Incidence and clinical aspects of aneurysm rupture in the abdominal aorta]

On the basis of the section material of 25 years in Tartu a significant increase of the frequency of arteriosclerotic aneurysms of the aorta, especially of the abdominal aorta and its ruptures, could be established. At the same time the appearance of luetic aortic aneurysms decreased. Due to its variable symptomatology the diagnosis of the rupture of an aneurysm of the abdominal aorta is often not exactly diagnosed by the physician who is first in charge of the case. On the basis of a clinical material of 21 post-mortem examinations the diagnostics of the rupture of the aneurysm of the abdominal aorta is discussed, and the most important symptoms are emphasized. It is emphasized that an aneurysms of the abdominal aorta shall be recognized in every case allready before its rupture as the prognosis of the operation is relatively good in this stage. Since it must be reckoned with a continuous increase of the frequency of the arteriosclerotic lesions of the aorta the physician shall, too, always think of an aneurysm of the abdominal aorta when uncertain complaints of the abdomen and the back are present.     

The Evaluation of the Effectiveness of Reinforcement by Cemented-Carbide Plates in Two Design Variants of the Chisels Intended for Cultivation–Sowing Aggregates

Field tribological tests of two design variants of chisels used in the teeth of a cultivation-sowing unit were carried out in this research. A characteristic feature of the first variant of chisels was the reinforcement of their contact surface and almost the entire rake surface by plates made of cemented carbides. On the other hand, the second variant of chisels was reinforced only in the area of the blade by two plates made of cemented carbides, soldered on the rake face of the elements. The use of the first variant of chisels contributed to a significant reduction in the wear rate of elements, especially in terms of thickness and width loss. Effective reinforcement of the rake face, with relatively lower resistance to length reduction in the elements, raises doubts as to the validity of the use of cemented-carbide plates on almost the entire length of their rake face, because the applied variant of chisels contributed to a significantly higher price. However, the second variant of chisels effectively limited the intensity of the loss of the length of the elements, and the cause of the loss of their usefulness as part of the base material wear. It was found that the main wear mechanism of the cemented-carbide plates consisted of matrix removal under the influence of the finest fraction of the soil, which weakened the embedding of carbides, and then crushing or chipping of carbide grains from the matrix, whereas the dominant wear mechanisms of martensitic steel were grooving and micro-cutting.     

Relationship between the spike potentials of "local" intra-atrial and esophageal electrocardiograms of the atria and notched P wave of ECG from the body surface

The interrelationship of spike potentials of "local" intraatrial and esophageal electrograms and notched P wave of an intensified ECG recorded from the body surface was studied. It was found that the process of excitation in the region of the sinus node is reflected in the slow deviation of the P wave of intensified ECG, preceding the appearance of the P wave of an ordinary ECG recorded from the body surface. The A1 spike of a "local" electrogram reflecting the penetration of excitation into the right atrium is manifested in the form of the first notch of the P wave on an intensified ECG. The A2 spike reflecting the arrival of the excitation to the atrioventricular node is manifested in the form of a notch--the first peak of the P wave. The A1(2)) spike reflecting the arrival of the excitation to the left atrium along Bachmann's bundle is manifested as the second peak of the P wave (A1(2)). The A3 spike of the "local" electrogram reflecting the arrival of the excitation from the left atrium to the orifice of the coronary sinus is manifested in the form of the second notch of the P wave (A3).     

Pathogenetic aspects of chronic urinary tract infections

Infections of the urinary tract belong to the most frequent bacterially caused diseases. Strains of bacteria which are able to evoke an infection of the urinary tract distinguish themselves by particular properties. Hereby the existence of O- and K-antigens, the demonstration of adhesins (F-antigens), the ability of the formation of haemolysin and production of colicin V (aerobactin), the serum resistance as well the plasmid profile an important role is ascribed. The ability of uropathogenic bacteria to the adhesion to the epithelial cells of the urinary tract is significant for the development and the course of a disease. A connection is to be established between the rate of bacterial attachment of the epithelial cells and the activity of a pyelonephritis. The defence of an infection of the urinary tract takes place above all in the local area, in which cases among others the phenomenon of the antibody coated bacteria and disturbances of the formation of the secretory IgA are of interest. Various pathogenetic aspects of chronic infections of the urinary tract are discussed on the basis of reports from literature and findings of own investigations.     

