Graphic Trace Research Articles

Some Effects of Metal Cations on Blood Coagulation

SummaryThe action of some metal cations on blood coagulation was studied by means of t.e. graphic tracings. They exerted a delaying effect on coagulation process, as shown by the r increase and ma decrease. It is probably due to the formation of complex and reversible compounds. Adding a strong chelating agent, EDTA, caused perceptible reversal of the cation activity.

Determination of focusing properties of solar collectors by an integral formula

Abstract An analytical procedure is derived for determining the distribution of energy at the focal plane of a mirror such as is used in a solar collector system. The method is a general one that permits any shape of emitting and reflecting surfaces, and is an analytical equivalent of the conventional ray-tracing procedure of geometrical optics. The advantage provided is that the calculation of intensity of collected radiation at a given point can be performed on a digital computer in less than 15 seconds whereas one man-week is required for graphical ray tracing. The solution takes the form of an exact double integral which gives directly the intensity of reflected radiation at any given point for an arbitrary Lambert surface emitting at least partially to an arbitrary reflecting surface. The double integral has been programmed on a digital computer to evaluate the performance of solar collectors.

Uterine contractions during labor in myotonic muscular dystrophy

Graphic tracings representing uterine contractions during labor in a patient with myotonic muscular dystrophy are presented. The patient had a clinically inert labor requiring oxytocin stimulation and tocodynamometer tracings taken before and after stimulation are compared. The graphic representation of the uterine contractions suggested a prolonged plateau phase of relaxation, which had not been previously reported, and this relaxation phase appeared to be shortened by the oxytocin stimulation.This is also a case of cardiac arrest at 15 weeks' gestation, with survival of mother and delivery of an apparently normal infant.

Uni-axial pantograph

A description is given of a simple and effective drafting instrument for changing the scale of a graphical trace along one axis only, leaving the other axis unaltered.

Rate of recovery of functioning in cats with rostral reticular lesions; an experimental study.

Recent studies, experimental and clinical, emphasize that damage to the rostral brain stem leads to derangement of consciousness, the site of emphasis being the mesial tegmentum of the midbrain. Earlier Bremer 2 stressed the similarity between sleeping cats and those with cerveau isol~ (midbrain transection) and attributed the former to interruption of the tonic drive propagated rostrally over the great afferent paths. The cerveau isol~ preparation also showed the spontaneous spindling of the sleep electroencephalogram . Lindsley, Bowden and Magoun s added selective sections of the lemniscus to enc~phale isol5 (acute C1 transection) preparations. This did not convert the activation tracing characteristic of the enc~phale isol5 to the cerveau isol~ type. However, lesions that instead destroyed sub- and hypothalamus from optic chiasm to mammillary bodies or anterior midbrain did produce a sleep tracing. Additionally, Lindsley et al2 studied the effects of chronic lesions. In animals with lesions in the ponto-midbrain tegmentum, midbrain tegmentum, hypothalamus, and junction between hypothalamus and thalamus, the common behavioral result (variable in degree depending upon site and extent of the lesion) was a postoperative somnolence or lethargy in which the animal displayed little or no spontaneous activity of a purposive sort, and seemed unaware of ordinary environmental stimuli. The animal with a midbrain tegmental lesion blocking much or all of the rostral end of the reticular activating system lay on its side with eyes closed as if deeply asleep during its ~l-day survival period. By contrast, in ~ anireals in which the periaqueductal gray was injured an approximation of normal sleeping-waking behavior was regained. Two others, with lateral mesencephalic lesions which spared the mesial tegmentum, became able to stand and walk again and showed activation of the electroencephalo graphic tracing. Experiments on 9 monkeys reported by French and Magoun 6 appeared generally to confirm these results so far as destruction of the reticular activating system and the associated behavioral deficits are concerned.

Studies in pulmonary ventilatory function: I. Vital capacity, first one-second capacity, and forced respiratory curves in patients with asthma: Comparative evaluation of methods

1. 1. Time and volume measurements of ventilatory function have been obtained on 211 subjects, utilizing Gaensler's apparatus and graphic tracings of forced maximal expiration and inspiration by means of a Benedict-Roth spirometer and rapidly moving kymograph with timer. These determinations were obtained before and twenty minutes after the subcutaneous injection of epinephrine. 2. 2. A comparison of the ventilatory function of normal, symptom-free asthmatic, and active asthmatic subjects is given by relating the values for the mean determined vital capacity, the mean first one-second volume, and the mean rate of flow to the mean predicted vital capacity of each group, and by relating these expressions of the predicted vital capacity of the symptom-free group and active asthma group to that of the normal group. The results of these comparisons suggest that the relationship of the forced maximal vital capacity and time of performance of the expiratory ventilatory effort, as expressed by the mean rate of flow, is a more complete reflection of the ventilatory state than either vital capacity or the first one-second volume measurement, especially in the group of men and women over 40 years of age. The mean rate of flow, expressed as per cent of mean predicted vital capacity, was 5.9 per cent for forced inspiration and 4.12 per cent for forced expiration in the group of normal subjects. In the symptom-free asthmatic group, it was 6.4 per cent for forced inspiration and 2.46 per cent for forced expiration. In the active asthmatic group, it was 5.1 per cent for forced inspiration and 1.27 per cent for forced expiration. A comparison of similar studies of the inspiratory phase of forced respiration, utilizing volume, total time, and mean rate of flow measurements, reveals too little variation in observations between groups for statistical significance.

