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Biomedical subjects

T Bauer

Publications and source records attributed to T Bauer.

At least 19 recordsLinked to original sources
PubMed1998

[The diagnostic accuracy and therapeutic relevance of CT arthrography and MR arthrography of the shoulder].

PURPOSE: In glenohumeral instability, CT arthrography and MR arthrography of the shoulder joint were compared to assess accuracy in diagnosis of labral lesions and other internal derangements of the joint, and to evaluate relevance of both imaging methods for therapy. METHODS: 38 patients with symptoms of shoulder instability were examined clinically, arthrographically with CT and MRI, and arthroscopically. Arthrography with CT and MRI was performed in a double-contrast technique after single puncture and simultaneous injection of the contrast agents for both imaging methods. Type and extent of lesions on arthrographic imaging were criteria for planning therapy to a conservative, sole arthroscopic, or open surgical approach. RESULTS: Sensitivity in diagnosis of labral lesion (26 defects) was 85% in CT, 88% in MRI and 100% if both methods were used. Full-thickness tears of the rotator cuff were visualised in CT in 73%, and in MRI in 100%. Diagnostic accuracy increased from partial to complete to total defects. An open surgical approach was correctly predicted on MRI in 90% and on CT in 71%. A sole arthroscopic therapy was correctly foreseen on both arthrographic techniques in only 38% due to difficulties to assess glenohumeral ligaments. CONCLUSIONS: CT arthrography and MR arthrography were excellent for diagnosing labral lesions. MRI is superior to CT in the imaging of all joint structures. Surgical approach can be accurately predicted with both imaging methods but special surgical techniques cannot be effectively planned to replace diagnostic arthroscopy in all cases.

Adult↗
PubMed1997

Penicilloyl peptides are recognized as T cell antigenic determinants in penicillin allergy.

Although hapten immune responses have been intensively studied in the mouse, very little is known about hapten determinants involved in human allergic reactions. Penicillins, as chemically reactive compounds of low molecular weight, constitute typical examples of hapten allergens for humans. Penicillins become immunogenic only after covalent binding to carrier proteins and in this form frequently induced IgE-mediated allergic reactions in patients subjected to antibiotic treatment. However, our previous data strongly indicated that penicillins also form part of the epitopes contacting the antigen receptors of beta lactam-specific T cells in allergic individuals. We have therefore investigated the molecular constraints involved in the T cell immune response to penicillin G (Pen G). Designer peptides containing a DRB1*0401-binding motif and covalently modified with Pen G via a lysine epsilon-amino group were found to induce proliferation of Pen G-specific T cell clones. A precise positioning of the hapten molecule on the peptide backbone was required for optimal T cell recognition. Furthermore, we extended these observations from our designer peptides to show that a peptide sequence derived from a natural DRB1*1101-binding peptide modified in vitro with Pen G, also acquired antigenic properties. Our data for the first time provide insight into the manner in which allergenic haptens are recognized by human T cells involved in allergic reactions to drugs and suggest possible mechanisms leading to the onset of these adverse immune responses.

Carrier Proteins↗
PubMed1997

Wound healing around and within saphenous vein bypass grafts.

BACKGROUND: Myofibroblasts are a prominent cell type in wound healing. The goal of this study was to examine the extent to which myofibroblasts contribute to structural changes in saphenous vein bypass grafts. METHODS AND RESULTS: Control veins and reversed saphenous vein bypass conduits of porcine carotid arteries were examined 2 to 4, 7 to 14, and 30 to 90 days after surgery with immunohistochemical markers of cellular proliferation (proliferating cell nuclear antigen), cytoskeletal protein production (alpha-smooth muscle actin and desmin), and histochemistry (Verhoeff's stain). Control veins demonstrated an extremely low level of cellular proliferation and no evidence of myofibroblasts in the adventitia, media, or intima. After bypass grafting, cellular proliferation was followed by myofibroblast formation, which occurred in the perivascular area and within the media. This was evidenced by a dense, but transient, expression of alpha-smooth muscle actin and a variable expression of desmin at 1 to 2 weeks, and with a significant increase in collagenous tissue by 1 to 3 months. Major cytoskeletal protein changes also occurred in the intima, with the appearance of alpha-smooth muscle actin positive cells at 7 to 14 days. alpha-Smooth muscle actin was still present in the neointima at 1 to 3 months, which is compatible with a persistent myofibroblast formation. CONCLUSION: Myofibroblast formation occurs around and within saphenous veins after bypass grafting. This phenomenon is associated with significant remodeling of the vein grafts. The histologic changes are strikingly similar to events that occur during wound healing and may have implications for the development of neointimal hyperplasia and late vein graft disease.