The cytological characteristics of bronchoalveolar washings in chronic bronchitis

Bronchoalveolar washings (BAWs) from 30 patients with nonobstructive chronic bronchitis (CB) were examined cytologically. On the basis of the taxonomic analysis of the data on the cytological examination of the BAWs, all the observations were classified as belonging to degrees I, II and III of the cytological activity of the inflammatory process in the lungs. It was revealed that the minimal degree of the activity of the inflammatory process was characterized by a marked increase in the relative numbers of the cells of the desquamated cylindrical epithelium and destroyed cells along with a significant decrease in the proportion of macrophages and an increase in the relative count of neutrophils. The increased activity of the inflammatory process in the lungs was accompanied by a progressing increase in the proportion of neutrophils and a decrease in the relative count of macrophages and the cells of the cylindrical epithelium. Clinico-cytological analysis of the observations was also performed. The most complete and objective estimation of the degree of the inflammatory process activity in the lungs in the patients with CB was provided by the cytological indices of the BAWs.     

Understanding disorders in the regulatory cycle of the thyroid. Significance for diagnosis and therapy

In the regulating circle for the regulation of the functions of the thyroid gland interactions exist between hypothalamus, anterior lobe of the pituitary gland, thyroid gland and the concentrations of the thyroid hormone at the periphery. By means of the TRH-test the secretory work of the thyrotropic function of the hypophysis depending on the activity of the thyroid hormone can be judged. On the other hand, the T3-suppression test (radioiodine test before and after application of T3) allows a statement on the hypophyseal-thyroidal regulation. In contrast to the exclusive determination of the peripheral thyroid hormones by means of the TRH-test an etiologic differentiation of hypothyreoses and an essential improvement in the diagnosis and conduction of the therapy of thyroidal diseases and functional disturbances is made possible, as it is demonstrated at instances. By means of the T3-suppression test it is possible to establish, still under the treatment of a diffuse hyperthyreosis, whether the function of the thyroid gland is again regulated by the hypophysis or is still autonomous. Together with the result of the TRH-test decisions may be rendered on the end of the treatment or on the further course of the therapy.     

Disturbance in the function of the spinal centers in diffuse toxic goiter in children (electromyographic study)]

Peculiarities of the reflex and motor responses of the soleus muscle were studied in stimulation of the tibial nerve by stimuli of gradually increasing intensity, and also in double stimulation and against the background of contraction of the antagonistic muscles in children with diffuse goiter and in healthy individuals. In sick children an increase and a fall in the H-response amplitude with increase of the stimulation intensity occurred more rapidly than in healthy ones. A rapid restoration of the reflex response at the interval of 500 msec and greater was noted in studying the cycle of restoration of excitation of the motor cells of the anterior horn in sick children. Against the background of contraction of the antagonistic muscles the reciprocal inhibition of the reflex response of the muscle was weaker than in the healthy individuals. The data obtained led to a supposition that one of the causes of motor disturbances in case of an excess of the thyroid hormones in the organism could be a disturbance of the processes of the pre- and postsynaptic inhibition at the spinal level.     

Tests of gastric secretion in diagnosis and therapy of peptic ulcer]

A survey of the modern importance of the secretion test of the stomach for diagnostics and differential diagnostics of the gastroduodenal ulcer, for an individualising surgery of the stomach and for the testing of the success in vagotomy is given. In the epoch of the fibre endoscopy the secretion test can scarcely still contribute to the diagnostics of ulcer, but it is now as ever important as screening method for the differentiation of the Zollinger-Ellison-syndrome. The decision on the size of an individual surgical intervention for the treatment of the peptic ulcer should also be based on the result of the secretion test. The usual control of the success of vagotomy by means of the insulin test has its problems.     

Organotropicity and the dynamics of the clearance of exogenous labelled TSH from the blood under conditions of stimulation and blockade of the thyrotropic function of the hypophysis]

Experiments were conducted on male Wistar rats. Incorporation into the kidney, the liver and the thyroid gland of I131-TSH and its elimination from the blood was studied. The rate of I131-TSH elimination from the blood plasma varied depending on the level of the endogenous TSH in the circulating blood of the recipient rats. The half-elimination period of the I131-TSH from the blood plasma of the intact rats constituted 10.4 minutes. In these animals the labeled hormone accumulated in the thyroid gland only 30 minutes after its administration. In case of an increase of the blood level of endogenous TSH following thyroidectomy the period of half-elimination of the I131-TSH from the plasma fell to 3.6 minutes; with reduction of the endogenous hormone level due to the block of the hypophysial secretion by triiodothyronine the period of the I131-TSH half-elimination rose to 39.4 minutes. In the latter case the labeled hormone failed to be incorporated into the thyroid gland. A conclusion was drawn on a possibility of assessing the level of the thyrotropic activity of the hypophysis on the basis of the changes in the period of the I131-TSH half-elimination from the blood plasma of the recipient animals.     

