Method for estimating osteogenesis intensity
SUBSTANCE: method involves applying computer-aided processing of general plan survey X-ray films with one or several zones of interest being detected on digitalized image corresponding to the number of osteogenesis foci. Quantitative osteogenesis intensity estimate is obtained by applying test grid and interpreting ratio of areas corresponding to distraction regenerate mineralization degree. Boundaries are determined in each zone of interest for delimiting intensity ranges characterizing tissue mineralization degrees at osteogenesis stages and reference points are marked. The first reference point is selected on proximal bone fragment end turned to diastasis. Lower boundary line of the proximal test grid, composed of parallel lines being perpendicular to long bone axis, is superposed with the first reference point. The second one is selected on distal bone fragment end turned to diastasis and the upper line of the distal test grid is superposed with it. Every region belonging to a zone of interest confined by neighboring test grid lines is segmented within the scope of established boundaries into intensity ranges and intensity range area shares in the total area of each region belonging to zone of interest. The intensity range area share proportions are used for estimating osteogenesis intensity.
EFFECT: wide range of functional applications.
The invention relates to medicine, namely to traumatology and orthopedics, and can be used to assess the status or current bone formation in patients and experimental research works.
Known "Method of distraction osteosynthesis", involving the assessment of the intensity of bone formation by roentgenometry connective tissue layer formed bone regeneration (RF Patent No. 2102022 published 20.01.98, Bulletin No. 2).
However, this method is applicable for a particular case - distraction osteogenesis and does not allow to assess bone formation in regenerating or growing in the osteogenesis of bone.
The known method stereological assessment of distraction osteogenesis, in which carry out computer processing review of radiographs, there is a digitized image of one or more zones of interest, according to the number of foci of bone formation, and using a test grid, get a quantitative assessment of the intensity of bone formation by the ratio of areas, reflecting the degree of mineralization of the distraction regenerate (RF Patent No. 2165243 published 20.04.2001, bull. No. 11).
However, obtained with the help of this method the results are not reflective of the intensity of the regeneration process to the local tissue.
The task of the invention is to increase the information content and the expansion of the scope of method study bone formation.
This task is solved in that in the method of estimating the intensity of bone formation by computer processing review of radiographs, the selection on the digitized image of the one or more zones of interest, according to the number of foci of bone formation, and using a test grid, obtaining a quantitative assessment of the intensity of bone formation by the ratio of the areas. reflecting the degree of mineralization of the distraction regenerate, for each zone of interest define the boundaries of the ranges of intensities, reflecting the degree of mineralization of the tissue on the stages of bone formation, and identifying a reference point, the first point is chosen on facing the diastasis end of the proximal bone fragment and combined with her extreme line proximal the test grating consisting of parallel lines perpendicular to the long axis of the bone, and the second anchor point is chosen on facing the diastasis end of the distal bone fragment and combined with her extreme upper distal line of the test grating, each area of interest, limited adjacent lines of the test gratings, segments according to the established boundaries the ranges of intensity and Radelet share space ranges of intensities in the total area of each area of interest, the ratios of the areas of the ranges of intensities assess the intensity of bone formation.
The invention is illustrated by the description, an example of practical use and illustrative material, which shows:
figure 1 - initial radiograph of the bone;
Figure 2 radiograph of the bone with contoured area of interest;
figure 3 radiograph of defined reference points;
figure 4 - integerrima with the test grid on the proximal fragment;
5 is a radiograph of the test gratings on both fragments;
6 is a radiograph with the combined test gratings;
Fig.7 - radiograph with the area of interest, separated by lines of the test grating on the land;
Fig - table space distribution of test levels of the distraction regenerate by band intensity (mineralization);
figure 9 is a graphical representation of the ratio of the area of the ranges of intensities, reflecting the degree of mineralization of the distraction regenerate and bone fragments on the 14th day of distraction;
Figure 10 - graph of ratio of area proportions-ranges of intensities. reflecting the degree of mineralization in the selected area of interest on the 14th day of distraction:
11 is a chart of the ratio of area proportions ranges intensive gene. reflecting the degree of mineralization of distrac the ion regenerate on the 14th day of distraction.
The method is as follows.
On the digitized images, review x-rays emit one or more zones of interest according to the number of foci of bone formation.
