity of the lymphocytic reaction correlated with the HLA-DR antigen expression and the increase in silver staining (Spearman's r = 0.543; p < 0.01). This indicates the influence of inflammation on the activation of epithelial cells derived from the respiratory tract.

Adult↗

PubMed1992

Nucleolar silver staining patterns of lymphocytes in sarcoidosis.

Bronchoalveolar lavage lymphocytes from 15 patients with pulmonary sarcoidosis and 8 healthy controls were investigated for nucleolar silver staining patterns and lymphocyte subpopulations. Patients with sarcoidosis had increased numbers of silver stained dots versus controls (2.20 +/- 0.24 versus 1.78 +/- 0.07; p less than 0.001). The number of silver stained dots showed the strongest positive correlation to helper cells (OKT 4+) (r = 0.781; p less than 0.0001). These results may be interpreted as further evidence of lymphocytic activation, especially of helper cells (OKT 4+) in pulmonary sarcoidosis.

Adult↗

PubMed1992

Prediction of interstitial lung involvement in rheumatoid arthritis. The value of clinical data, chest roentgenogram, lung function, and serologic parameters.

We initiated the present study to predict interstitial lung involvement in rheumatoid arthritis (RA) by means of logistic regression analysis of clinical data, lung function, chest roentgenogram, and serologic parameters. Fifty-eight nonsmoking patients with RA were randomized from the rheumatologic unit and sent for investigation to the pulmonary department. Bronchoalveolar lavage (BAL) was performed in the middle lobe and the BAL fluid was considered abnormal in case of increased cell count per milliliter and/or lymphocytosis and/or neutrophil granulocytosis; these findings or combinations thereof were found in 42 (72.4 percent) of 58 cases. The patients' data that had an impact on the normality of BAL were the sex (p = 0.001), vital capacity (p = 0.028), peripheral blood T-helper cells (OKT4+) (p = 0.025), DR(+)-lymphocytes (p = 0.002), and antinuclear antibodies (p = 0.025). By means of the logistic regression analysis, it was possible to reach high significance in the prediction of interstitial lung involvement, with a sensitivity of 92.9 percent and a specificity of 75.0 percent (p less than 10(-6)). The efficiency of prediction was 87.9 percent. From these results, we conclude that interstitial lung involvement in RA is predictable from laboratory findings that have been yielded by noninvasive diagnostic techniques. These data should be used in clinical routine monitoring and they may help to facilitate the assessment of whether bronchoscopy is indicated.

Arthritis, Rheumatoid↗

PubMed1991

Combined modality treatment of advanced cancers of the oral cavity and oropharynx.

From May 1985 to June 1988, 70 evaluable patients with advanced squamous cell cancers of the oral cavity and the oropharynx were treated with preoperative combined radio-chemotherapy. Treatment consisted of 50 Gy/25 fractions/5 weeks, combined with concomitant administration of mitomycin C on day 1 (15 mg/m2, i.v. bolus) and 5-fluorouracil during the first 5 days of irradiation (750 mg/m2/24 hours, continuous infusion). Surgery was performed 3 to 5 weeks following irradiation. Treatment tolerance was good and local mucosal reaction was increased, but no major systemic side effects were recorded. At surgery, 3-5 weeks following irradiation, 48.6% of the operation specimens did not contain any histologically detectable residual tumor. Overall survival is 61%, being 69% in T2 and T3, while none of the patients with bone invasion has survived. Median survival is 28, 26, and 9 months in T2, T3 and T4 stages, respectively. Loco-regional relapses have been recorded in 33% of the patients, occurring in 27% of T2, 25% of T3, and 88% of T4 stages. Patients have been spared mutilating radical neck dissection because of combined presurgical treatment without impaired survival or loco-regional relapse rate.

Adult↗

PubMed1991

[Histologic study of the effect of postoperative irradiation on free transplanted jejunal segments].