A Comparison of Electrokymography and Roentgenkymography in the Study of Myocardial Infarction

The authors present two cases of myocardial infarction to demonstrate that electrokymography is superior to roentgenkymography as a method for detecting localized areas of myocardial damage. This superiority is based principally on greater ease of exploration of the ventricular pulsations, clearer delineation of the kymographic curve as a result of greater magnification, and more accurate analysis of the phases of the cardiac cycle by simultaneous recording and integration with other graphic tracings.

A new electrical weight barograph

AbstractAn account is given of a new weight barograph which resembles that of Sprung in principle but differs almost entirely in detail. Its mechanism is driven electrically, and provides not only a clear graphical trace of the pressure but a printed numerical record of its value every hour. The usefulness of this lies not so much in facilitating the abstraction of the data from the charts as in adding materially to the accuracy, for changes in humidity have a decided effect on the width of the paper, and may under extreme conditions cause an error of a millibar in the trace.The barometric tube and a counterweight hang from the ends of a beam, pivoted a t its centre, and on the beam is a rolling weight; when the beam is slightly tilted by a change of pressure a contact is made which through a sensitive relay brings into operation an electric motor. This moves the rolling weight until equilibrium is again reached and the position of the rolling weight controls both the trace and the number printed.After a discussion of the fundamental principles the mode of construction is described in some detail, and finally the methods of adjustment and the compensation for temperature.

Las arritmias en clínica.

Dr. Battro has again scored by presenting an excellent book. In this volume he has thoroughly gone into the subject of the arrhythmias from the diagnostic, prognostic and therapeutic standpoints. The general anatomy of the heart and especially the blood supply is well illustrated. His brief discussion of the physiology and the many graphic tracings are both timely and illustrative of the thoroughness with which the subject is presented. Basically the book is divided into chapters dealing with the arrhythmias under the following headings: (1) chronotropic arrhythmia, (2) bathmotropic arrhythmia, (3) dromotropic arrhythmia, (4) fibrillation and flutter and (5) inotropic arrhythmia. The bibliography is thorough, covering fifty pages, and includes a large percentage of references to American authors.

EXCESSIVELY RAPID HEART RATES

The ventricles of the human heart have rarely been observed to pulsate at a rate approaching 300 per minute. Only sixteen cases in which there was a ventricular rate of 280 or over were found in the literature (table 1). In ten of these the rate was confirmed by graphic tracing; in the remaining six the count was by stethoscope only. A ventricular rate of 300 beats per minute was recorded electrocardiographically in four cases. In no case was an electrocardiogram published showing a rate that exceeded 300 per minute. Werley1published a polygram presenting a ventricular rate of 307. Blackford and Willius2stated that a patient having auricular flutter with a two-to-one block entered their office during a paroxysm of one-to-one response which lasted nearly two hours. A heart rate of 320 was counted by means of the stethoscope. Later during the attack an electrocardiogram was taken

Contribution to the treatment of so-called “true asthma”: Dudan, A.: Schweiz. med. Wchnschr. 61: 137, 1931

1.1. Time and volume measurements of ventilatory function have been obtained on 211 subjects, utilizing Gaensler's apparatus and graphic tracings of forced maximal expiration and inspiration by means of a Benedict-Roth spirometer and rapidly moving kymograph with timer. These determinations were obtained before and twenty minutes after the subcutaneous injection of epinephrine.2.2. A comparison of the ventilatory function of normal, symptom-free asthmatic, and active asthmatic subjects is given by relating the values for the mean determined vital capacity, the mean first one-second volume, and the mean rate of flow to the mean predicted vital capacity of each group, and by relating these expressions of the predicted vital capacity of the symptom-free group and active asthma group to that of the normal group. The results of these comparisons suggest that the relationship of the forced maximal vital capacity and time of performance of the expiratory ventilatory effort, as expressed by the mean rate of flow, is a more complete reflection of the ventilatory state than either vital capacity or the first one-second volume measurement, especially in the group of men and women over 40 years of age. The mean rate of flow, expressed as per cent of mean predicted vital capacity, was 5.9 per cent for forced inspiration and 4.12 per cent for forced expiration in the group of normal subjects. In the symptom-free asthmatic group, it was 6.4 per cent for forced inspiration and 2.46 per cent for forced expiration. In the active asthmatic group, it was 5.1 per cent for forced inspiration and 1.27 per cent for forced expiration.A comparison of similar studies of the inspiratory phase of forced respiration, utilizing volume, total time, and mean rate of flow measurements, reveals too little variation in observations between groups for statistical significance.

