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Biomedical subjects

H Vogel

Publications and source records attributed to H Vogel.

At least 289 records · Page 16Linked to original sources
PubMed1985

Diagnosis and grading of malignancy in squamous epithelial lesions of the larynx with DNA cytophotometry.

For diagnostic purposes 14 histologically benign, 15 dysplastic, and 16 malignant squamous epithelial lesions were subjected to DNA cytophotometry. Results were computed according to an algorithm for DNA diagnosis and grading of malignancy. In cases of unequivocally malignant or benign lesions all DNA diagnoses agreed with the histologic diagnoses. In one case the allegedly faulty DNA diagnosis of cancer was proven to be correct on clinical follow-up. Within the group of histologically mild to moderate dysplasias the algorithm identified four cases as malignant that were proved to be malignant either in the follow-up or at another site of the same lesion. With the aid of the DNA malignancy grade two groups of patients with squamous epithelial carcinomas of the larynx could be discerned with a highly significant difference according to their survival times.

Adult↗
PubMed1985

Fast and slow orientational fluctuations in membranes.

Fluorescence anisotropy measurements on isotropically distributed membranes yield the well-known orientational order parameter as a measure of orientational fluctuations of the fluorophore that are fast compared to the fluorescence lifetime. Measurements on oriented membranes provide four order parameters, two for fast orientational fluctuations and two for slow, from which their approximate angular distributions can be derived. This is exemplified for the fluctuations of lipids in membranes with and without protein. Steady-state fluorescence anisotropy experiments on oriented membranes are carried out, using diphenylhexatriene as a fluorescence probe for lipid fluctuations and melittin as a membrane protein. Protein molecules in a fluid lipid membrane restrict the fast lipid fluctuations and induce slow lipid fluctuations. The angular distribution of the slow fluctuations indicates that lipid molecules at the protein surface are tilted with respect to the membrane normal. The spatial coherence length of these fluctuations is of the order of 15 A.

Journal Article↗
PubMed1985

Hemodynamics and oxygen transport after partial and total blood exchange with pyridoxalated polyhemoglobin in dogs.

The effects of a pyridoxalated polyhemoglobin solution (SFH-PLP)n-solution) on cardiovascular hemodynamics and oxygen transport were investigated in a model of partial and total blood exchange in seven dogs. Cardiac output, mean arterial pressure and heart rate were essentially unchanged, even after total blood exchange, due to the long plasma half-disappearance time of (SFH-PLP)n (36 h) and due to the addition of albumin to the solution. The oxygen-binding capacity of (SFH-PLP)n was 1.1 to 1.2 ml O2/g hb. Oxygen availability was reduced to about 50%, resulting from the low hemoglobin concentration and the decreased oxygen-binding capacity of (SFH-PLP)n. Since cardiac output did not increase, O2-consumption was maintained by an increase in O2-extraction from 21 to about 50%. However the decrease in mixed venous PO2 to values not below 30 mmHg (4.00 kPa) proves the sufficient unloading capacity of (SFH-PLP)n. The adequate tissue oxygenation of (SFH-PLP)n could be demonstrated by the lack of a metabolic acidosis, the essentially unchanged PO2-histograms of the skeletal muscle and the only moderate decrease in mixed venous PO2. Four dogs survived for more than 3 days; three of them were long-term survivors. This suggests that oxygen supply was maintained by (SFH-PLP)n until red blood cells were restored.

Animals↗
PubMed1985

[Indications, procedures and choice of embolization material in transcatheter vascular occlusion].

If it is planned to effect transcatheteral occlusion of vessels, it must be examined whether the relevant vessel should be occluded permanently or temporarily and whether the occlusion should be located centrally in the vascular trunk or in a major twig, or peripherally in the region of the capillaries, arterioles and small vessels. Temporary occlusion with fibrospum is usually sufficient for treating a haemorrhage. Ethibloc or Bucrylate can be employed to shut off an organ and to achieve partial organ necrosis. Arteriovenous connections with a large vascular lumen can be occluded by means of metal particles. Peripherally occluding substances should not be used for embolisations in the gastrointestinal range because of the risk of local necrosis and possible dangerous infection resulting therefrom. To the present day hardly any indications have been found for the use of absolute alcohol. Bucrylate has the drawback, compared against Ethibloc, that the catheter may adhere to the vascular wall. Vessels with a low flow rate should be occluded either by means of balloon catheter or a coaxial catheter system because of the risk of reflux.