Animals↗
PubMed1997

[CT quantification of pleuropulmonary lesions in severe thoracic trauma].

PURPOSE: Computed quantification of the extent of pleuropulmonary trauma by CT and comparison with conventional chest x-ray--Impact on therapy and correlation with mechanical ventilation support and clinical outcome. METHOD: In a prospective trial, 50 patients with clinically suspicious blunt chest trauma were evaluated using CT and conventional chest x-ray. The computed quantification of ventilated lung provided by CT volumetry was correlated with the consecutive artificial respiration parameters and the clinical outcome. RESULTS: We found a high correlation between CT volumetry and artificial ventilation concerning maximal pressures and inspiratory oxygen concentration (FiO2, Goris-Score) (r = 0.89, Pearson). The graduation of thoracic trauma correlated highly with the duration of mechanical ventilation (r = 0.98, Pearson). Especially with regard to atelectases and lung contusions CT is superior compared to conventional chest x-ray; only 32% and 43%, respectively, were identified by conventional chest x-ray. CONCLUSION: CT allows rapid classification and quantification of pulmonary lesions after thoracic trauma and provides higher sensitivity and reliability. Because of the great correlation with the extent of artificial respiration in respect of duration and pressure, prognosis of the individual patient, as well as a differential therapy, appear possible.

Adolescent↗
PubMed1997

[Heart rate variability in patients with sleep associated breathing disorders].

The increased mortality among patients with obstructive sleep apnoea syndrome has been explained in part by the increased incidence of pulmonary hypertension and coronary artery disease (CAD). A decreased heart rate variability has been shown to be associated with an increased mortality as well. We therefore screened 53 patients for sleep-related breathing disorders (SRBD) and heart rate variability (HRV) during the sleeping period. Standard time domain parameters were compared in a univariate multifactorial model for patients with an oxygen desaturation index (ODI) of more or less than 5 including the factors CAD, diabetes and beta-blocker use. The percentage of differences between RR-intervals that differ more than 50 ms (pNN > 50: 9.0 +/- 11.1% vs 19.2 +/- 22.2%; p < 0.05) as well as the root mean square of these differences (rMSSD: 38.0 +/- 29.0 msec vs 59.2 +/- 51.5 msec; p < 0.05) were significantly decreased in patients with SRBD. These results favour HRV for inclusion in future risk stratification models in patients with sleep-related breathing disorders.

Adult↗
PubMed1996

Value of routine microbial investigation in community-acquired pneumonia treated in a tertiary care center.

The study was conducted at a tertiary care and teaching hospital with about 200 beds for internal medicine. The objective was to determine the diagnostic yield and value in directing antibiotic therapy of a routine microbial approach in patients with community-acquired pneumonia referred to a tertiary care center. We studied 93 episodes in a retrospective study. 69/93 (74%) cases were treated with at least one empirical antibiotic therapy prior to admission. Microbial investigation was performed in 83/93 cases (89%). An etiological agent was established in 19/83 (23%) cases including 7/50 (14%) by blood culture and 12/52 (23%) by serology. Bronchoscopy with 18 protected specimen brush and 20 bronchoalveolar lavage examinations was definitely diagnostic in only 1/25 (4%) cases, and this case was also identified by blood culture. 5/25 (20%) were probably diagnostic. Three pathogens, Streptococcus pneumoniae, Mycoplasma pneumoniae and Legionella pneumophila, accounted for 15/19 (79%) of the identified agents. The diagnostic results directed a change in antibiotic therapy in 6/19 (32%) of cases with definitely proven pathogens. 4/19 (21%) of cases would have been treated with an inappropriate regimen without diagnostic results. The diagnostic yield of routine microbial investigation in pretreated patients is low. The routine approach reveals its limited value especially in patients with severe courses. The role of bronchoscopy remains to be defined for patients with severe (and pretreated) community-acquired pneumonia.

