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Biomedical subjects

T Bauer

Publications and source records attributed to T Bauer.

At least 73 records · Page 4Linked to original sources
PubMed1999

High doses of vitamin E in the treatment of disorders of the central nervous system in the aged.

Oxidative stress is a putative factor in the pathogenesis of many human disorders of the central nervous system. Therefore, antioxidants such as vitamin E have become attractive as therapeutic agents in the treatment of several diseases. In addition, vitamin E seems to play a specific role in the nervous system. As a result, vitamin E has been used in pharmacologic doses in the treatment of disorders such as Parkinson disease, Alzheimer disease, and tardive dyskinesia. One investigation showed that the use of 2000 IU all-rac-alpha-tocopheryl acetate is beneficial in the treatment of Alzheimer disease. Similar doses of vitamin E, however, were not beneficial for delaying the progression of Parkinson disease. In other studies, dosages >/=400 IU vitamin E/d were found to be beneficial in the treatment of tardive dyskinesia, although this finding was not confirmed in a larger cooperative study conducted by the Veterans Administration. Even though the efficacy of vitamin E in the management of cardiovascular disease has been shown, the potential role of vitamin E in the treatment of cerebrovascular disease remains essentially unknown. The experience from 2 large clinical trials involving the oral intake of 2000 IU vitamin E/d suggests that vitamin E is relatively safe at this dosage for periods <2 y. However, the safety and efficacy of supplemental vitamin E over periods of many years in the prevention of neurologic diseases has not been adequately explored.

Aged↗
PubMed1999

Free flap reconstruction of the foot.

Free flap reconstruction of the foot has been widely performed in the last 20 years, but choice of a free transferred substitute for the soft tissue of the particular defect remains controversial. The authors present a series of 77 free flaps to the foot performed in 68 patients during October 1976 and September 1997. Long-term follow-up ranged from 12 months to 18 years (median, 44.4 months). Seventy-three flaps were transferred successfully (95%). The indications for a specific flap depended on the localization and extension of the foot defect. In weight-bearing areas the authors favored the use of a muscle flap covered with a split-thickness skin graft; the latissimus dorsi muscle was used primarily. This study shows a lower ulceration rate in muscle flaps covered with split-thickness skin grafts than in fasciocutaneous flaps in weight-bearing areas (27% vs. 60%). In nonweight-bearing areas, fasciocutaneous flaps were the best choice. In this series, the lateral arm flap was applied most often. The authors recommend free fascial flaps (serratus fascial flap or radial forearm fascial flap) covered by split- or full-thickness skin grafts for coverage of the malleolar region as well as coverage of exposed tendons of nonweight-bearing regions. Proper tailoring of the flap and postoperative care are very important to maintain a result without ulceration, as is avoiding having the suture line cross a weight-bearing area. Tactile sensation does not seem to be essential.

Adolescent↗
PubMed1999

Functional regions of the Bacillus subtilis spore coat morphogenetic protein CotE.

The Bacillus subtilis spore is encased in a resilient, multilayered proteinaceous shell, called the coat, that protects it from the environment. A 181-amino-acid coat protein called CotE assembles into the coat early in spore formation and plays a morphogenetic role in the assembly of the coat's outer layer. We have used a series of mutant alleles of cotE to identify regions involved in outer coat protein assembly. We found that the insertion of a 10-amino-acid epitope, between amino acids 178 and 179 of CotE, reduced or prevented the assembly of several spore coat proteins, including, most likely, CotG and CotB. The removal of 9 or 23 of the C-terminal-most amino acids resulted in an unusually thin outer coat from which a larger set of spore proteins was missing. In contrast, the removal of 37 amino acids from the C terminus, as well as other alterations between amino acids 4 and 160, resulted in the absence of a detectable outer coat but did not prevent localization of CotE to the forespore. These results indicate that changes in the C-terminal 23 amino acids of CotE and in the remainder of the protein have different consequences for outer coat protein assembly.

Bacillus subtilis↗
PubMed1999

Clinical diagnosis of ventilator associated pneumonia revisited: comparative validation using immediate post-mortem lung biopsies.

