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Biomedical subjects

M Freitag

Publications and source records attributed to M Freitag.

At least 55 records · Page 3Linked to original sources

[Ranking of 20 MHz sonography of malignant melanoma and pigmented lesions in routine diagnosis].

PURPOSE: Eleven dermatology clinics from all over Germany took part in our multicenter prospective study with the aim of evaluating 20 MHz sonography in the preoperative diagnosis of malignant melanomas and other pigmented skin tumours. It was to be assessed how effective sonographic measurement of thickness would compare to histology and the clinical palpation of tumour thickness and also the significance of differential diagnosis in sonography of malignant melanomas. METHOD: The prospective multicenter study proceed as follows. To the end of August 1997 264 patients with a primary malignant melanoma and 417 patients with benign skin tumours were examined via 20 MHz sonography. Two different examiners estimated the clinical thickness of the tumour by palpation. The tumour was then excised and examined for postoperative correlation with the histology sections. RESULTS: The final results showed good correlation between the histological and sonographic estimation of tumour thickness (r = 0.97). Estimation of tumour thickness by palpation showed no correlation with the histology (r = 0.59). Most of the benign (44%) and malignant tumours (38.7%) were spindle shaped. There was no significant difference between the benign and malignant tumour groups in relation to the sonographic presented shapes or echo signs. No different diagnosis could be made. CONCLUSION: The technique of high frequency sonography in relation to preoperative diagnosis of malignant melanomas has high priority. In contrast to clinical estimation of tumour thickness, sonography provided a good correlation to histology. The effectiveness of sonography with regard to the valence of the skin tumours is limited and there is no possibility of differentiating between malignant and benign tumours from the morphological face value. Hence, there is a demand for developing a 150 MHz apparatus which will be able to supply evidence regarding the valence of skin tumours.

Diagnostic Tests, Routine↗

[Bovine hemoglobin. HBOC-201 causes a reduction of the oxygen partial pressure in poststenotic skeletal muscle].

UNLABELLED: We investigated the effects of ultrapurified polymerized bovine hemoglobin (HBOC-201) on skeletal muscle tissue oxygen tension when applied before establishment of a nearly complete arterial stenosis. METHODS: Twelve foxhounds were anaesthetized IV and mechanically ventilated with 30% oxygen in air. Catheters were inserted into the right femoral artery and vein for measurements of haemodynamic parameters and blood-gas sampling. Arterial blood flow of the left popliteal artery was measured by an electromagnetic flow probe. Skeletal muscle tissue oxygen tension (tpo2) was measured in the left gastrocnemic muscle using a stepwise-driven polarographic needle probe, creating histograms from 200 single tpO2 measurements. Following isovolaemic haemodilution with Ringer's solution to a target haematocrit of 20%, the animals were randomly assigned to receive either 200 ml of predonated fresh blood (group 1) or 200 ml of HBOC-201 (MW 32,000-500,000; Hb 13 +/- 1 g-dl-1, group 2). After a 15-min stabilization period, a 95% artificial stenosis of the left popliteal artery was established. While animals of group 1 received two applications of 200 ml 6% hetastarch (HES, 200,000; 0.5), animals of group 2 received 200 ml Ringer's solution 45 and 75 min after establishment of the arterial stenosis, respectively. Variables were measured at baseline, after haemodilution and application of the respective compound, and 30, 60 and 90 min after establishment of the stenosis. RESULTS: Demographic data, muscle temperature and arterial blood gases did not differ between groups. With the exception of a higher mean pulmonary artery pressure in HBOC-201-treated animals, haemodynamics did not differ between groups. In both groups oxygen delivery and oxygen consumption of the muscle decreased in parallel to the decreasing blood flow during arterial stenosis. In contrast, oxygen extraction ratio increased after infusion of HBOC-201 and remained unchanged during stenosis (P < 0.05). In group 1, the tpO2 decreased during stenosis when compared to baseline (P < 0.001) and remained decreased after administration of HES. In contrast, administration of 200 ml of HBOC-201 before establishment of the arterial stenosis sustained the tpO2 values at nearly baseline levels during stenosis. Skeletal muscle tissue oxygen tension was higher after HBOC-201 infusion during stenosis when compared to HES infusion (P < 0.001). CONCLUSION: These data suggest that haemoglobin solutions can reach poststenotic tissues. The increased oxygen extraction after application of HBOC-201 is associated with improved skeletal muscle oxygen tension during severe arterial stenosis.

