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Biomedical subjects

G Friehs

Publications and source records attributed to G Friehs.

At least 19 recordsLinked to original sources
PubMed1994

8-12 Hz rhythmic oscillations in human motor cortex during two-dimensional arm movements: evidence for representation of kinematic parameters.

Direct cortical recordings were taken from 12 patients with implanted subdural electrode arrays during performance of a 2-dimensional, multi-joint, visually guided arm movement task. Task-related changes in the amplitude of the motor cortex 8-12 Hz surface local field oscillations were evaluated for the encoding of direction and amplitude of movement in the 6 patients in whom no epileptogenic or ECoG background abnormalities were detected over the motor-sensory cortical areas under the recording electrode array. The topography, time of onset and duration of these responses were evaluated in the context of motor cortex somatotopy, as defined by cortical stimulation delivered through the electrode array. Multi-joint arm movements were accompanied by a decrease in the power of the 8-12 Hz frequency components of the ECoG signal. These power changes were spatially distributed over the upper extremity, motor-sensory representation. Movement amplitude influenced the magnitude, duration, and extent of the spatial distribution of ECoG power changes in the 8-12 Hz band. These effects occurred predominantly over cortical areas corresponding to the upper extremity motor-sensory representations. Direction of movement had a weaker influence on the 8-12 Hz frequency components of the ECoG over the upper extremity motor-sensory representations, but influenced the patterns of 8-12 Hz ECoG response on adjacent cortical regions. These results show that the amplitude of surface electrical oscillations generated over the rolandic cortex are correlated with the kinematics of multi-joint arm movements. These changes in the ECoG signal appear to reflect shifts in the functional state of neuronal ensembles involved in the initiation and execution of motor tasks.

Adult↗
PubMed1992

Open-window thoracostomy in pleural empyema.

Open-window thoracostomy (OWT) was performed in 21 cases of empyema. The indications were postpneumonectomy empyema with (n = 6) or without (n = 1) fistula, early recurrent empyema after decortication (n = 6), chronical empyema in ill elderly patients with (n = 5) or without fistula (n = 2), and total unilateral lung gangrene with a large fistula of the main bronchus after radiotherapy and chemotherapy (n = 1). All cases presented with severe sepsis, eight of them with acute septic shock, and six with signs of multiorgan failure. Three to five ribs were resected, the muscles and skin were sutured to the ribs confining the window located at the lowest point of the empyema cavity, while the intercostal muscles of the resected ribs were used to close fistulae. The cavity was packed with dressings every day. In all cases, the sepsis subsided immediately after OWT. With the exception of one patient with postpneumonectomy empyema, who died of contralateral pneumonia on day 36, no surgery-related complications were seen. Four further patients died of unrelated causes 2, 4, 5, and 7 months, respectively, after OWT. In one of them, the OWT had been closed. Up to this time, obliteration and closure of the cavity has been carried out in 7 cases by using thoracoplasty (n = 2) or predicted muscle flaps (n = 5) either in the early course or after a delay of 11 to 23 months, with fair functional and cosmetic results. In one further case, operative closure has been planned. In seven of the eight remaining patients, four of whom declined further operations, the cavities closed spontaneously, despite their initial size after intervals of between 11 and 21 months.

Adult↗
PubMed1992

Surgical and non-surgical treatment of cancer of the oesophagus and the oesophagogastric junction: results of 200 consecutive cases.

200 consecutive, unselected patients with cancer of the oesophagus or the oesophagogastric junction (89 squamous, 110 adenocarcinoma or undifferentiated, 1 oat cell) between 1984 and 1987 were reviewed. Resection with postoperative adjuvant irradiation in the cases of squamous cell cancer, was carried out in 51 patients and non-surgical treatment [57 combined dilation and Nd-YAG-laser, 64 iridium 192 high-dose rate brachytherapy with or without 60 Gy external beam irradiation (EBR); 28 endoprostheses] was performed in the remaining 149 patients. The overall 5 year-survival rate was 9.2% (resections: 17.9%, non-resected: 5.2%). Resected nodal negative T1 or T2 patients had the best prognosis (45.8% 5-year survival). The median survival following dilation and laser was 3.4 months for all T-stages. Endoprostheses yielded a median survival of 1.7 months. Intracavitary brachytherapy gave the best palliative result with 6.5 months median survival, whereby only T1 and T2 patients benefitted from additional EBR. Histological subtype, age, sex or tumour localization did not influence survival. Multivariate analysis showed that in M0 patients the choice of treatment had a significant impact on prognosis.

