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The authors analyze various orthodontic constructions used in multiple-modality treatment of periodontal diseases. Special attention is paid to combinations of direct fitting with prostheses and use of the novel osteoinductive and immunomodulating agents. Nineteen patients with periodontal diseases were treated. Removable splints, prosthetic splints, and other devices were employed. Special emphasis is made on the use of biositall M-31-a composition on the basis of hydroxyapatite and Algigel. All these materials were found to be effective at the stage of surgical treatment of periodontal diseases, particularly so in combination with immediate prostheses and sodium alginate-based therapeutic films.

A computer-assisted technique was developed for CT-guided stereotactic microsurgical resection of small intracerebral lesions. An original stereotactic retractor was developed to work with the Riechert-Mundinger's equipment for precise localisation, safe exposure and microsurgical removal of these tumours. A software-program was developed to work on an ordinary IBM-compatible PC/AT. It assisted the procedure from treatment planning till the end, including tumour excision, and provided computerized support for the removal of pathological tissues within the CT-defined boundaries of the lesion. 6 patients, harbouring supratentorial intracerebral lesions underwent surgery using this technique. 2 of them suffered from brain metastases, in 1 patient a cavernous angioma was removed, 2 patients had glial tumours, and in the last patient only radiation necrotic tissue was found to be the cause of ring-enhanced lesion, which had been suspected to be a recurrent glioma. Their largest dimensions varied between 18 and 30 mm and the age of the patients ranged from 15 to 52 years. In 2 cases the lesions were localised deeply in the region of basal ganglia and thalamus. In the remaining patients the tumours were rather superficial, infiltrating subcortical white-matter close to the central sulci. There was no mortality nor significant morbidity following the procedure, the Karnofsky Performance Status (KPS) cumulative scores being either unchanged (in 3), or improved (in 3 patients). Current state and modern concepts in image-guided open stereotactic methodology is discussed.

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. Dosimetric planning was conducted by means of an original computer system. Devices and radiation-technical equipment for adaptation of the ANET-B apparatus for irradiation of neurosurgical patients are described. The indications for the use of this method and its place among the complex of measures for the treatment of patients with new growths of the brain are discussed. The first experience in using CT-stereotaxic neutron brachytherapy with californium sources on the ANET-B apparatus for the treatment of 6 patients with malignant glial tumors of the brain is dwelt on.

The article analyses the clinical material concerning 68 patients with various deeply-seated space-occupying processes of the brain (cystic tumors, multiple abscesses, intracerebral hematomas) which were subjected to stereotaxic aspiration on the basis of the findings of computed tomography (CT-stereotaxic punctures). A significant and immediate effect with rapid regression of local and general cerebral symptoms was recorded in 38 patients with cystic intracerebral tumors and craniopharyngiomas. All the patients tolerated the operation well and in none of them were complications encountered. The precision, reliability and safety of CT-stereotaxic punctures--is the basis for such operations as intra-tissue beta-therapy of craniopharyngiomas with radiocolloids, evacuation of intracerebral hematomas, and drainage of multiple brain abscesses. Being an obvious palliative surgical measure, CT-stereotaxic aspiration of deeply-seated cystic tumors is a method of choice in cases in which a direct operation is contraindicated and in patients who are in a grave condition.

CT-stereotaxic biopsy is a modern method for the diagnosis of intracranial tumors. The histological diagnosis established by means of it makes it possible to choose the most rational tactics of treatment and determine more exactly the indications and contraindications for the operation. The examination was conducted on 219 patients with various brain tumors. Authentic histological information was obtained in 84% of cases, 4 patients died, a stable neurological defect developed in another 2 patients. Some methodical procedures for increasing the informativeness and reducing the risk of complications are discussed. An important component is rapid examination of part of the bioptic material by means of smears for intraoperative appraisal of its representativeness and correction of biopsy targets. Among 73 cases in which smears were examined only in 9 the findings were in disagreement with the data of the traditional histologic study, only in the degree of tumor differentiation in all of them. Stereotaxic biopsy is most expedient in situations in which the tactics and main method of treatment are determined to a greater degree by the histological structure rather than by the localization and the patient's general condition. Such cases account for one fourth of all cases of intracerebral tumors.