Animals↗

[Clinical and imaging aspects of gallstone ileus. Experiences with 108 individual observations].

Cases of gallstone ileus (108) were analyzed retrospectively over 30 years. Even today, when laparoscopic cholecystectomy is done, the incidence of this rare disease remains the same. History, clinical and X-ray findings are non-specific. Aerobilia was seen in 17% of the patients. Since 1992 sonography has provided an exact diagnosis in 10 of 15 cases. In the triad of known gallstone, non-specific epigastric pain with assumed small intestinal obstruction, and impossible detection of a stone in the gallbladder, there is strong suspicion of a gallstone ileus. The evidence is given if the gallstone is seen in the bowels. Intraoperatively more than one stone was found in the intestines in 20%, and cholecystoduodenal fistulas were encountered in 83%. Other fistulas are rare. There has been no significant change in mortality for 30 years.

Aged↗

[Ficus benjamina--the hidden allergen in the house].

The weeping fig, Ficus benjamina (Fb), is a relatively common indoor allergen. Many cases of perennial allergic rhinoconjunctivitis and allergic asthma caused by Fb hypersensitivity are not detected. These patients typically have proven sensitization to housedust mites and do not improve after avoidance of exposure (encasing) and specific immunotherapy. The number of Fb sensitizations is increasing in Germany, which can partly be explained by the cross-reactivity between Hevea brasiliensis (Hb) latex and Fb and the rapidly increasing number of mostly occupational latex allergies. But Fb itself is a potential sensitizer which is widely spread as ornamental plant in homes and offices. As relevant indoor allergen Fb ranks third after housedust mites and pets but before molds among our allergy patients. For diagnosis, prick-tests with Fb-latex seem to be more sensitive than in vitro-methods (RAST, CAPRAST). Fb plants should not be kept in the homes of atopic individuals or persons with latex (Hb) allergy.

Adult↗

Anastomotic leakage: impact on local recurrence and survival in surgery of colorectal cancer.

Anastomotic leakage is a serious complication in colorectal surgery, especially in the treatment of adenocarcinoma located in the left-sided colon and rectum. It is controversial whether anastomotic leakage is a prognostic factor for local recurrence and/or survival in this disease. To evaluate the impact of anastomotic dehiscence on the outcome of surgery we reviewed data on 467 consecutive patients with adenocarcinoma of the left colon and rectum treated between 1985 and 1995 in our Department. Of these, 41 (8.8%) developed anastomotic leakage. The overall-survival differed nonsignificantly (P = 0.57) between leakage and nonleakage groups. Of 331 patients with curative resection 29 showed an anastomotic leakage. There were 46 R0-resected patients who died under disease-related conditions: 7 patients in the leakage group (24.1%) and 39 in the nonleakage group (12.9%; P = 0.045). In the curatively resected group 5 of 29 patients developed local recurrence in the leakage group (17.2%) but only 26 of 302 patients in the nonleakage group (8.6%; P = 0.0357). Multivariate analysis showed only the factors of age, stage of resection, staging of lymph nodes, and tumor staging as independent prognostic factors for overall survival. For local recurrence the multivariate analysis revealed tumor staging and anastomotic leakage as independently significant. Anastomotic leakage thus appears to be a prognostic factor for local tumor recurrence of colorectal cancer. In addition, disease-related survival is considerably decreased under leakage conditions. Anastomotic leakage was not shown in this study to be an independent prognostic factor for overall survival due to the lack of statistical significance.