Amyloidosis↗
PubMed1985

[Computed tomography following facial surgery].

During the first four to six weeks after surgery, a reaction in the paranasal sinuses can be demonstrated by CT. Similar opacifications appearing later were due to tumor recurrency. Tumor recurrency leads to an increase of soft tissue structures, disappearance of vascular structures, and an increase of bone destruction. The bone destruction can show characteristic fragmentation, with the fragments at a certain distance from each other. If the recurrence is known, CT shows the extension, similar to normal preoperative CT. Follow-up examinations improve safety of interpretation.

Facial Bones↗
PubMed1985

[X-ray findings in deliberately incorporated foreign bodies].

Observations of 181 foreign body introductions in 99 patients are reported. It is possible to differentiate between an oral, transanal, transcutaneous, transurethral, transvenous, transaural way and exceptional cases. Orally introduced foreign bodies up to a length of 12-15 cm usually pass spontaneously: longer foreign bodies must be removed endoscopically or surgically. A special problem is connected with foreign bodies which are swallowed together in a parallel position and form a cross in the stomach. Intravenously introduced foreign bodies like metallic mercury and copper wire were well tolerated by the patients. - Individual observations concern a patient who swallowed a screw driver (about 10 cm in length) and water intoxication in 3 patients (one of whom died) who drank 9-17 liters during 1-2 hours.

Adult↗
PubMed1985

[Scar tissue, organ atrophy and hypertrophy in the computed tomogram after abdominal surgery].

After resection of parenchymal abdominal organs the developing scar tissue is characterised by fat (-30 to -50 H.U.) in connection with mesenchymal funicles. Differential diagnosis presents no problem. Atrophy and hypertrophy may sometimes be demonstrated in CT. This is valid for compensating hypertrophy of the remaining parts of the liver, splenic regeneration or an accessory spleen. Furthermore, involution of the tail of the pancreas after proximal duodenopancreatectomy could be shown in CT. One pancreatic calcification decreased after drainage of a pseudocyst.

Abdomen↗
PubMed1985

[Computer tomography following hypophysectomy].

The authors analyzed the computerized tomograms of 17 patients who had been operated on for tumors in the sellar region. After pituitectomy from a transnasal approach the following was observed: bone defects in the area of the posterior ethmoid cells and at the sphenoid sinus (1), partial absence of the sellar floor (4), a shadow on the ethmoid and sphenoid sinuses (2), an empty sella (1), damaged tissue in the sellar region (1) and blood in the area operated on (1). After pituitectomy from a transcranial approach, the following was seen: trepanation damage frontoparietally on the right (6), trepanation damage frontoparietally on the left (3), brain substance damage below the trepanation (4), and an empty sella (5). The following had occurred as a result of the primary disorder: expansion of the sella (twice), a displacement of the middle structures (twice), bone arrosion in the sella area (once) and a tumor picture in the pituitary area (in eight cases). Air may be encountered postoperatively in the various regions within the calvaria. For the first two weeks at least, its existence is not indicative of the presence of a liquor fistula.

Adenoma↗
PubMed1984

The European vestibular experiments in Spacelab-1.

A series of experiments were performed in the Spacelab-1 mission on November/December, 1983, pre-, in-, and postflight. These experiments covered various aspects of the functions of the vestibular system, the inflight tests comprising threshold measurements for linear movements in three orthogonal axes, optokinetic stimulation, vestibulo-ocular reflexes under linear and angular accelerations, caloric stimulation with and without linear accelerations; pre- and postflight tests repeated the inflight protocol with the addition of subjective vertical and eye counter-rotation measurements using a tilt table. One of the most surprising and significant results was the caloric test: strong caloric nystagmus on the two subjects tested was recorded inflight; this was contrary to what was expected from Barany's convection hypothesis for caloric nystagmus.

Adaptation, Physiological↗