The authors analyse the results of clinico-CT studies in complicated course of the early postoperative period in 104 patients (87 adults and 17 children) with tumors of the posterior cranial fossa (PCF). According to the histological structure and predominant topography of the neoplasm, the cases were divided into 46 extracerebral parastem tumors (meningiomas, neurinomas, chordomas, cholesteatomas) among which 24 extended supratentorially and 22 to Blumenbach's clivus; 23 gliomas of the cerebellum and fourth ventricle; 16 primary gliomas of the stem; 19 other new growths (hemangioblastomas, hamartomas, choroid papillomas, germinomas). A common factor was coexistence of the main complicating condition--circulatory disorder in the stem with edema and dislocation of the stem, disturbed spatial relations between the PCF structures. Dynamic CT studies allowed the authors to differentiate 3 main variants of pathological changes differing in the character of cerebral circulatory disorders: 1st--a wide zone of reduced density in the brain stem; the extent of this zone in the orocaudal direction and its relation to the diameter of the stem (dorsal, ventral, lateral parts) varied; 2nd--combination of zones of reduced density in the stem and cerebellum with hemorrhagic inclusions--multiple "punctate" inclusions or in the form of blood clots; 3rd--in mosaic pattern of the ischemic foci in the stem and cerebellum there was a prevalence of hemorrhages in the form of multiple small extravasations of blood at different levels of the stem, in the subcortical parts, blood clots in the seat of the tumor, hemotamponade of the brain ventricles.(ABSTRACT TRUNCATED AT 250 WORDS)

255 patients have been examined in the early postoperative period after the removal of tumors located in diencephalic and sella turcica regions. The early postoperative period was complicated by circulation disturbances in the vascular bed of the anterior cerebral or anterior communicative arteries. The clinical pattern, CT scans and morphological data were analysed. Three principal clinical syndromes of the postoperative period were lined out: 1) extrapyramidal-diencephalic syndrome; 2) extrapyramidal-capsular syndrome; 3) frontal-corpocallosal syndrome. The reason for these syndromes was the occlusion of the anterior cerebral and anterior communicative arteries or their branches. The diencephalic syndrome had poor prognosis. The postoperative therapy included hormones. It was necessary to prevent the onset of adrenal insufficiency and diabetes insipidus. The differential diagnosis of thrombosis and vasospasm was of great importance. In case of vasospasm, such medicines as sermion, redergine and nimodipine had a strong therapeutic effect. In vascular thrombosis these medicines were ineffective. Systemic approach to circulation disturbances seems of utmost importance for the analysis of postoperative complications.

As many as 120 neurosurgical patients were examined after the excision of hemispheric gliomas, basal and subtentorial tumors. Based on an the computer-aided analysis biochemical and clinical data, attempts have been made to unify the mechanisms responsible for brain edema development in patients with neurosurgical pathology. In the early postoperative period, brain edema occurs in 95% of neurosurgical patients. Edema development, spreading and intensity depend on the site and nature of the primary pathological focus as well as on traumatism of surgical interventions. It is proved that edema is an original, biologically expedient brain response to its injury. This response manifests in hyperhydration of all tissues, with the maximum intensity being concentrated in the focus of injury. Specific (neurogenic neurohumoral) and nonspecific (biochemical, autoimmune, mechanical, and so forth) factors of brain edema development may be distinguished. The differences in the neurogenic and neurohumoral mechanisms by which brain edema develops may be accounted for by the topography of the focus of injury. The closer the pathological focus is to the stem and diencephalic structures, the more remarkable the action of neurogenous and neurohumoral factors and the more distinct the tendency toward edema generalization are. At the diencephalic level of injury, damaged are the structures responsible for central regulation of metabolism and trophicity of nerve cells. The neurogenously precipitated diffuse impairment of permeability of the cells entails their hyperhydration, which marks cellular (cytotoxic) edema. The subtentorial process that affects the vasomotor centre of the stem triggers the neurogenic diffuse alterations in the vascular tone, manifesting in an increase of permeability for water and plasma proteins which is characteristic of vasogenic edema.(ABSTRACT TRUNCATED AT 250 WORDS)

From clinical analysis of the course of the early postoperative period in 255 patients who underwent removal of extracerebral tumors of mediobasal localization and from clinico-morphological comparison in 24 patients who died, the authors set apart and describe 3 main syndromes of cerebral circulatory disorders in the basin of the anterior cerebral artery: subcortical-diencephalic, subcortical-capsular, and parasagittal. The prognostic significance of each syndrome is shown. The variants of the syndrome are caused by predominant affection (obturation thrombosis, persisting spasm) of different segments of the anterior cerebral artery.