Adenocarcinoma↗

Low-dose UVA phototherapy for treatment of localized scleroderma.

BACKGROUND: For treatment of localized scleroderma numerous treatments, including ones with potentially hazardous side effects, are currently used with only limited success. OBJECTIVE: We attempted to determine the efficacy of low-dose UVA1 irradiation in patients with severe localized scleroderma. METHODS: Patients were irradiated with 20 J/cm2 UVA1 for 12 weeks (total number of treatments: 30; cumulative UVA1 dose: 600 J/cm2). RESULTS: Low-dose UVA1 irradiation induced significant clinical improvement (clearance of > 80% of lesions) in 18 of 20 patients. Clearance was documented by clinical score as well as by 20 MHz ultrasound and histopathologic analysis. CONCLUSION: Low-dose UVA1 phototherapy can be highly effective for sclerotic plaques, even in patients with advanced localized scleroderma and with lesions rapidly evolving despite conventional therapy.

Adolescent↗

[Microcystic adenoma of the pancreas--a case report].

A 65-year-old female patient with microcystic adenoma of the pancreatic head is reported. Under suspicion of a malignant pancreatic tumour a kephalic duodenopancreatectomy (Kausch-Whipple) was performed. Diagnosis, therapy, prognosis and pathological anatomical aspects of benign microcystic adenoma are discussed.

Adenoma↗

[Gallbladder carcinoma--an unexpected finding after laparoscopic cholecystectomy].

The carcinoma of the gallbladder can be found mostly in a late stage. We have to expect a incidental carcinoma of the gallbladder in 1-2% after conventional cholecystectomy. We report 9 cases of unexpected carcinoma of the gallbladder after 1700 laparoscopic cholecystectomies. The time of survival were--dependent on tumor stage--2 to 36 month. We outline special items of this disease within the context of minimal-invasiv surgery.

Adenocarcinoma↗

[The employment schedule act--effects on the young surgeon].

Since 1. 1. 96, new regulations of working hours have been introduced in our hospital with regard to emergency service and compensation through leisure time. The average payment was reduced by 23% for surgeons on call. By this means, three additional surgeons could be employed. For every resident in training there is now less time for his residency than before. Sufficient surgical residency requires enough time on the ward and in the operating room. Thus, other conditions for residency programs are necessary to avoid unfulfilled tasks being pushed into the pre-existing area of non-documented working hours. Research and any scientific activity take place in leisure time.

Curriculum↗

[Balneophotochemotherapy with 8-methoxypsoralen in lichen sclerosis et atrophicus].

A 66-year-old woman with longstanding lichen sclerosus et atrophicus improved strikingly with PUVA bath photochemotherapy over a period of 6 weeks. The cumulative UVA dose was 31.7 J/cm2; the single UVA dose ranged from 0.3 to 2.3 J/cm2. After 16 treatment sessions, the sclerotic lesions had softened greatly, while after 24 treatments, the skin lesions were almost completely cleared and pruritus was diminished. Histopathological analysis of biopsy specimens from previously affected sites as well as 20 MHz ultrasound examinations showed almost no residual sclerosis. Although long-term results are not yet available, PUVA bath photochemotherapy seems to be a promising and effective new treatment modality without systemic side effects for patients with disseminated lichen sclerosus et atrophicus.

Aged↗

Bovine hemoglobin increases skeletal muscle oxygenation during 95% artificial arterial stenosis.