Adolescent↗
PubMed1996

[Community-acquired pneumonia requiring inpatient treatment: outcome and prognostic rule].

OBJECTIVE: Mortality in community-acquired pneumonia (CAP) may be reduced by early identification of patients requiring intensive care treatment. The purpose of the study was to determine prognostic factors of outcome in patients with CAP in order to establish a clinically applicable discriminant rule. METHODS: 93 episodes of 92 patients with CAP were reviewed with regard to epidemiological, clinical, laboratory and microbiologic data. The prognostic analysis included a univariate as well as a multivariate approach in order to identify parameters correlated with death using the Cox regression hazard function in a backward stepwise selection model. The three parameters found to contribute most to the significance of the model were used in a discriminant rule for classification of outcome. RESULTS: The parameters found to be significantly different between survivors and non-survivors were heart rate, systolic, diastolic as well as mean blood pressures, leucocyte count, percentage of laymphocytes, and LDH values. The multivariate analysis revealed that heart rate, systolic arterial pressure, and LDH serum levels were associated best with lethal outcome (overall significance of the model p < 0.005). A prognostic rule composed of the variables heart rate > or = 90 beats/min, systolic arterial blood pressure < or = 80 mmHg and LDH > or = 260 U/l achieved a sensitivity of 77%, a specificity of 75% and positive and negative predictive values of 42% and 93%, respectively. It was associated with a 6-fold increased risk of lethal outcome. CONCLUSIONS: Heart rate, systolic blood pressure, and LDH values were associated best with death in a multivariate analysis. A discriminant rule consisting of these three variables achieved favourable classification results. The rule qualifies for further prospective validation and may prove useful in the management of hospital treated CAP.

Aged↗
PubMed1995

[Richter hernia in trocar site after laparoscopic herniotomy].

A case of an incarcerated Richter's hernia in a 12-mm trocar site is presented. A 72 year old man underwent laparoscopic herniorrhapy because of a recurrent inguinal hernia. On the sixth postoperative day he developed abdominal pain, nausea, vomiting and abdominal distension. Plain abdominal X-ray showed bowel obstruction. Computed tomography with oral contrast showed herniation of small bowel above the fascia. The patient was immediately reoperated, the intestine was reduced, and the fascial defect at the trocar site closed. Three days later he underwent surgery again due to a small perforation of the small bowel and a persistent fascial defect. The patient had an uneventful postoperative course. Herniation through a trocar site is a rare complication-incarceration extremely rare. We recommend that all fascial defects of 10 mm or more are closed sufficiently.

Aged↗
PubMed1995

[Nodular pulmonary opacities caused by a severe suppurative bronchitis and bronchiectases].

HISTORY AND CLINICAL FINDINGS: A 67-year-old man with chronic obstructive pulmonary disease (COPD) for many years and a heavy smoker was hospitalized because of increasing dyspnoea and moderately productive cough. His general condition was clearly impaired. He was markedly cyanotic, he had a barrel-shaped chest, and there were wheezing rhonchi throughout the lung. Body temperature was 37.8 degrees C. He had mild ankle oedema. The preliminary diagnosis was exacerbation of the COPD with global respiratory failure. TESTS: There was severe hypoxaemia (pO2 48 mm Hg) with hypercapnia (pCO2 46 mm Hg). Vital capacity was reduced to 1.81, one-second forced expiratory volume 0.91. Chest radiograph revealed multiple nodular opacities, such as seen in bronchial carcinoma with metastases. But computed tomography showed fluid-filled bronchi. Bronchoscopy demonstrated large amounts of dirty-white, sticky secretions as high up as the trachea, confirming the preliminary diagnosis. Klebsiella oxytoca and haemophilus influenzae were cultured from the secretions. TREATMENT AND COURSE: Immediate administration of amoxycillin and clavulanic acid (2.2 g daily) quickly led to clinical improvement. Chest x-ray was normalized after 10 days. But long-term oxygen treatment was instituted because of persisting resting hypoxaemia (pO2 46 mm Hg), after which he was discharged free of dyspnoea. CONCLUSION: To clarify nodular pulmonary opacities in a chest radiograph computed tomography should be performed before bronchoscopy.

Aged↗
PubMed1995

Long-term flap tracheostomy in a pediatric animal model.