In each zone of interest outline control points, which serve as a guide for applying the test grating consisting of parallel lines perpendicular to the long axis of the bone. Thus take into account that the fragments of bone at different stages to converge (when compression in the treatment of a fracture) or away from each other (when the distraction osteosynthesis). Therefore, the first anchor point is chosen on facing the diastasis end of the proximal bone fragment and combine extreme bottom line proximal the test grating.
Then choose the second anchor point on facing the diastasis end of the distal bone fragment and combined with her extreme upper distal line of the test grating.
After that, both of the test grating gradually completed equals the number of steps from the reference points in the direction of diastasis towards each other as long as the distance between the extreme lines of the gratings will not be less than twice the step (understanding under step the distance between the lines of the test grating). This method of combining test gratings with the image area of interest allows standardized, is operatiu test levels. For the zero line of the test grating accept those that are aligned with the anchor points at the proximal and distal bone fragments. This gives you the opportunity to select for the analysis of comparable areas in reseating radiographs, even in cases when the height of the diastasis between the bone fragments is changed.
After this, taking into account the intensity of a particular x-ray image sets the boundaries of the ranges of the intensity of the investigated area of interest, while highlighting areas of medium (shadow bone medullary canal) and high (shadow cortical plates) degree of rentgencontrastnoe, as well as the portions that correspond to the intensity of the image of the shadow of soft tissue. The degree of intensity of the image of each of the following sections and their corresponding boundary values are expressed in arbitrary units of intensity, which when using appropriate software (for example, a set of specialized programs for hardware-software complex "Dimorph", Moscow, Russia)are set automatically.
Using these boundary values of the intensity image, each test level (area of interest, limited adjacent lines of the test grating segments on the ranges of intensity. Receiving the hydrated digital material process and bring in the table, on the basis of which determine the proportion of the squares of the ranges of intensities in the area of each of the investigated area and hearth bone formation in the whole.
To simplify the analysis of digital material and clarity of the process of bone formation, on the basis of data tables can be constructed graphs that characterize the area of interest and each of its sections.
Practical implementation of the method is illustrated by the following example.
Dog No. 1191, age at the time of surgery 2 years, were lengthening of the right tibia. Examined the radiographs of the operated limb on the 14 days of distraction.
The x-ray image entered in the computer memory using a camera or scanner. Made of geometrical and optical calibration image. In interactive mode, the highlighted area of interest distraction regenerate and adjacent the ends of fragments of the tibia).
The histogram of the intensities in the image area of interest was defined border ranges, reflecting the degree of mineralization of the tissue on the stages of bone formation. On the same image set of reference points on the ends of the proximal and distal fragments belieberboy bones. On each of the bone fragments imposed on the test grating of parallel lines perpendicular to the long axis of the bone, so that the x extreme facing the diastasis, lines are aligned with the corresponding anchor points.
After that, both of the test grating was gradually added to equal the number of lines in the direction of diastasis towards each other as long as the distance between their extreme lines was not less than double step. Combined with the reference line points of the test grating was defined as zero and correspondingly numbered test levels (the zone of interest, limited adjacent lines of the test grating.
Then each level has planimetrically and segmented by intensity, using previously established boundary values of the ranges. The digital material is made in the table on the basis of which identified the percentage of the areas of ranges in the total area of each test level and areas of interest in General. The results of the calculations are shown in graph 1.
The study of a digitized image of this landmark x-rays allowed us to obtain a quantitative assessment of lesion of bone formation. The analysis of the received digital data has shown that in this case was active osteogenesis, as evidenced by the ratios of the areas of the ranges of intensities, reflecting the degree of mineralization of the distraction regenerate. Share remineralizing component in Piazza di is stasis (the distraction regenerate) was 24%, brackish - 34%, moderately mineralized - 42%, saline - 0%. The total area of the zone of interest, comprising in addition to regenerate and prioralye areas of bone fragments, the share remineralizing component - 9%, brackish -15%, moderately mineralized - 65%, saline - 11%.
Using the proposed method provides a more informative and objectivity of research results hearth bone formation.