After the reconstruction of defects resulting from the resection of advanced tumors from the upper aerodigestive tract using free microvascular anastomized jejunum, the autotransplant is influenced by local radiotherapy (cumulative dose 50-70 Gray). Biopsies were taken from 15 patients, stained with haemotoxilin-eosin and Giemsa and compared by means of light microscopy with jejunum taken at the time of transplantation. It was possible to observe a widened mucosal and submucosal space two to three months after radiotherapy, similar to the clinical impression of a radiogenic enteritis. The villi were flat and shortened with no or slight epithelial lesions. Additionally, it was possible to observe an inflammatory infiltration consisting mainly of neutrophilic granulocytes, edemas, and telangiectases. The latter were also evident in nonirradiated autotransplanted jejunum and are therefore not only caused by irradiation. One year after radiotherapy the mucosal membrane was atrophic. Fibrosis was to be seen in the lamina propria, accompanied by widened muscularis mucosae. The submucosal space was also widened and fibrotic to a varying degree. It was possible to detect varying stages of alteration in the vascular system up to a complete obliteration. After two years, changes were more pronounced. At no time could any alteration in the nervous system of the plexus submucosus be observed. All of these changes have to be interpreted as a consequence of irradiation. However, lubrication of the mucosal surface and the motility of the transplant are not altered severely by irradiation and therefore the desired functions of the free transplanted jejunal grafts, such as swallowing and phonation, are carried out sufficiently.(ABSTRACT TRUNCATED AT 250 WORDS)

Biopsy↗

PubMed1991

Personal spore sampling and indirect immunofluorescent test for exploration of hypersensitivity pneumonitis due to mould spores.

Sensitization to mould spores was investigated in six patients with hypersensitivity pneumonitis, eight patients with idiopathic lung fibrosis, and six healthy controls by immunodiffusion and immunofluorescent testing of personal spore samples. The new technique of personal spore sampling with the Burkard personal volumetric air sampler and indirect immunofluorescent test for detection of spore-specific IgG and IgM confirmed that five patients with hypersensitivity pneumonitis and four with lung fibrosis were actually exposed and sensitized to moulds. Personal spore sampling and subsequent immunofluorescent tests represent sensitive tools for detection of individual mould sensitization and air quality control.

Adult↗

PubMed1990

Bronchoalveolar lavage in rheumatoid arthritis and secondary Sjögren's syndrome.

Bronchoalveolar lavage (BAL) was performed to investigate pulmonary involvement in 39 patients with rheumatoid arthritis (RA) and in 7 patients with RA and secondary Sjögren's syndrome, and compared to 12 healthy controls. Lymphocytosis (more than 15%) was seen in 25, and more than 3% neutrophil granulocytes in 8 of 39 patients with RA. Lymphocytosis and/or neutrophil granulocytosis was seen in both seropositive and seronegative patients irrespective of clinical or radiologic findings. Patients with RA with or without secondary Sjögren's syndrome had increased DR+ lymphocytes in BAL compared with peripheral blood. In 7 patients with secondary Sjögren's syndrome an increased helper/suppressor cell index (OKT4+/OKT8+: 7.65 +/- 2.10) and increased natural killer cells (OKNK+: 27.3 +/- 5.5%) were found, as compared to 39 other patients with RA (OKT4+/OKT8+: 2.16 +/- 0.33, p less than 0.05; OKNK+: 14.5 +/- 2.3%, p less than 0.05). These BAL data are further evidence of frequent subclinical interstitial pulmonary involvement in RA with differences in the active autoimmune process from those in secondary Sjögren's syndrome.

Aged↗

PubMed1990

Characteristics of midsized urban EMS systems.

Emergency medical services (EMS) systems in 25 midsized cities (population, 400,000 to 900,000) are described. Information describing EMS system configuration and performance was collected by written and telephone surveys with follow-ups. Responding cities provide either one- or two-tier systems. In a one-tier system, an advanced life support (ALS) unit responds to and transports all patients who use 911 to activate the system. Three types of two-tier systems are identified. In system A, ALS units respond to all calls. Once on scene, an ALS unit can turn a patient over to a basic life support (BLS) unit for transport. In system B, ALS units do not respond to all calls; BLS units may be sent for noncritical calls. In system C, a nontransport ALS unit is dispatched with a transporting BLS unit. For ALS calls, ALS personnel join BLS personnel for transport. Overall, cities staff an average of one ambulance per 51,223 population. One-tier systems average one ambulance per 53,291 compared with two-tier systems, which average one ambulance per 47,546. In the two-tiered system B, the average ALS unit serves 118,956 population. In the 60% of cities that use a one-tier system, one ALS unit serves 58,336 (P less than .0005). Overall, the code 3 response time for all cities is an average of 6.6 minutes. The average response time of two-tier systems is 5.9 minutes versus 7.0 minutes for one-tier systems (.05 less than P less than .1). These data suggest that the two-tiered system B allows for a given number of ALS units to serve a much larger population while maintaining a rapid code 3 response time.