OBJECTIVE: To investigate the short- and long-term complications of pediatric tracheostomy, emphasizing posttracheostomy tracheal stenosis in an animal model. DESIGN: Twenty-five New Zealand white rabbits were randomly assigned to three groups: flap tracheostomy, traditional vertical tracheostomy, and control. Interactive image analysis was used to compare the tracheal cross-section area and circumference between groups 16 weeks after surgery. The incidence of peristomal infections and accidental decannulations was also compared. RESULTS: The vertical tracheostomy group had a smaller circumference (P = .01) and smaller cross-sectional area (P = .006) than the control or flap tracheostomy groups. A 30% decrease in tracheal cross-sectional area occurred in the vertical tracheostomy group. The flap tracheostomy group had fewer problems with accidental decannulation and peristomal infection compared with the vertical tracheostomy group. CONCLUSIONS: We found no significant risk of tracheal stenosis or adverse effects on tracheal growth for the flap tracheostomy in a developing animal model. This tracheostomy technique may be useful in the management of pediatric patients who require long-term bypass of the upper airway.

Animals↗
PubMed1995

Liver transplantation for hepatic arteriovenous malformation in hereditary haemorrhagic telangiectasia.

Symptomatic hepatic involvement is a rare complication of hereditary hemorrhagic telangiectasia and most commonly consists of fibrosis or cirrhosis. We describe a 33-year-old woman in whom multiple hepatic arteriovenous malformations led to high output cardiac failure and liver failure due to biliary necrosis with refractory biliary sepsis, requiring orthotopic liver transplantation. Hepatic arteriovenous malformations were the first manifestation of the disease and a similar asymptomatic hepatic tumour was subsequently detected in her 60-year-old father who also had the classical cutaneous stigmata of the syndrome. Unrecognised genetic factors may determine the clinical spectrum of hereditary haemorrhagic telangiectasia including the hepatic manifestations.

Adult↗
PubMed1995

The "low intensity treadmill exercise" protocol for appropriate rate adaptive programming of minute ventilation controlled pacemakers.

The objective of rate adaptive pacemakers that measure minute ventilation by transthoracic impedance is to simulate the physiological relationship of the sensed signal to the sinus node response during exercise, thus achieving an appropriate matching of heart rate with patient effort. The purpose of this study was to determine the physiological relationship between heart rate and minute ventilation (HR/VE) during peak exercise testing in order to develop a database for appropriate rate adaptive slope programming of minute ventilation controlled pacemakers. Due to several clinical limitations of peak exercise testing, it was additionally determined whether the 35-watt "low intensity treadmill exercise" (LITE) protocol can be used as a substitute for peak exercise test using the "ramping incremental treadmill exercise" (RITE) protocol in order to assess the correct HR/VE slope below the anaerobic threshold. The stress tests were performed on a treadmill with the collection of breath-by-breath gas exchange. Linear regression analysis was used to determine the HR/VE slope below and above the anaerobic threshold and during the early, dynamic phase of low intensity exercise with the RITE and LITE protocols, respectively. The results of this testing in 41 healthy subjects demonstrated that the HR/VE relationship throughout treadmill exercise using the RITE protocol was not linear but curvilinear in nature, with a steeper HR/VE slope of 1.54 +/- 0.51 below versus 1.15 +/- 0.37 above the anaerobic threshold (P < 0.005). The HR/VE slope determined during the early, dynamic phase of the LITE protocol (1.58 +/- 0.88) did not differ from the HR/VE slope from rest to anaerobic threshold obtained using the peak exercise RITE test (1.54 +/- 0.51; P = 0.79). Rate adaptive pacing should simulate the curvilinear relationship between heart rate and minute ventilation from rest to peak exercise. The HR/VE slope determined during the early, dynamic phase of low intensity exercise represents the HR/VE slope derived from the RITE protocol below the anaerobic threshold. According to the peak exercise database, the slope above anaerobic threshold can easily be calculated as a percentage of the slope below the anaerobic threshold. The LITE protocol can, therefore, be effectively performed as a substitute for peak exercise stress tests to determine the correct pacemaker rate response factor in order to obtain a physiological heart rate to minute ventilation relationship for the appropriate matching of paced heart rate with patient effort.

