Optimal requantization of deep grayscale images and Lloyd-Max quantization.

The classic signal quantization problem was introduced by Lloyd. We formulate another, similar problem: The optimal mapping of digital fine grayscale images (such as 9-13 bits-per-pixel medical images) to a coarser scale (e.g.

Functional neurosurgery using 3-D computer stereotactic atlas.

To facilitate a full-scale representation of thalamic nuclei and surrounding subcortical structures in the course of stereotactic procedures, a 3-D computer atlas of this region has been created, which permits visualization of the operative field including the involved structures and the position of the instrument. Necessary adaptation is performed according to the position of the intracranial reference points derived from CT-scan. Working with the atlas permitted more accurate and safer surgery.

[The CT-stereotaxic neutron brachytherapy of brain tumors with californium sources on the ANET-B apparatus].

A method for stereotaxic intratissue radiotherapy of brain tumors based on the findings of computed tomography is described. Radiosurgical implantation of sources with increased 252Cf content emitting mixed neutron + gamma-radiation was accomplished by means of an ANET-B apparatus by the afterloading method. Neutron irradiation is particularly effective in patients with malignant tumors possessing a large fraction of cells in a state of deep anoxia.

[Intraoperative monitoring of the EEG in patients with arterial aneurysms of the cerebral vessels].

Visual EEG monitoring and EEG monitoring using a special "Neuro-2" monitor controlling the changes in quantitative EEG parameters (power range and coherence) have been used during surgery in 42 patients with arterial aneurysms of brain vessels performed in conditions of profound controlled arterial hypotension. Computer processing facilitates EEG analysis and reveals the most early signs of the developing cerebral ischemia on the basis of specific changes in power ranges and coherence.

A polymer carrier system for taste masking of macrolide antibiotics.

A polymer carrier system was developed to reduce the bitterness of erythromycin and its 6-O-methyl derivative, clarithromycin, by absorption to Carbopol. The mechanism involves ionic bonding of the amine macrolide to the high molecular weight polyacrylic acid, thereby removing the drug from the solution phase in an ion-free suspension. After ingestion, endogenous cations displace the drug from the polymer in the gastrointestinal tract to achieve bioavailability.