The method of estimating the intensity of bone formation by computer processing review of radiographs, the selection on the digitized image of the one or more zones of interest, according to the number of foci of bone formation, and using a test grid, obtaining a quantitative assessment of the intensity of bone formation by the ratio of areas, reflecting the degree of mineralization of the distraction regenerate, characterized in that for each zone of interest define the boundaries of the ranges of intensities, reflecting the degree of mineralization of the tissue on the stages of bone formation and outline control points, with the first anchor point is chosen on facing the diastasis end of the proximal bone fragment and combined with her extreme bottom line proximal the test grating consisting of parallel lines perpendicular to lengths of the second axis of the bone, and the second anchor point is chosen on facing the diastasis end of the distal bone fragment and combined with her extreme upper distal line of the test grating, each area of interest, limited adjacent lines of the test gratings, segments according to the established bounds on the ranges of intensity and determine the proportion of the squares of the ranges of intensities in the total area of each area of interest, the ratio of area proportions ranges of intensities assess the intensity of bone formation.
FIELD: medicine, surgery.
SUBSTANCE: amputation should be fulfilled at the level of cuboid and navicular bones, as an arch-like trimming in plantar-rear direction without affecting tarso-calcaneal-cuboid-navicular articulation for removing wound defect, that forms a callosity partially uniting both bones at keeping the fixation of tendinous plantar aponeurosis at trimming level that strengthens the present area and decreases further possibility for the development of stump's equines deformity and provides prophylaxis in developing trophic disorders.
EFFECT: higher efficiency.
2 dwg, 1 ex
FIELD: medicine, neurosurgery.
SUBSTANCE: the present innovation deals with treating patients with hernias of intervertebral lumbar disks: out of yellow ligament one should cut "an apron" and on a ligature the latter should be applied towards spinous processes, after removing disk hernia the "apron" of yellow ligament should be put into inter-arch space to be fixed with a suture that does not restrict the survey of operational field and keeps normal anatomical interactions in inter-arch space, prevents the development of postoperational muscular-membranous cicatrix and adhesive process in epidural fiber.
EFFECT: higher efficiency.
1 dwg, 2 ex
FIELD: medicine, orthopedics.
SUBSTANCE: in the course of dosed lengthening limbs; segments, at initial stage of fragments' traction a patient should be prescribed the seances of hyperbaric oxygenation and acupuncture. At its middle stage one should perform the course of medicinal therapy. And at its final stage the latter should be supplemented with the course of hyperbaric oxygenation. At stage of fixation it is necessary to carry out successively altering courses of medicinal therapy, acupressure and hyperbaric oxygenation. The innovation prevents the development of contractures in adjacent joints and avoids neurological complications.
EFFECT: higher efficiency.
1 cl, 2 dwg, 1 ex
FIELD: medicine, orthopedic, traumatology.
SUBSTANCE: one should perform, at minimum, a double osteotomy of a bone followed by a dosed longitudinal shift of isolated fragments till restoration of desired osseous length, replace intermediate fragment against longitudinal axis of the segment during the shift and move it in this position longitudinally. In peculiar case, at simultaneous shift of several intermediate fragments their adjacent ends should be replaced in opposite directions. In peculiar case, during osteotomy in adult patients one should perform periosteal exfoliation at the ends of intermediate fragment under development. The innovation enables to form steadily a regenerate which is capable to withstand statico-dynamic loading after reconstruction.
EFFECT: higher efficiency of osseous lengthening.
2 cl, 4 dwg, 1 ex
FIELD: medicine, traumatology, orthopedics.
SUBSTANCE: one should alter the loading upon the caput due to the following technique: one should model adjacent surfaces of caput femoris and collum femoris, moreover, it is necessary to isolate the least affected cartilaginous surface of the caput which would be a support one after osteosynthesis, then one should put the caput upon adapted surface of the collum, introduce the screws of graphitized cast iron retrogradely coaxially against the collum from the side of the caput through fracture area, moreover, the screws should pass through the second cortical layer. The innovation enables to create conditions for steady loading upon the caput femoris.
EFFECT: higher efficiency of therapy.
3 dwg, 1 ex
FIELD: medicine, traumatology, orthopedics.
SUBSTANCE: for surgical correction of caput femoris defect in case of aseptic necrosis, osseous cyst, osteochondropathy of caput femoris. Towards the defect one should form a trepanation foramen in anterior department of collum femoris, remove necrotized sections of caput femoris through developed canal subchondrally and substitute with reduced autotransplant taken out of ilium's wing, then trepanation canal should be filled in with developed osseous column that keeps sphericity of caput femoris in case of loadings and its own articular cartilage.