Adenocarcinoma↗
PubMed1992

Intracardiac malpositioning of a sternoclavicular fixation wire.

A case of intracardiac malpositioning of a sternoclavicular Kirschner pin is reported. After an uneventful closed wire-fixation of sternoclavicular subluxation and a normal postanesthetic recovery, a 17-year-old male patient developed opacification of the right hemithorax and signs of internal bleeding. The lateral chest roentgenogram showed one fixation wire protruding deeply into the anterior mediastinum. Sternotomy showed a large pericardial tear communicating with the right pleural cavity and a puncture hole of the right auricle that had caused a blood loss of 3 L into the pleural space. Although the surgical repair was uneventful, the patient eventually died as a sequelae to prolonged cerebral hypoxemia.

Adolescent↗
PubMed1992

IgG-anticardiolipin-antibodies are markers for cerebral and peripheral artery disease.

Anticardiolipin-antibodies are antibodies to phospholipids which were first detected in patients with arterial thrombosis and lupus erythematosus. In this prospective study, IgG- and IgM-anticardiolipin-antibodies were determined in patients with cerebral and/or peripheral artery disease but without autoimmune disorders. 123 randomly selected patients (88 males, 35 females; mean: 65 +/- 10, range: 41-85 years) were included and divided into four groups: 18 patients with isolated cerebrovascular disease (group A), 35 patients with peripheral artery disease only (group B), 35 patients suffering from cerebral and peripheral artery disease (group C) and 35 patients as controls (group D). In family history, cholesterol, blood sugar and prothrombin time the four patient groups did not differ significantly, whereas patients of group B and C were more often smokers than those in groups A and D. However, IgG-anticardiolipin-antibody-levels were significantly elevated in patients with cerebral and peripheral artery disease compared to controls (p less than 0.01). The highest values were seen in group C where patients suffered from cerebral and peripheral artery disease (n.s.). On the other hand, IgM-anticardiolipin-antibody-levels did not show any differences in the four groups. Furthermore, there was no correlation between vascular risk factors and/or laboratory findings with IgG- and IgM-antibody-levels. Thus, elevated IgG-anticardiolipin-antibodies appear to be independent markers for severe cerebral and peripheral artery disease and should be determined in patients at increased risk.

Adult↗
PubMed1991

Total unilateral lung gangrene in Hodgkin's disease: treatment by thoracostomy.

Total gangrene of the left lung developed in a 30-year-old male patient with a pulmonary recurrence of Hodgkin's disease after mediastinal irradiation and chemotherapy. Clinically, tension pyopneumothorax and severe septic shock were present. Surgical repair was done by thoracostomy, resecting three ribs. A 2 x 0.5-cm hole in the necrotic wall of the left main bronchus was covered with an intercostal muscle bundle. The necrotic pleural surfaces were treated openly by daily change of dressings. The patient recovered satisfactorily and underwent four further courses of chemotherapy without any complications.

Adult↗
PubMed1991

The importance of early detection and therapy of reexpansion pulmonary edema.

Three cases are reported of unilateral pulmonary edema, two following rapid reexpansion after prolonged tension pneumothorax, with total collapse of the right lung and one after reexpanded atelectasis following left intrabronchial obstruction. In all cases decrease of blood pressure and tachycardia not responding to intravenous fluid substitution were already present within the first 15 min after chest drainage or after removal of the intrabronchial obstruction. The preexistent dyspnea failed to improve. A cloudy opacity of the reexpanded lung was found immediately after drainage in 2 cases. After immediate application of a continuous positive airway pressure mask no more extensive therapy was necessary in one patient. The two others in whom treatment was begun with more than 1 hour delay required artificial ventilation and adrenergics for 2 and 4 days, respectively.

Adult↗
PubMed1990

Electroencephalographic and evoked potential monitoring in the hyperbaric environment.

The purpose of this study was to investigate brain bioelectrical activity during hyperbaric oxygenation by continuous and simultaneous monitoring of electroencephalographic and bimodal (auditory, somatosensory) evoked potentials. Multivariable recordings (electroencephalogram, brainstem auditory evoked potentials, early somatosensory evoked potentials, heart rate, heart rate variability, and transcutaneous partial pressure of oxygen) were measured with a new technique in 12 healthy male volunteers 26 to 52 years old (mean +/- SD, 35.9 +/- 9.5 years). Recordings were obtained while the subjects breathed (1) air at normal atmospheric pressure, (2) 100% oxygen at normal atmospheric pressure, (3) air at 2 atm (10 meters sea water [msw]), and (4) 100% oxygen at 2 atm (10 msw). Spontaneous brain electrical activity, somatosensory evoked potentials, and heart rate variability were not significantly affected during hyperbaric oxygenation, whereas the heart rate showed a significant decrease (paired t test, P less than 0.05). Alterations in brainstem auditory evoked potentials were seen under hyperbaric conditions and did not reach statistical significance (increase of the I-V interpeak latency by paired t test; P less than 0.2). All subjects showed insignificant increases in dominant alpha frequency and decreases in delta frequency under hyperbaric situations.

