Search PubMed⌕ Search

Biomedical subjects

M Lenz

Publications and source records attributed to M Lenz.

124 records · Page 7Linked to original sources

[Side effects, complications and contraindications for percutaneous sclerotherapy of the internal spermatic vein in the treatment of idiopathic varicocele].

The results of 230 retrograde phlebographies of the V. spermatica int., 165 percutaneous sclerotherapies and 60 follow-up phlebographies on subfertile patients are presented. In 24 patients (10%) complications occurred, yet in none of the cases clinical damage became evident. Percutaneous sclerotherapie is contraindicated, when selective probing of the V. spermatica int. is impossible or massive collaterals to other venous systems could lead to an uncontrolled spread of the sclerosing agent. Treatment of idiopathic varicocele in subfertile men by percutaneous sclerotherapy is a safe and effective method, which can be performed on an outpatient basis. In our opinion the so far used surgical treatment can be replaced by it as a method of choice.

Collateral Circulation↗

[Computed tomography of cervical lymph node metastases in malignant tumors of the head and neck region].

The lymphatic spread in 123 patients with biopsy-proven malignant head and neck tumors was evaluated by CT in a prospective study. In 53 cases, clinical examination, CT and pathological-histological work-up of the surgical specimens were comparatively analysed. The fraction of false-negative judged lymph nodes by palpation was 21%. This high error in judgement could be diminished to 7.5% by the use of CT. 83% of squamous cell metastases showed a central decrease in density due to necrosis after intravenous infusion of contrast material.

Carcinoma, Squamous Cell↗

[The value of computed tomography in the diagnosis of malignant oral tumors and their local metastases (author's transl)].

Forty-six computed tomographic examinations on 39 patients with histologically confirmed malignant oral tumors are reported on. The value of information by CT is compared to clinical staging in 24 operated cases. In determination of the T-category, clinical examination is superior to CT. The local metastases and the outline of the tumor are better diagnosed by CT. Provided that a subtle examination technique is used, CT can be of great help to the surgeon in choosing the adequate therapy in oral malignant tumors.

Adult↗

[Value of computer tomography in comparison to mediastinoscopy and test thoracotomy in intrathoracic space-occupying lesions with mediastinal involvement].

The preoperative CT findings in 50 patients out of a total of 144 examined patients with suspected intrathoracal malignant processes with mediastinal involvement were compared to the results obtained by mediastinoscopy and thoracotomy. There was a high diagnostical reliability (95%, n = 40) in assessing lesions in the area, which can be reached by mediastinoscopy. This leads to the conclusion that mediastinoscopy is necessary only in such cases with histologically proven malignant intrathoracal masses, which show lymph nodes of a size from 1 to 2 cm. The evidence of invasive extension into adjacent mediastinal structures as well as the distance from tumour to carina could be assessed well by CT. For follow-up examinations after resection, radiation therapy or chemotherapy, computed tomography is of particular value to detect early mediastinal recurrence.

Adenocarcinoma↗

[Prospective comparison of ARTOSCAN-MRI and arthroscopy in knee injuries].

The results of magnetic resonance imaging (MRI) were compared with those of arthroscopy in a prospective series of 276 patients. A "dedicated system" for MRI of limbs and peripheral joints--the 0,2 Tesla ARTOSCAN (ESAOTE, Italy)--was used for imaging knee joint lesions. T1-weighted spin echo sagittal images, T2-weighted gradient-echo coronal images, and axial views for lesions of bone and the femoropatellar joint were acquired. If necessary paraxial sagittal and oblique coronal views were obtained for imaging of the cruciate ligaments. This protocol allowed excellent visualization of the cruciate ligaments, medial and lateral meniscus in almost all patients. Compared with arthroscopy performed within 48 hours after imaging, the sensitivity, specificity, and accuracy were respectively, 91, 92 and 91 per cent for tears of the medial meniscus; 80, 96, and 92 per cent for tears of the posterior meniscus; 100, 100, and 100 per cent for tears of the posterior cruciate ligament; 93, 98, and 99 per cent for tears of the anterior cruciate ligament; and 73, 100, and 92 per cent for full-thickness articular cartilage lesions. The examination can be performed within 30 to 45 minutes at a cost that is lower than that of diagnostic arthroscopy. ARTOSCAN imaging is a safe and valuable adjunct to the clinical examination of the knee and an aid to efficient preoperative planning.