EFFECT: higher efficiency of autoplasty.
5 dwg, 2 ex
FIELD: medicine, traumatology.
SUBSTANCE: one should substitute affected ligaments with doubled tendon of semitendinous muscle. For this purpose one should conduct tendolysis to remove a tendon, then one should drill intraosseous canals: in the collum of ankle bone - in cross-sectional direction, in the body of a heel bone - in longitudinal direction, and in fibula - in anterior-posterior direction and from the top downwards at the angle of 45° so, that output opening should be in area of the lower pole of external ankle. After that, a tendinous transplant should be applied through a canal in an ankle bone, then - into the canal in fibula and heel bone and after withdrawing out of the heel bone it should be applied in back direction through fibular canal to be sutured with a free end that protrudes from the canal of ankle bone with tendinous suture by "end-to-end" type. The method enables to perform operative treatment in case of chronic lesions of fibular ligaments in talocrural joint.
EFFECT: higher efficiency of autoplasty.
FIELD: medicine, orthopedics.
SUBSTANCE: the method deals with an access to the caput and bottom of the 1st metatarsal bone, removal of osseous-cartilaginous growth in area of metatarso-phalangeal joint, cut a fragment out of articular capsule with its bottom being on proximal phalanx, suturing a cut fragment at tension towards soft tissues in area of distal metaepiphysis of the 1st metatarsal bone to withdraw the great toe out of defective position, resection of the bottom of proximal phalanx in a hammer-like toe, osteotomy of the bottom of the 1st metatarsal bone, forming wedge-like autotransplants out of resected bottom of proximal phalanx of the second toe followed by their introduction into area of osteotomy of the bottom of the 1st metatarsal bone to prevent the relapse of deformation.
EFFECT: higher efficiency of therapy.
2 dwg, 1 ex
FIELD: medicine, orthopedics, traumatology.
SUBSTANCE: one should remove nonviable tissues, apply femoral end into the edges of both opposite shin bones, perform fixation till fusion with the help of compression-distraction apparatus. In peculiar case, at treating affected articular ends one should dissect and keep proximal fibular end. In peculiar case, at bringing together opposite ends of the bones the area of their contact should be overlapped with dissected fibular fragment and patella. The method enables to increase mechanical strength of fusion.
EFFECT: shortened terms of therapy.
2 cl, 4 dwg, 1 ex
SUBSTANCE: one should bring together pubic bones with a polymeric monofilament by successively applying double-curved monofilament through an obturator foramen from one side by developing a loop around pubis, then, similarly one should develop a loop around another pubis to apply conductors out of flexible nonabsorbable material under the loops developed to be then tightened into a knot, due to applying metallic tightening under knots one should introduce a one-tooth hook into foramen between the knots of monofilaments to twist them together, thus, performing a juncture of pubic bones up to desired distance with effort of 35 kg, not more, then monofilaments should be fixed due to twisting the ends with a pre-applied octagonal wire loop being under their knots by closing it as the tightening.
EFFECT: higher efficiency in preventing post-operational complications.
7 dwg, 3 ex, 2 tbl
FIELD: medicine, stomatology.
SUBSTANCE: in patients with defects of dental rows one should conduct masticatory testing, masticatiography and registration of somatoautonomic values (arterial pressure, heart rate) simultaneously before, during and after the end of orthopedic therapy to calculate the index of adaptive effect of masticatory system that characterizes the profitable ness of masticatory system. Due to comparing the values of the index of adaptive effect of the system with average values of efficiency optimum for different types of prostheses one should evaluate the result of orthopedic therapy and adaptational body capacities to plan further rehabilitation measures. The innovation enables to obtain objective evaluation of masticatory functional activity in patients in the process of orthopedic therapy.
EFFECT: higher efficiency of evaluation.
2 ex, 2 tbl
FIELD: medicine, obstetrics.
SUBSTANCE: the present innovation deals with predicting disadaptive processes in women in dynamics of menstrual cycle. During menstrual cycle beginning since the 1st d to the 21st d one should detect the dynamics for alteration in coefficient of activity of syntoxic adaptation programs (CASAP), calculated by the following formula:
where CST - concentration of blood serotonin, AAT-III - activity of antithrombin III, Aaoa - total antioxidizing activity of plasma, CCD8 + - concentration of T-suppressors, Cad - concentration of blood adrenalin, Cα2MG - concentration of α2-macroglobulin, CMDA - concentration of malonic dialdehyde, CCD4 + - concentration of T-helpers. Moreover, normally CASAP value alters two-fold against the first day of the cycle - since 0.70 up to 1.40 on the 21st d of the cycle, at no alterations in CASAP value one should diagnose female disadaptive alterations leading to failed pregnancy. The innovation enables to perform diagnostics of disadaptive processes in women in dynamics of menstrual cycle followed by prognostic conclusion upon future pregnancy.