Cellular processes in the latent period

Guinea-pigs were passively sensitized by the injection of the serum of a rabbit highly immunized to horse serum. Before the latent period had expired, i. e., during the first 12 hours, the guinea-pig was killed, and the horns of the uteri were suspended for graphic tracing. One horn was immediately tested by means of horse serum. If it gave no response, the preparation was at once thoroughly washed, and the experiment continued. Both horns were kept in Locke's fluid for several hours. At the end of this time, both were again tested against horse serum. Both regularly responded with contractions, but that yielded by the previously tested horn was much less vigorous than by the other. The latter fact shows that the preliminary test by horse serum had partially desensitized the antibodies.The following conclusions are drawn:1. The cells absorb antibody from the blood during the first stage of the latent period. These antibodies can unite with the antigen, and the cells can thus be desensitized, but that this...

STUDIES IN THE REFLEXES OF THE GUINEA‐PIG. I. THE SCRATCH‐REFLEX IN RELATION TO “BROWN‐SÉQUARD'S EPILEPSY.”

1. Of 20 guinea‐pigs 14 have survived the operation of resection of a portion of the right great sciatic nerve for a sufficient length of time, and each one of these has exhibited the movements described by Brown‐Séequard as “epilepsy.” None of these have shown “spontaneous” attacks or the condition of “blepharospasm.”2. The movements were evoked by stimulation of a special area of the skin, the adequate stimulus being mechanical pressure. Stimuli consisting of loud sounds, the vibrations of which ranged between 32 and 16,000 per second, of a bright beam of light directed into the eye, and of a warm beam of light directed on to various parts of the special area of skin, were inadequate. Electrical stimuli given in the form of galvanic shocks were inadequate, as also possibly they were when given in the form of rapid double faradic shocks.3. The boundaries of the special zone of skin are larger than those given by Brown‐Séquard. It almost invariably extends further back than the posterior border of the scapula, while it may extend as far forward as the border of the nostril and the edge of the lower lip in the middle line.4. Changes in the condition of this area, and also in that of the lower limb of the side of the lesion, similar to those described by Brown‐Séquard, were observed.5. The movements, which consist of tonic contraction of the muscles of the neck and back, and of clonic movements at the hip‐joint, occur in two stages. In the first of these the movements are confined to the side of the lesion, while in the second they spread to the opposite side.6. The rhythms of the clonic movements observed lay between the limits of 8 and 16 beats per second. The rhythm was slower in the larger animals. It was also slower towards the end of one reflex, and varied when the reflex was evoked from different points in the special area.7. The clonic movements, as studied in graphic tracings, show a marked resemblance in many of their features to the scratch‐reflex observed in the spinal dog.8. They differ from this reflex in the overflow to the opposite side, and in the phenomenon of alternation, as well as in the degree of the tonic factor.9. Once the clonic movements have appeared, they become progressively more extensive up to a certain point as the condition persists. The excitatory value of the maximal stimulus rises.10. The clonic movements may be inhibited by stimulation of the skin on the abdomen of the opposite side by mechanical pressure. In the early stages this inhibition comes on rapidly, but persists for some time after the cessation of the inhibiting stimulus. In the later stages it is established less rapidly, but lasts a shorter time after the stimulus has stopped. Towards the end of a long reflex response the inhibiting stimulus may only affect the clonic movements by slowing the rate of the beats. When the inhibition of the clonic movements is complete, there is also an inhibition of the tonic contraction of the muscles of the side and hip.

Physical Notes

AN attempt is made in L'Electricité by M. C. E. Séguin, fils, to claim for France the honour of the invention of the phonograph; firstly, by the plea that M. Léon Scott (who died only last July) patented the instrument under the name of the phonautograph in 1857, and secondly, by the statement that M. Charles Cros deposited before the Académie des Sciences, in April, 1877, seven months before the date of Edison's patent, a sealed packet describing the possible reproduction of sounds from recorded traces. In justice to Mr. Edison, we can hardly admit the validity of either of these claims. The phonautograph of M. Scott merely recorded the graphic traces of vibrations in sinuous scratches upon a smoked surface, which, therefore, was useless for the purpose of reproduction of the sounds; and, moreover, Dr. König, who worked upon the instrument with M. Scott, and perfected it, has stated to us most candidly that the idea of reproducing the sounds from the recorded traces never occurred either to M. Scott or to himself; and that neither of them attempted or proposed to obtain graphic traces in hollows and ridges in tinfoil or soft metal, or otherwise than as plane curves. And as for the claims of M. Cros, we have yet to learn that he constructed an actual phonograph, or that his sealed packet contained any descriptions of a sufficiently detailed of practical nature to enable any instrument to be made from them.