Myelofibrosis associated with tuberculosis; a report of four cases

Myelofibrosis (fibrotic bone marrow and, usually, an increase in megakaryocytes) is characterized by generalized pains, weakness, loss of weight, enlargementof the liver and spleen and a leuko-erythroblastic anemia.

Four cases of myelofibrosis associated with generalized tuberculosis have beenreviewed in detail. Autopsy examination of the 4 cases revealed acute, caseatingtuberculosis which was considered to be responsible for the bone marrow and generalized fibrosis observed. A similar type of tuberculosis occurred in 7 of 91 casesof myelofibrosis reveiwed in the literature. The pathogenesis of myelofibrosis associated with tuberculosis is discussed.

In the diagnosis of this syndrome, attention is called to the importance of obtaining a bone marrow biopsy and making a complete bacteriologic and pathologicstudy of this tissue for tuberculosis.

The 4 tuberculous cases here reported as compared with 5 cases of idiopathictype, are younger, have hyperpyrexia, less splenic but greater lymph node enlargement and run a shorter course before death.

     

Chemotaxis of Gametes: A Diffusion Approximation

Sexual attraction of male gametes toward females of many brownalgae species is induced by diffusible pheromones, which leadto a chemotactic modification of the loop-like 2-dimensionalswimming paths of the males. We propose a stochastic model andanalyse a suitable diffusion approximation in order to calculatequantities as the aggregation factor, the rotational flux component,and the mean mating time.     

The Basis for Activity Controlled Rate Variable Cardiac Pacemakers: An Analysis of Mechanical Forces on the Human Body Induced by Exercise and Environment

We conducted tests on six healthy volunteers and six pacemaker patients. With the aid of three straight line frequency acceleration pickups attached to the body, the mechanical signals were recorded on the three axes during different activities. Along with standardized exercise on bicycle and treadmill ergometers, we tested the influence of household activities and interference influences. The results were analyzed in terms of the amplitude and frequency content of the signals. For walking activities, we found a signal amplitude increasing in a largely linear fashion with the walking speed, the signal amplitudes being approximately twice as high on the vertical axis as on the other two axes. Exercise on the bicycle ergometer produced mechanical signals of clearly lower amplitude than comparable walking activities. The Fast-Fourier analysis showed amplitude peaks in the low frequency range of 1 to 4 Hz for all forms of physiological exercise, while interference influences showed amplitude peaks mainly in the range above 8 Hz. The use of a straight line-frequency acceleration pickup and a corresponding low pass filter might be a way of reducing the effect of unphysiological interference influences on an activity controlled pacemaker system. A sensor measuring on the horizontal axis appears to be the most favorable compromise for the various types of exercise. However, due to the considerable difference in signal amplitude for different types of exercise of the same intensity, an activity controlled pacemaker system cannot entirely meet metabolic conditions and requirements.     

Differences Between Atrial Single Chamber Pacing (AAI) and Ventricular Single Chamber Pacing (VVI) with Respect to Prognosis and Antiarrhythmic Effect in Patients with Sick Sinus Syndrome

STANGL, K., ET AL.: Differences Between Atrial Single Chamber Pacing (AAI) and Ventricular Single Chamber Pacing (VVI) with Respect to Prognosis and Antiarrhythmic Effect in Patients with Sick Sinus Syndrome. Several studies suggest different effects of atrial (AAI) and ventricular single chamber pacing (VVI) for sick sinus syndrome with respect to the suppression of atrial tachycardias and to the prognosis. With this aspect in mind, we studied 222 patients with sick sinus syndrome, 110 of whom had been supplied with AAI systems, and 112 with VVI systems, in the period from January 1978to December 1986. The mean observation period was 53 ± 28 months. The cumulative 5-year survival rate was not significantly different in the two groups. After subgroups with comparable underlying diseases had been differentiated, patients with coronary heart disease showed a significantly higher survival rate (p < 0.05) under AAI pacing, and the same was shown for patients with no underlying heart disease (p < 0.02). The incidence of chronic atrial fibrillation was 6% in the AAI group and 19% in the VVI group. Patients with preexisting atrial tachyarrhythmias showed the lowest incidence of chronic atrial fibrillation under AAI pacing. Under VVI pacing this incidence was a function of the basic rate of the pacemaker systems. In conclusion, the pacing mode seems to have a prognostic importance in spite of all methodological difficulties. A suppressive effect of AAI pacing on atrial dysrhythmias can also be assumed.     

Temporal Relationship Between Exercise and QT Shortening in Patients with QT Pacemakers

The present study was undertaken to examine the temporal relationship between exercise and QT interval shortening as one of the principal determinants for the functioning of QT pacemakers. Ten patients (mean age of 72.6 years) with implanted QT pacemakers were subjected to supine bicycle exercise with two different slopes, 90% and 80%. The QT interval as seen by the pacemaker was monitored by telemetry and stored on magnetic tape. After the beginning of exercise QT prolongation of a few msec occurred up to 40 sec in most patients. The earliest QT shortening of 4 msec was noted after 63.4 sec with 90% slope and 75.7 sec with 80% slope. The difference was not significant. The further time course was dependent on slope and pacemaker algorithm. Maximal QT shortening was 65.9 msec with 90% and 69.8 msec with 80% slope. It was seen 29.2 sec after termination of exercise with 90% slope and 69.5 sec with 80% slope (P < 0.05). There was no correlation of the measured delays with age. Earliest rate response in QT driven pacemakers is determined by earliest QT shortening on one hand and by the slope setting of the pacemaker on the other, where the limiting parameter appears to be QT shortening, which occurs after the first minute of exercise.     

Internal Cardioversion of Atrial Fibrillation with a Single Lead Configuration in a Patient with Massive Diaphragmatic Herniation

An anatomically related circumstance is reported as indication for the internal low energy Cardioversion instead of an external approach. A new single lead electrode configuration is described.     

Determining mandibular condyle and ramus height with the help of an Orthopantomogram®– a valid method?

summary The asymmetry of condylar and rami heights was determined from Orthopantomograms® of 25 macerated skulls and compared with the results of the 'true' values obtained by direct measurements of the skulls. The correlation between the two measuring methods was low.