EFFECT: higher accuracy of diagnostics.
FIELD: medicine, oncourology.
SUBSTANCE: one should choose the number of points for biopsy : 1 point of biopsy/5 cu. cm of an organ, then it is necessary to detect the portion of cancerous parenchyma in bioptates in percentage morphometrically due to analyzing of not less than 1000 points minimum in 5 sections of preparation, the volume of cancerous parenchyma in an organ should be detected by the following formula:
where X - average value for the portion of cancerous parenchyma in an organ, in %; ΣA - the portion of cancerous parenchyma in bioptate in %; N - the number of bioptates. The present innovation enables to detect cancerous parenchyma both in case of interrupted and diffused forms of prostatic cancer.
EFFECT: higher accuracy of detection.
1 dwg, 3 ex
FIELD: medicine, pathological anatomy.
SUBSTANCE: the present innovation deals with detecting viability in neonatals of 22-27-wk-long gestation, at their body weight up to 1 kg based upon evaluation of thymic morphological maturity. Moreover, in 10 visual fields in medullary substance in thymic lobules one should calculate the content of Hassal's bodies and reticuloepithelial cells. If the content of reticuloepithelial cells is above 10 and Hassal's bodies - above 2 one should consider a neonatal to be a viable one, at the content of reticuloepithelial cells being below 9 and Hassal's bodies - below 2 - as nonviable one. This method enables to detect quantitative criteria in evaluating the viability in neonatals at extremely low body weight by thymic state for the first time, helps to increase accuracy and simplify pathologoanatomical diagnostics of viability and objectively evaluate tactics and purposefulness of resuscitation procedures.
EFFECT: higher accuracy and efficiency of evaluation.
3 ex, 1 tbl
SUBSTANCE: the present innovation deals with predicting opisthorhiatic hepatic and gastro-duodenal lesions. In the course of esophagogastroduodenoscopy one should evaluate the degree of mucosal lesion in pyloric gastric department, and, also, the presence and degree of duodenogastric reflux, in case of which one should introduce a flexible catheter into duodenal bulb through biopsy canal of a gastroduodenoscope followed by aspiration of duodenal bulb's content under visual control followed by direct microscopy of this content with the purpose to detect helminthic eggs. During sampling the content of duodenal bulb one should introduce a catheter there being at 1-1.5 cm against pyloric bagasse and up to the major duodenal papilla one should perform slipping movements above mucosal surface. Aspiration should be fulfilled into a 10-20-g-syringe for 2-3 min. The method enables to detect infection with opisthorchiasis at low intensity of opisthorchiatic invasion.
EFFECT: higher accuracy of diagnostics.
FIELD: epidemiology and dermatology.
SUBSTANCE: invention, in particular, relates to such infective diseases as syphilis, gonorrhea, chancroid, urogenital chlamidiosis, etc. By questioning a person, additional information is collected concerning sexual partners during a year and average number of coituses with one partner. Probability of contacting a contagious sexual partner in male/female population (Pm/f) is then found from following formula: Pm/f ~ (mDf/mQf/m)/(Mqf/mAP), where m/M represents infection danger factor (m is annual number of diseased persons and M population number); Df/m duration of infection period for women and men, respectively; Qf/m percentage of women and men, respectively, in population; A percentage of sexually active persons in population; and P percentage of persons with polygamous behavior in sexually active population. After that, contagion probability is determined by calculating annual individual infection risk using following formula: annual individual infection risk , where is average probability of contagion with given sexually communicating infection caused by one coitus; average number of coituses with each partner; probability for each partner to be infected and N number of sexual partners in unit time period.
EFFECT: enabled estimation of individual risk of infecting with different sexually communicated infections in regard to different infections and regarding selected population.
2 cl, 3 tbl, 4 ex
FIELD: medicine, phthisiology.