Ambulances↗

PubMed1989

Increased expression of HLA-DR antigen on alveolar macrophages in pulmonary diseases.

The expression of HLA-DR antigen on alveolar macrophages obtained by bronchoalveolar lavage in healthy controls and patients with different diseases was investigated, using cytofluorographic analysis and phykoerythrin conjugated monoclonal mouse anti-human HLA-DR antibody. Alveolar macrophages in patients with extrinsic allergic alveolitis (n = 4), idiopathic lung fibrosis (n = 4), sarcoidosis (n = 6), rheumatoid lung disease (n = 6) and pulmonary infection (n = 5) showed increased density of HLA-DR antigen expression compared to healthy control subjects (n = 5). The increased expression of HLA-DR antigen on alveolar macrophages confirms the importance of these cells for recognition of antigens and immunological responses in different pulmonary diseases.

Bronchoalveolar Lavage Fluid↗

PubMed1989

Response to preoperative concomitant radiochemotherapy with mitomycin C and 5-fluorouracil in advanced head and neck cancer.

Advanced head and neck tumours have a poor prognosis due to the high frequency of local recurrence. Multimodality treatment has been shown to be effective in decreasing local recurrence. In this study, 51 patients with advanced oral and oropharyngeal carcinoma were entered in a trial of preoperative radio-chemotherapy. After exclusion of -10 protocol violations (no surgery or no chemotherapy), 41 patients remained evaluable. Chemotherapy consisted of 15 mg mitomycin C/m2 given intravenously (bolus) on day 1. 5-Fluorouracil (750 mg/m2/24 h) was infused during days 1-5 (continuous infusion for 120 h). Radiotherapy was performed simultaneously with chemotherapy beginning on day 1. A total dose of 50 Gy to the primary tumour and neck region was delivered over 5 weeks. Treatment was well tolerated. Side-effects were mainly of local character (mucositis). No severe systemic toxicity was seen. Some delayed wound healing was noted at the operation (4 weeks after irradiation). The CR rate of the primary tumours was 56% (23/41). In 39% (16/41) only histological residual tumour was found. Two patients had minor response (categorized as NR) of their tumour (macroscopic residual tumour). None had tumour progression. The response rates considering lymph node metastases were 59% (22/37) CR, 35% (13/37) PR and 5% (2/37) NR. After a follow up of 18-30 months, analysis of local recurrent disease and survival was performed. The loco-regional recurrence rate was 32% (13/41) and the survival rate 63% (26/41). All deceased patients, except two, died of tumour progression. Patients with T4 tumours showed inferior prognosis whereas no significant difference in survival of T2 and T3 patients was found. Patients with CR of tumour and lymph nodes (including NO) have all survived and are without evidence of disease.

Adult↗

PubMed1989

[The branchiogenic cyst in the oncologic context].

8 patients with cystic carcinoma resembling a lateral cervical cyst by morphology and topography are reported. In 4 cases an analogous carcinoma later appeared in the ipsilateral tonsil, and in 2 tonsillectomized patients subsequent carcinoma developed in the palatopharyngeal arch or at the base of the tongue respectively. One carcinomatous cyst with consecutive involvement of the base of the tongue was preceded by a regular branchiogenic cyst on the opposite side. Removal of a recurrent branchiogenic cyst in another patient revealed unsuspected chronic myeloic leukaemia infiltrating adjacent lymph nodes. The hypotheses regarding the branchiogenic and lymphogenic pathogenesis of such carcinomatous cysts are discussed. Diagnosis should be elaborated as in any carcinomatous lump of the neck and should include serial sectioning of the tonsils and imaging of deep layers. The possibility of synchronous or metachronous tonsillar involvement must always be taken into consideration.

Aged↗