Intercellular adhesion strength was measured after Koman in various parts of primary tumor and lymph node metastases of 43 patients with stage III-IV gastric cancer. Also, a fraction of low-adhesion (less than 0.20 mg) cells was assayed. Intercellular adhesion strength was 0.518 +/- 0.039 mg in primary tumor, 0.260 +/- 0.045 mg--invasion zone and 0.145 +/- 0.028 mg--in metastases. The share of low-adhesion cells was found to be 8.85 +/- 0.26, 65 +/- 4.32 and 87.16 +/- 2.5%, respectively.

Methods for using computer tomography (CT) in stereotaxic calculations are discussed. A stereotaxic CT method elaborated at the Scientific Research Institute of Neurosurgery, AMS USSR which is intended for the Riechert-Mundinger stereotaxic apparatus is described; the method is used for calculating targets chosen according to CT. In combination with a high resolution (ND-8 000) CT-scanner, the method provides for the attainment of targets with a mean magnitude of error of no more than 1 mm in all directions. The calculations are made by means of computer tomograph service programs. The method is simple, reliable in application, and the patient is exposed to relatively small radiation. The method was used in operations for stereotaxic biopsy on patients with deeply located tumors of the brain and is recommended for application in the neurosurgical clinic, mainly in the diagnosis and treatment of patients with tumors of the brain.

Tumor and normal gastric tissue was trypsinized and cell yield in incubation medium was measured 60 and 120 min afterwards. The rate of cell segregation (RCS) [total number of cells after 120 min/total number of cells after 60 min] x 100% was determined. RCS in tumor was higher than in normal tissue. RCS in exophytic carcinomas (208+/-8.1) was significantly lower, relatively higher in endophytic ones (252+/-4.8) and higher in mixed tumors (245+/-8.6). A relationship between type of tumor growth and cell cohesion is suggested.

The report deals with an analysis of a 3-year follow-up of 38 patients of stage III stomach cancer. Tumor tissue disaggregation was investigated in the said patients using methods developed by the authors. The tumor disaggregation rate in patients dead within the first two years after surgery was higher (275 +/- 6.6) than in those dead within three years (237 +/- 10.8) or longer (235 +/- 7.2). High rate of tumor tissue disaggregation proved to be an unfavorable prognostic factor.

The rates of disaggregation of tumor and normal cells of the breast were studied. Intercellular bonds in tumor tissue were found to be weaker than in normal tissue. The expansion of cancer was in close correlation with the weakening of intercellular bonds in tumor tissue. Adhesion of tumor cells is an important factor of metastatic spread.

Local features of the histological structure of malignant glioma tissue are compared with the results of densitometry in computer tomography (CT) with a contrast amplifier. The material for histological examination was collected during stereotaxis biopsy conducted according to CT findings (9 patients) and in examination of the brain of 5 patients who had died without being subjected to operation. The method by means of which anatomical axial sections identical to a series of CT sections were obtained is described. The results in the form of mean values of the coefficients of absorption and the homogeneity of their distribution are shown in accordance with the density of areas with intact brain in each CT section. These data make it possible to detect details of the CT image which are not accessible to visual analysis in some cases and to appraise more objectively the boundaries and spread of the tumors. Besides, they may be used in choosing the targets for stereotaxis biopsy of brain tumors when it is conducted according to the findings of CT. They also increase the informativeness of biopsy.

CT examination of postoperative edema of the brain in 251 neurosurgical patients showed edema to be determined by the location and histostructure of the tumor. The data obtained suggested that the pathogenesis of edema differs. Thus, vasogenous edema develops predominantly after removal of hemispheric gliomas, cytotoxic (hypoxic) edema--after removal of basal-diencephalic tumors, and hydrostatic edema--after removal of subtentorial tumors. It is shown that operative trauma causes hyperhydration of all brain structures.