SUBSTANCE: one should carry out test-therapy with antibiotics, moreover, preparation should be introduced into subcutaneous fiber of pre-tracheal area, subaxillary area at the side of lesion once daily at the dosage of 1/2 - 2/3 against the age daily dosage and 7-10 d later in case of roentgenologically proved healing of pulmonary inflammatory alterations one should state upon pneumonia, and in case of kept inflammatory alterations - tuberculosis. The present method enables to shorten the terms of diagnostics that, in its turn, enables to carry out corresponding therapy in due time and, thus, prophylaxis of possible jatrogenic complications.
EFFECT: higher efficiency of diagnostics.
SUBSTANCE: invention is destined for use in hospitals, addiction dispensers, and Department of forensic medical examination when determining narcotic intoxication. For that aim, morphologic examination of hepatic tissue (obtained through biopsy or autopsy) is performed and condition of cells of monocytic-macrophage system of liver is estimated. When increased level of endoteliocytes in sinusoids in periportal region relative to remaining part of parenchyma is observed, acute narcotic intoxication is determined and, when these changes are observed across all surface of hepatic segment, chronic intoxication of human organism is stated.
EFFECT: enabled distinguishing acute and chronic forms of narcotic intoxication.
SUBSTANCE: method involves applying flexible dental cappa plates having built-in radiopaque net set congruently to gingiva contour when being manufactured, and radiopaque thread placed on dental pocket bottom around teeth under study. Mesh diameter is equal to 1 mm. Several dental pocket depth values are measured. Total failure scale in periodontium is determined from formula CP=(D1+D2+…+Dn)/(L1+L2+…+Ln)*100%, where CP is the periodontium destruction degree, D1,D2,…Dn mean depth of each bone pocket in mm, L1,L2,…Ln is the total length of tooth root in mm. CP value being below 20%, I degree periodontium failure is diagnosed. The value being from 20 to 50%, II degree periodontium failure is diagnosed. The value being higher than 50%, III degree periodontium failure is diagnosed.
EFFECT: high quality of diagnosis.
SUBSTANCE: method involves analyzing symptoms manifesting initial disseminated intravascular blood coagulation syndrome danger like burn area, availability of upper air passages burn, shock with its severity degree taken into consideration, sepsis development; clinical manifestations of disseminated intravascular blood coagulation syndrome like lung, kidney, liver function insufficiency, cerebral dysfunction, local and multiple hemorrhages, thrombosis, infarction; homeostasis system laboratory analysis data, hyper- and hypocoagulation based on chronometry test data, number of blood platelets, fibrin-monomer complexes, D-dimers, activity of antithrombin III, C and S proteins, XIIa-dependent fibrinolysis plasminogen content, availability of injured erythrocytes, combinations of laboratory tests for recognizing disseminated intravascular blood coagulation syndrome. Each sign under consideration receives a number of points corresponding to its diagnostic significance and integral value is calculated DIBCSIV=(X1+X2+…+Xn)/n, where n is the number of signs taken into consideration. DIBCSIV value equal to 1.0-1.5 units shows physiological norm. The value being between 1.6 and 2.5 units, light disseminated intravascular blood coagulation syndrome is diagnosed. The value being between 2.6 and 3.5 units, disseminated intravascular blood coagulation syndrome of medium severity is diagnosed; 3.6-4.5 points to one heavy severity degree; 4.6 and greater indicates highly severe case of disseminated intravascular blood coagulation syndrome.
EFFECT: high accuracy and objectiveness in differentiating syndrome severity degrees.
FIELD: medicine, clinical toxicology.
SUBSTANCE: at patient's hospitalization one should gather the data of clinical and laboratory values: on the type of chemical substance, patient's age, data of clinical survey and laboratory values: body temperature, the presence or absence of dysphonia, oliguria being below 30 ml/h, hemoglobinuria, erythrocytic hemolysis, exotoxic shock, glucose level in blood, fibrinogen and creatinine concentration in blood serum, general bilirubin, prothrombin index (PTI), Ph-plasma, the state of blood clotting system. The state of every sign should be evaluated in points to be then summed up and at exceeding the sum of points being above "+20" one should predict unfavorable result. At the sum of "-13" prediction should be stated upon as favorable and at "-13" up to "+20" - prediction is considered to be doubtful.
EFFECT: higher accuracy of prediction.
2 ex, 3 tbl