Adult↗
PubMed1990

Intraoperative radiation therapy combined with external irradiation in nonresectable non-small-cell lung cancer: preliminary report.

Twenty-one patients with nonresectable non-small-cell lung cancer (15 squamous-cell, 4 adeno, 2 large-cell; T1-T3, N0-N2, all M0) underwent lymph node dissection and intraoperative irradiation of the tumor (IORT) with doses between 10 and 20 Gy (energies: 7 to 20 MeV electron beam). Postoperatively, 46-56 Gy external beam irradiation (8 or 23 MeV photon beam) were delivered to the mediastinum and 46 Gy to the tumor bearing area. Fifteen patients were available for follow-up investigations. The CT-scan tumor volumetry 4 weeks postoperatively showed a significant overall decrease (Wilcoxon test: p less than 0.05) with eight minor responses (MR) (tumor regressions between 4 and 45%) and six partial responses (PR) (between 50 and 84%). One case was not evaluable. A second volumetry after external irradiation was done in 14 patients, 18 weeks after IORT, showing 3 complete responses, 10 partial responses (62 to 84%), and 1 minor response (28%). The recent volumetries (10 patients) between 4.5 and 16.5 months after IORT showed 7 complete responses and 3 partial responses (63 to 94%). One patient died from intrabronchial hemorrhage at 7 weeks. Three others died from unrelated causes, 6, 12 and 14 months, respectively, after IORT and in one further case the cause of death at 15 months was local tumor regrowth. Within the median time elapsed since IORT (12 months) only this one case of local regrowth and one further case of distant spread were observed.

Aged↗
PubMed1990

Pitfalls in intraoperative frozen section histology of mediastinal neoplasms.

We evaluated the reliability of intraoperative frozen section histology in 149 mediastinal tumours of which 106 lesions were localized in the anterior, 18 in the central and 25 in the posterior mediastinum. Gross non-resectability was ruled out by preoperative imaging. No preoperative cytological or histological diagnosis was obtained in any case. At thoracotomy, 3 biopsies from 3 different sites of the tumour were processed for frozen section as well as for paraffin histology and immunohistochemistry. In 67 of 73 benign lesions (91%), the intraoperative diagnosis was correct, 5 cases could not be classified by frozen section and 1 case had to be revised. Only 28 of 76 malignant lesions (36.8%) were diagnosed correctly by intraoperative frozen section. In 27 cases (35.5%), no intraoperative classification was possible and in 21 patients (27.6%), the diagnosis was wrong with the consequence of surgical overtreatment for lymphoma misinterpreted as thymic cancer in 3 cases. In patients in whom preoperative investigations suggest borderline resectability, a staged procedure to obtain histology prior to definitive surgery could prevent overtreatment.

Adolescent↗
PubMed1990

[A therapeutic concept for the treatment of inoperable esophageal carcinoma].

From 1/87 to 12/88, 20 patients with anatomically or functionally inoperable carcinomas of the esophagus (cT1-3/N0-2/M0-1) were treated by endoluminal Ir-192 HDR brachytherapy (1-3 sessions, each 5-7 Gy) and percutaneous irradiation (50-70 Gy/2 Gy). In 10 cases a bouginage or combined dilatation and retrograde Nd-Yag-laser debulking was done before irradiation. The response of the treatment was documented by endoscopy (degree of stenoses) and symptoms (dysphagia score according to De Meester). In 95% of all cases the degree of stenoses was diminished and an improvement of dysphagia was found in 100%. The mean duration of oral uptake of properly chewed food could be prolonged to 308 days.

Brachytherapy↗
PubMed1990

[Intraoperative radiotherapy (IORT) at the Graz University Clinics: development and dosimetry of an applicator system].

The use of high energy electron beams for intraoperative radiotherapy necessitates special technical adjustments of the conventional megavolt equipment. At the University Clinic of Radiology, Division of Radiotherapy in Graz, an applicator system for electron energies up to 20 MeV and cone diameters up to 14 cm was developed. A self modified commercial operating table was used instead of the treatment couch to guarantee optimum mobility for the docking maneuver. The technical set-up of this adaptor system as well as the dosimetric considerations and calculations will be presented in detail.