BACKGROUND: A study was undertaken to assess the diagnostic value of different clinical criteria and the impact of microbiological testing on the accuracy of clinical diagnosis of suspected ventilator associated pneumonia (VAP). METHODS: Twenty five deceased mechanically ventilated patients were studied prospectively. Immediately after death, multiple bilateral lung biopsy specimens (16 specimens/patient) were obtained for histological examination and quantitative lung cultures. The presence of both histological pneumonia and positive lung cultures was used as a reference test. RESULTS: The presence of infiltrates on the chest radiograph and two of three clinical criteria (leucocytosis, purulent secretions, fever) had a sensitivity of 69% and a specificity of 75%; the corresponding numbers for the clinical pulmonary infection score (CPIS) were 77% and 42%. Non-invasive as well as invasive sampling techniques had comparable values. The combination of all techniques achieved a sensitivity of 85% and a specificity of 50%, and these values remained virtually unchanged despite the presence of previous treatment with antibiotics. When microbiological results were added to clinical criteria, adequate diagnoses originating from microbiological results which might have corrected false positive and false negative clinical judgements (n = 5) were countered by a similar proportion of inadequate diagnoses (n = 6). CONCLUSIONS: Clinical criteria had reasonable diagnostic values. CPIS was not superior to conventional clinical criteria. Non-invasive and invasive sampling techniques had diagnostic values comparable to clinical criteria. An algorithm guiding antibiotic treatment exclusively by microbiological results does not increase the overall diagnostic accuracy and carries the risk of undertreatment.

Anti-Bacterial Agents↗
PubMed1999

[Intermittent positive pressure ventilation after sternectomy].

BACKGROUND: The indication for intermittent positive pressure ventilation (IPPV) is the symptomatic hypercapnic ventilatory insufficiency. Beside the improvement of life quality and extension of life time the aim of IPPV is a reduction of the secondary effects of chronic hypoventilation in order to stabilize the symptoms. PATIENTS AND METHODS: We examined 2 patients after sternectomy because of osteomyelitis who developed a symptomatic ventilatory insufficiency together with recurrent dys- and atelectasis and pneumonia, resistant against to antibiotic treatment. After initiation of IPPV the patients turned to a clinically stable condition. The nocturnal oxygen saturation improved as well as the daytime blood gas analysis. In these patients the indication for IPPV was not only the symptomatic hypercapnic ventilatory insufficiency but also the prophylaxis of recurrent dys- and atelectasis and pneumonia. Antibiotic therapy after sternectomy is often not successful, therefore in case of recurrent infections in patients with unstable thorax the early initiation of IPPV seems to be useful.

Aged↗
PubMed1999

[Effect of acupuncture on quality of life, mouth occlusion pressures and lung function in COPD].

BACKGROUND: There are few data concerning the effect of acupuncture in patients suffering from COPD. We conducted a prospective randomized and placebo-controlled pilot study to analyze the effect of acupuncture according to the rules of traditional chinese medicine on quality of life, pulmonary function testing and inspiratory mouth occlusion pressures (MOP). PATIENTS AND METHODS: We randomised 10 patients with stable COPD to a 2-week treatment of 7 verum acupuncture or placebo acupuncture sessions. Before and after treatment we performed pulmonary function tests as well as an interview with the chronic respiratory disease questionnaire. MOP were taken on day 1, 5 and 7 before and after punction to assess function of the respiratory pump. RESULTS: Patients receiving verum acupuncture improved significantly with FEV1 and RV/TLC. There was an improvement of large magnitude in quality of life and a trend of lower demand of the respiratory pump. In the placebo group we saw only a slight improvement of quality of life, a deterioration of lung function parameters and a trend of higher demand of the respiratory pump. CONCLUSION: Although the small number of subjects allows no further conclusions this pilot study proves feasibility of acupuncture in COPD and shows that acupuncture is worthy for further investigation in patients suffering from COPD.

Acupuncture Therapy↗
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

Network migration of ethnic Germans.

"This study has argued that network migration is central to actual migratory movements, which suggests that its determinants should be carefully investigated. The analysis demonstrates that the network behavior of ethnic Germans can be explained, to a large degree, by observable characteristics. Two crucial variables were investigated, namely the connections to friends from the country of origin and the settlement close to relatives and friends. East Europeans, especially from Rumania, are significantly more connected to friends from the same country of origin than are East Germans. These connections strongly decline with duration of residence and presence in rural areas. Older people are more likely to settle close to friends or relatives at the time of immigration. Population density increases, education, length of stay in a reception camp, and per capita government expenditures decrease the likelihood of such a settlement."

Culture↗
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↗