Analysis of Deformation and Prediction of Cracks in the Cogging Process for Die Steel at Elevated Temperatures

In this paper, an analysis of a three-dimensional state of strain and stress in the case of the hot cogging process of X32CrMoV12-28 die steel with the application of the finite element method is presented. The results of the investigations connected with the simulation of the kinematics of metal flow and thermal phenomena are presented, accompanied by prognosing the formation of ductile fractures in the course of the hot cogging process conducted with the application of three different shape tools and of a proposed deformation criterion of the loss of cohesion. The applied anvils were found to be highly effective in the aspects of distribution of effective strains and stresses, absence of tensile stresses in the axial zones of a forging, and also of a significant thermal stability in the internal layers of a deformed material. The developed course of changes in the deformation of the damage factor in the case of forging in the investigated anvils renders it possible to predict the situation and the phase of deformation in which the loss of cohesion by a deformed material will occur. The comparison between the predicted and the experimental results showed a good agreement.     

Scanning electron microscopy of injection replicas of the cardiac microvessels

The paper concerns three-dimensional study of the organization of the subepicardial network of the blood and lymphatic microvessels of the heart with the aid of scanning electron microscopy of the injected replicas. It is established that the arterioles have regular orientation of the imprints of the nucleus-containing zone of endotheliocytes. The capillaries belonging to the subepicardial network form a thick mesh and are strictly oriented along the muscular bundles. There is no characteristic relief on the surface of the capillaries. The study of the relief of the post-capillary venules made it possible to record different orientation of the imprints of the nuclei-containing zones of endotheliocytes on their surface. The study of structure of "leaks" formed as a result of leaking of resin from the venular segments of the bed enabled one to elicit their passage into the lymphatic capillaries. The latter are represented by flattened tubes, placed over the blood vessels.     

The state of the nuclear apparatus of the thyroid gland under conditions of hypofunction of the sympathetic division of the nervous system]

A study was made of the effect of the sympathetic portion of the nervous system on the thyrocyte metabolism. Such morphological criteria as the volume of the thyrocyte nuclei, the amount of DNA in them and structural analysis were used. Three volumetric classes of the nuclei with a different morphological picture were detected in control animals. In depression of the sympathetic portion of the nervous system by administration of antibodies to the growth factor of the nerves there was seen a reduction of the mean nuclear volume and displacement of the volumetric classes in the direction of increase in the quantity of smaller nuclei; electron microscopic studies demonstrated changes in the shape and structure of the nuclei. There were no variations in the amount of DNA.     

The Influence of Specimen Geometry and Loading Conditions on the Mechanical Properties of Porous Brittle Media

Dynamic tests of fine-grained fired dioxide-zirconia ceramics under compression under uniaxial stress conditions were carried out. The influence of the specimen length on the obtained strength and deformation properties of ceramics is investigated. The thickness of the specimen has a significant impact on the course of the obtained dynamic stress–strain diagrams: short specimens have a much more sloping area of active loading branch. The main contribution to the modulus of the load branch resulting from tests of brittle porous media is made by the geometry of the specimens and the porosity of the material. When choosing the length of specimens for dynamic tests, the optimal geometry of the tested specimens is preferable in accordance with the Davies–Hunter criterion, when the contributions of axial and radial inertia are mutually compensated, and the contribution of the effects of friction in the resulting diagram is minimal. When choosing the geometry of specimens of brittle porous media, the structure of the material should be taken into account so that the size of the specimen (both length and diameter) exceeds the size of the internal fractions of the material by at least five times.     

Complications of cardiac pacemakers]

Since the number of patients with pacemakers increases and the further decentralisation of the care of these patients is planned the survey has the purpose to inform as many physicians as possible about the complications of the pacemaker therapy. In the several paragraphs the problems of the regular and anticipated exhaustion of the battery, defects of the electronic constituents of the pacemaker, fracture of the cable, dislocation of the electrodes, disturbances of the transmission between endocardium and myocardium, disturbances of rhythm under pacemaker-therapy, disturbing influences by intra- and extracorporal causes, surgical complications and implantations in the false place are reported on. Knowledge and early recognition of the complications in the pacemaker-therapy will furthermore favourably influence the long-term prognosis of this group of patients.     