BACKGROUND: This study investigates the effect of a stroma-free ultrapurified bovine hemoglobin solution (HBOC) on skeletal muscle tissue oxygenation in comparison with hetastarch during nearly complete arterial stenosis. METHODS: Fourteen foxhounds were intravenously anesthetized and mechanically ventilated with 30% oxygen in air. Catheters were inserted into the right femoral artery and vein for measurements of hemodynamic parameters and blood gas sampling. Arterial blood flow of the left popliteal artery was measured by means of an electromagnetic flow probe. Skeletal muscle tissue oxygen tension (tpO2) was measured in the left gastrocnemius muscle by using a stepwise driven polarographic needle probe creating histograms from 200 single tpO2 measurements. After isovolemic hemodilution with Ringer's lactate solution to a hematocrit of 25%, a 95% artificial stenosis of the popliteal artery was established. The animals then randomly received two applications of either 50 ml HBOC (molecular weight, 32,000 to 500,000; hemoglobin, 13 +/- 1 gm/dl-1) or 200 ml 6% hetastarch 200,000/0.5. Variables were measured at baseline, after hemodilution, 30 minutes after stenosis, and 15 minutes after two applications of the respective compound. RESULTS: Demographic data, muscle temperature, and arterial blood gases did not differ between groups. With the exception of higher mean arterial and mean pulmonary artery pressures in HBOC-treated animals, hemodynamics did not differ between groups. In both groups oxygen delivery and oxygen consumption of the muscle decreased in parallel to the decreasing blood flow during arterial stenosis. In contrast, oxygen extraction ratio increased after infusion of HBOC and was higher after the second application when compared with hetastarch-treated animals (p < 0.05). During stenosis tpO2 was decreased in both groups when compared with baseline (p < 0.001). Mean tpO2 remained at decreased levels after administration of hetastarch but increased to nearly baseline values after HBOC treatment (p < 0.001). CONCLUSIONS: The data suggest that increased oxygen extraction in the HBOC group is associated with improved skeletal muscle tissue oxygenation during severe arterial stenosis.

Animals↗

[High resolution 20 MHz ultrasound diagnosis in dermatology for noninvasive imaging of malignant melanomas].

For years, high-resolution b-scan ultrasound is a well established technique in dermatology regarding the preoperative determination of thickness of skin tumors like malignant melanoma or basal cell carcinoma. Most tumors appear as echopoor areas in high-frequency sonography. Until today, a differentiation between skin tumors by means of high-frequency ultrasound is not possible. This is also true concerning the differentiation between the tumor tissue itself and its subtumoral inflammatory infiltration. Therefore, this lack of differentiation leads to the fact that sonometric thicknesses of tumors often exceed the originally measured tumor thickness in histology. By means of three-dimensional reconstruction of serial b-scan images, it is possible to determine each tumor's volume and surface as well as the topographical arrangement of echopoor areas and sonographical structures. Besides high-frequency ultrasound, additional non-invasive techniques like MRI, ultrasound- or laser-doppler, computer-aided image analysis and epiluminescence microscopy are also available for diagnosing malignant melanoma. Epiluminescence microscopy is used today as a standard technique in the diagnosis of malignant melanoma due to the possibility of differential diagnosis. Latest techniques like OCT (optical coherence tomography) are not ready yet to be applied regularly in diagnosis of tumors in the field of dermatology.

Diagnosis, Differential↗

Bovine haemoglobin is more potent than autologous red blood cells in restoring muscular tissue oxygenation after profound isovolaemic haemodilution in dogs.