Anaerobic Threshold↗
PubMed1995

Nursing interventions for spiritual care: preferences of the community-based elderly.

This descriptive correlational study examined the relationships between the three concepts of core spiritual experience, spiritual perspective, and self-transcendence, as well as the spiritual-care nursing interventions preferred by a convenience sample of 50 community-based older adults. Results of single-session interviews indicated significant positive correlations among the three concepts. Spiritual interventions preferred by older adults were those interventions focusing on the therapeutic communication skills of the nurse and the nurse's attitude and approach toward clients. Overall, older adults who believed in a Higher Power and whose beliefs were prominent in their lifestyle rated spiritual nursing interventions as more important than did older adults who did not hold strong beliefs in a Higher Power and whose spiritual beliefs were not prominent in their lifestyle. Findings give direction for providing spiritual nursing care to older adults.

Aged↗
PubMed1995

Prognostic analysis and predictive rule for outcome of hospital-treated community-acquired pneumonia.

In community-acquired pneumonia (CAP) mortality may be reduced by early identification of patients requiring intensive care treatment. The purpose of this study was to determine prognostic factors of outcome in patients with CAP in order to establish a clinically applicable discriminant rule. Ninety three episodes of CAP in 92 patients were retrospectively reviewed with regard to epidemiological, clinical, laboratory and microbiological data. The prognostic analysis included a univariate as well as a multivariate approach, in order to identify parameters associated with death using the Cox regression hazard function in a backward stepwise selection model. The three parameters found to contribute most to the significance of the model were used in a discriminant rule for classification of outcome. The parameters found to be significantly different between survivors and non-survivors were heart rate, systolic and diastolic as well as mean blood pressures, leucocyte count, percentage of lymphocytes, and lactate dehydrogenase (LDH) values. The multivariate analysis revealed that heart rate, systolic arterial pressure, and LDH serum levels were most closely associated with fatal outcome. A prognostic rule composed of the variables heart rate > or = 90 beats.min-1, systolic arterial blood pressure < or = 80 mmHg, and LDH > or = 260 U.l-1 achieved a sensitivity of 77%, a specificity of 75%, and positive and negative predictive values of 42 and 93%, respectively. It was associated with a six fold increased risk of fatal outcome. In conclusion, heart rate, systolic blood pressure, and LDH values were most closely associated with death in a multivariate analysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗
PubMed1995

An analysis of desynchronization between the spontaneously breathing patient and ventilator during inspiratory pressure support.

It is common practice to convert patients with acute respiratory insufficiency (ARI) from controlled mechanical ventilation to some form of assisted spontaneous breathing as early as possible. A widely used mode of assisted spontaneous breathing is patient-triggered inspiratory pressure support (IPS). We investigated 11 patients with ARI during weaning from mechanical ventilation using IPS and found that in 9 of these patients, desynchronization between patient and ventilator occurred, ie, that the ventilator did not detect and support all the patients' breathing efforts. Five of these 9 patients displayed severe desynchronization lasting at least 5 min and with less than half of all breathing efforts being supported by the ventilator. We present the analysis of gas flow, volume, esophageal pressure, airway pressure, and tracheal pressure of 1 patient with ARI displaying desynchronization under IPS. Our results imply that desynchronization can occur due to the following: (1) inspiratory response delays caused by the inspiratory triggering mechanisms and the demand flow characteristics of the ventilator; (2) a mismatch between the patient's completion of the inspiration effort and the ventilator's criterion for terminating pressure support; and (3) restriction of expiration due to resistance from patient's airways, endotracheal tube, and expiratory valve. From our analysis, we have made proposals for reducing desynchronization in clinical practice.

Aged↗
PubMed1995

[The MRI in pre- and postnatal diagnosis of congenital sacrococcygeal teratoma].

INTRODUCTION: The main tasks of imaging methods on the evaluation of relatively rare and potentially malignant connatal sacrococcygeal teratomas (SCT) are to depict the extent, structure and relationship to surrounding systems. METHODS: Two cases with SCT were studied with pre- and postnatal MRI and findings were compared with the ultrasound and clinical data. RESULTS: Before delivery, MRI permits depiction of the size and structure of teratomas and the integrity of the serum. After delivery, evaluation of the rectum, urinary tract and levator muscles is important to facilitate surgical reconstruction.

Adult↗