Effect of cholecystectomy for gallstones on the surface of the papilla of Vater and the diameter of the common bile duct

BACKGROUND AND STUDY AIMS: To date, little is known about changes in the size of the papilla of Vater in patients with gallstones. Most of the research concerning these patients has investigated changes in the diameter of the common bile duct and pressure in the sphincter of Oddi region. The latest research has not confirmed the prevalent opinion that the common bile duct dilates after cholecystectomy; moreover, knowledge about changes in the form and size of the papilla of Vater remains poor. The aim of our research was to measure the surface of the papilla of Vater and the diameter of the periampullary pancreatic part of the common bile duct before surgery, then 3 months and 6 months after surgery, using endoscopic ultrasound. PATIENTS AND METHODS: In patients with symptomatic gallstones but with no evidence of cholestasis or stones in the common bile duct, the surface of the papilla of Vater and the diameter of the periampullary pancreatic part of the common bile duct were measured before surgery by endoscopic ultrasound. In the postoperative period, measurements were repeated in patients with an early occurrence of nausea, distension, bloating and pain in the upper abdomen and in patients without any symptoms in the same time period. The surface of the normal papilla of Vater and the diameter of the periampullary pancreatic part of the common bile duct were determined in healthy subjects. RESULTS: In all the patients included in our study, the surface of the papilla of Vater was enlarged before surgery and, after 3 months, was even larger. However, after 6 months, it was practically the same as before surgery. The diameter of the periampullary pancreatic part of the common bile duct before surgery and 6 months after surgery was within normal limits. However, a statistically significant and transient increase in the diameter was noticed in the third month after cholecystectomy. The results were almost the same for symptomatic and asymptomatic patients. CONCLUSION: In patients with symptomatic gallstones, the surface of the papilla of Vater is increased while the diameter of the periampullary pancreatic part of the common bile duct is normal. Cholecystectomy is an intervention that causes an additional transient increase in the surface of the papilla of Vater and a transient increase in the diameter of the periampullary pancreatic part of the common bile duct. The surface of the papilla of Vater does not reach normal values but the diameter of the periampullary pancreatic part of the common bile duct is normalized 6 months after surgery. There is no relation between clinical disorders and changes in the morphology of the papilla of Vater and the periampullary pancreatic part of the common bile duct after cholecystectomy.     

Studies of human serum and lung-tissue oxacillin levels

After the intramuscular administration of 500 mg oxacillin (oxacillin-chinoin) the serum level and the level of the pulmonary tissue of 15 patients operated on account of different diseases of the respiratory tract were determined by means of the agar diffusion method. In the first hour the serum level showed the average value of 11.8 mcg/ml, the level of the pulmonary tissue was 2.4 mcg/g. 60-120 minutes after the administration the serum level rapidly diminished, the decrease of the level of the pulmonary tissue was smaller, i.e. oxacillin was more rapidly excreted from the serum than from the pulmonary tissue. Taking into consideration the minimum inhibition concentration of oxacillin on the basis of our results we are of the opinion that oxacillin is suitable for the treatment of gram-positive oxacillin-sensitive infections of the lungs.     

Applications of contrast echocardiography in the acute phase of myocardial infarction]

The present interest in myocardial contrast echocardiography is related to the development of new contrast agents which can be used intravenously and the perfection of new echocardiographic technologies. Amongst the potential applications of this technique, the study of myocardial perfusion in the acute phase of myocardial infarction is one of the most promising as shown by the experience acquired over several years with intracoronary contrast echocardiography. It allows assessment of the extent of the zones at risk before recanalisation, the presence of collateral vessels and, above all, the quality of myocardial reperfusion. The demonstration of the absence of effective reperfusion of the myocardial microcirculation, or the phenomenon of no-reflow, is one of the main advantages of contrast echocardiography and has been identified as an important independent prognostic factor. This technique could therefore become essential in the evaluation of methods for reducing the extent of microvascular damage. Although many questions remain unanswered about the ideal methods of performing and analysing intravenous contrast echocardiography, the preliminary results confirm the potential of the technique in non-invasive evaluation of myocardial reperfusion in the acute phase of myocardial infarction.     

Walter Gaskell and the understanding of atrioventricular conduction and block

Walter Holbrook Gaskell was a nineteenth-century British physiologist whose investigations from 1874 until 1889 became central to our current understanding of cardiac physiology. His many cardiac contributions include the following: 1) the recognition of certain inherent properties of cardiac muscle; 2) the experimental proof that led to the acceptance of the myogenic theory of the origin of the heartbeat; 3) the mapping of the anatomy of the sympathetic nervous system; 4) the understanding of the dual autonomic control of the heart; 5) the discovery of the vasodilating effect of sympathetic stimulation on blood flow through skeletal muscle arteries; and 6) the introduction of the concept of heart block. Gaskell's elucidation of the sequence of cardiac contraction and atrioventricular block and his concepts of rhythmicity, excitability, contractility, conductivity and tonicity provided the physiologic explanation necessary for the future understanding of cardiac rhythm disturbances.