Adolescent↗

A randomized comparison of rescuer positions for intubation on the ground.

OBJECTIVE: To examine the ease of endotracheal intubation on the ground for various rescuer positions. METHODS: Six female and 18 male emergency medical technicians were asked to intubate a Laerdal Megacode Trainer placed on the ground. Rescuers assumed the following positions in random order: prone, sitting, kneeling at the mannequin's head, and straddling the chest. The authors measured times 1) for changing from mask ventilation to assuming intubation position and 2) from touching the laryngoscope to putting it down. Incidences of esophageal tube placement and clicks (possible tooth damage) were noted. The rescuers rated their satisfaction with each position on a six-point scale (1 = very good, 6 = insufficient). Total intubation times of the other three positions were compared with that for prone by rank order test for paired observations. Handling, esophageal positions, and clicks of the other three positions were compared with those for prone by sign test for paired observations. A Bonferroni correction (factor 12) was applied. RESULTS: Mean total intubation times (in seconds) were 11.8 +/- 3.3 for prone, 13.9 +/- 4.7 for sitting, 11.4 +/- 4.5 for kneeling, and 16.2 +/- 5.8 for straddling. The difference between straddling and prone was statistically significant (p < 0.005). For handling, the results were for prone 3.0 +/- 1.4, for sitting 3.1 +/- 1.1, for kneeling 2.2 +/- 0.6, and for straddling 2.8 +/- 1.4. Esophageal positions occurred for prone 1, for sitting 1, for kneeling 2, and for straddling 3. Clicks were counted for prone 2, for sitting 1, for kneeling 1, and for straddling 0. CONCLUSIONS: All tested positions provide satisfactory conditions for intubation on the ground. The straddling position requires statistically, but not clinically, significantly more time for intubation than does prone and may be an important backup position if access from behind the patient's head is impossible.

Adolescent↗

MRI results from investigation of head and neck tumors.

A comparative study between MRI and CT was done with particular reference to the head and neck regions. Compared with CT, MRI offered better tissue contrast, vascular visualization without the need for iodinated contrast media, direct coronal scanning, and a special surface coil for high spatial resolution. MRI is a promising modality for this region despite its difficulty in visualizing bone and its slightly poorer spatial resolution.

Head and Neck Neoplasms↗

[Comparative hemodynamic evaluations of varicocele by bidirectional ultrasonic Doppler sonography and phlebography of the internal spermatic vein].

Clinical studies (degree of severity) and bidirectional ultrasonic Doppler sonography (Pressure-type, Shunt-type) of varicocele were compared with the phlebography of the internal spermatic vein (degree of spermatic incompetence, diameter of the int. spermatic v.). Doppler probe and phlebography are equivalent methods to demonstrate the venous reflux in palpable varicocele and for follow-up examination after sclerotherapy. The subclinical varicocele is discussed. The slight degree of spermatic incompetence (reflux by Valsalva's manoeuvre) is responsible for the small varicocele (grade I) and the Pressure-type. The severe degree of spermatic incompetence (spontaneous reflux) causes the Shunt-type and the large varicocele (grade III) as well as a dilatation of the internal spermatic vein.

Hemodynamics↗

Cholesterol based antineoplastic strategies.

Manipulation of cholesterol metabolism open several possibilities of interfering with the growth of malignant cells. Deprivation of cholesterol decreases the velocity of growth and alters the composition of the cell membrane. The high requirement for LDL of malignant cells can be utilized for drug targeting. Proliferation assays were performed with neuroblastoma cells and cell lines of acute myeloid leukemia deprived of cholesterol by inhibition of HMG-CoA-reductase or culture in LDL-deficient medium. The cholesterol content of the cell membrane when reduced to 50% had no effect on the toxicity of LAK-cells but the toxicity of the fluorescent dye merocyanine MC 540 was enhanced two-fold. LDL-mediated drug targeting to AML cells was performed with oxidized LDL and showed toxic reactions. These results proved that cholesterol deprivation could be used to support some therapeutic approaches.

Anticholesteremic Agents↗