PURPOSE: This study compares the effects of stored red cells, freshly donated blood and ultrapurified polymerized bovine haemoglobin (HBOC) on haemodynamic variables, oxygen transport capacity and muscular tissue oxygenation after acute and almost complete isovolaemic haemodilution in a canine model. METHODS: Following randomization to one of three groups, 24 anaesthetized Foxhounds underwent isovolaemic haemodilution with 6% hetastarch to haematocrit levels of 20%, 15% and 10% before they received isovolaemic stepwise augmentation of 1 g.dl-1 haemoglobin. In Group 1, animals were given autologous stored red cells which they had donated three weeks before. In Group 2, animals received freshly donated blood harvested during haemodilution. In Group 3, animals were infused with HBOC. Skeletal muscle tissue oxygen tension was measured with a polarographic 12 mu needle probe. RESULTS: In all groups, heart rate and cardiac index were increased with decreasing vascular resistance during haemodilution (P < 0.05). Haemodynamic variables showed a reversed trend during transfusion when compared to haemodilution but remained below baseline (P < 0.05). Arterial and venous oxygen content were changed in parallel to changes of haematocrit and haemoglobin concentrations but were lower in Group 3 than in Groups 1 and 2 (P < 0.05) during transfusion. In contrast, the oxygen extraction ratio was higher in Group 3 (59 +/- 8%, P < 0.01) at the end of transfusion than in Group 1 (37 +/- 13%) and 2 (32 +/- 5%). In Group 3, mean tissue oxygen tension increased from 16 +/- 5 mmHg after haemodilution to 56 +/- 11 mmHg after transfusion (P < 0.01) and was higher than in Group 1 (41 +/- 9, P < 0.01) and Group 2 (29 +/- 11, P < 0.01). While in Group 3 an augmentation of 0.7 g.dl-1 haemoglobin resulted in restoring baseline tissue oxygenation, higher doses of 2.7 g.dl-1 and 2.1 g.dl-1 were needed in Groups 1 and 2 to reach this level (P < 0.01). CONCLUSION: The results show a higher oxygenation potential of HBOC than with autologous stored red cells because of a more pronounced oxygen extraction.

Animals↗

Continuous vectorcardiographic changes in relation to scintigraphic signs of reperfusion in patients with acute myocardial infarction receiving thrombolytic therapy.

OBJECTIVES: Changes in the electrical activity of the heart reflecting the infarct process can be recorded by continuous vector-ECG, a method which is now clinically available for cardiac supervision. Shifts of the ST-segment and QRS-vector reflect ischaemia and necrosis of the myocardium. Continuous vector-ECG changes were evaluated against myocardial scintigraphy in 18 patients with acute myocardial infarction treated with streptokinase in order to study the impact of improved myocardial perfusion. DESIGN: Myocardial perfusion was analysed with 99Tcm-Sestamibi (Cardiolite, DuPont Scandinavia AB, Kista, Sweden) single photon emission computerized tomography (SPECT). Registrations were performed before and after thrombolysis in order to estimate the amount of myocardium with impaired perfusion initially (threatened myocardium) and the degree of perfusion improvement in this myocardial area. X, Y, Z vectors were registered continuously by Frank leads (Ortivus Medical, Täby, Sweden). QRS-vector difference, and the time to plateau phase and the ST-vector magnitude were used as a measurement of ischaemia and size of the myocardial infarction. RESULTS: In seven out of 11 patients treated within 3 h of onset of symptoms, an improvement in myocardial perfusion in the initially hypoperfused areas was achieved in contrast to none of the seven patients treated > 3 h after onset of pain (P < 0.05). In the whole patient material, there was a negative correlation between the time to plateau level for the QRS-vector and the improvement in myocardial perfusion (r = -0.53, P < 0.05). Among patients treated within 3 h, there was a negative correlation between the plateau level for the QRS-vector magnitude compared to the improvement in myocardial perfusion (r = -0.61, P < 0.05) and a negative correlation between the plateau level and the myocardial perfusion level after therapy (r = -0.69, P < 0.05). In these patients, there were also negative correlations between the maximal ST-vector magnitude and the myocardial perfusion both before and after thrombolysis (r = -0.81, P < 0.05 and r = -61, P < 0.05, respectively). CONCLUSION: Patients with marked improvement in myocardial perfusion indicating successful thrombolysis reach their plateau levels of the QRS-change faster and have lower total QRS-vector differences than patients without successful thrombolysis as reflected by myocardial scintigraphy. Patients with a high ST-vector magnitude have low perfusion levels both before and after therapy indicating a pronounced ischaemic damage of the myocardium. Thus, VCG-changes reflect impairment in myocardial perfusion during acute myocardial infarction.

Aged↗