Austria↗
PubMed1990

[Intraoperative radiotherapy (IORT) at the Graz University Clinics: results of a pilot study on non-small cell lung carcinoma].

A pilot study was undertaken during which 15 patients with non-small cell pulmonary carcinomas were exposed to an intraoperative irradiation; twelve out of them were submitted to an additional percutaneous photon therapy. The criteria used to select these patients were functional inoperability, exclusion of remote metastases, and a Karnofsky index greater than 70. Central and peripheral tumors of the stages T1-3, N0-2 were included into the study after histological confirmation of the diagnosis. The local regression rate of the primary tumor can be assessed quite well despite the short follow-up time of 4.5 to 16 months (10 months on an average) which does not yet allow to make a conclusion as to a prolongation of the disease-free survival time. Already two months after the end of external irradiation, a complete remission (CR) was seen in three patients (25%), a partial remission (PR) in seven patients (67%), and a minor remission (MR) in one patient. In the course of further follow-up, the number of complete remissions increased to six (50%). We are encouraged by the small morbidity and a therapeutic response higher than average to continue with this therapy method in patients who, for the time being, are still selected according to strict criteria.

Aged↗
PubMed1989

Reinforced staple line in severely emphysematous lungs.

In severely emphysematous or otherwise destroyed lung parenchyma, staples often cut through, which causes prolonged postoperative air leakage. A mechanical suture line reinforced by a polydioxanone ribbon is a simple, safe, and effective method for closure of air leaks, resection, or biopsy in such cases.

Humans↗
PubMed1988

[Value of 24-hour long-term pH monitoring with computer-assisted evaluation in gastroesophageal reflux disease].

There are a variety of diagnostic procedures in use to confirm the diagnosis gastroesophageal reflux (reflux-esophagitis, GER). The accuracy of the described methods are different. Computerized 24 hours long term pH monitoring has established to be a very reliable procedure in the diagnosis of GER. From 1984 to 1986 134 patients underwent 24 hours pH monitoring besides X-ray, scintiscan, and esophageal-manometry. The combination of manometry and 24 hours pH monitoring has given the biggest insight into the pathogenesis of GER and seems to be undispensable for specific therapeutic procedures.

Electrodes↗
PubMed1988

Solitary coin lesion in patients with malignant melanoma: an indication for thoracotomy?

In five patients solitary pulmonary lesions were detected radiographically during routine follow up after malignant melanoma. Surgical removal was done in each case under the tentative diagnosis of metastases. Histologically, two lesions turned out as benign chondroma, one as organized pulmonary infarction and one as bronchogenic carcinoma. Only in one patient was a melanoma metastasis present. The findings underline the usefulness also in malignant melanoma of a surgical approach in suspected solitary pulmonary metastases.

Adult↗
PubMed1988

Pulmonary exchange of solutes during experimental lung lavage in pigs.

Unilateral continuous lung lavage in a nonregenerating system (3,000 ml isotonic cristalloid) was done in 12 pigs for 270 min. The concentration of substances in serum and fluid was measured. Half-time (t1/2) of exchange and permeability constants (P) were determined. In the fluid Na+ decreased significantly (t1/2 = 107 min, P = 7.8 x 10(-7]. Urea increased significantly, reaching serum level after 270 min (t1/2 = 109.1 min, P = 6.18 x 10(-6]. Ca2+ (t1/2 = 36.7 min, P = 4.1 x 10(-7] PO4 = (t1/2 = 173.3 min, P = 1.1 x 10(-7], and creatinine (t1/2 = 55.2 min, P = 6.2 x 10(-7] also increased markedly but did not reach serum level. The adjustment to serum concentration may be prevented by interaction between diffusion, active transport or Donnan's equilibria. K+ increased almost linearly, documented by the long half-time (t1/2 = 7,835.2 min, P = 7.7 x 10(-7] and did not reach serum level. The calculated limit value was higher than the serum level. Active transport systems or influx of K+ from cellular compartments rather than from the serum might be involved in its linear kinetics. Total protein (t1/2 = 61.5 min, P = 2.06 x 10(-9] and albumin (t1/2 = 58.8 min, P = 1.7 x 10(-9] increased initially but levelled far below the serum value. The low P indicates a lack of significant permeation. Initial increase may be due to washout of the epithelial lining fluid compartment. There was minimal transfer of lavage fluid into the organism (10-20 ml/30 min). Serum concentrations were not affected by the lavage.

Animals↗