There are now well-documented cardiac complications of COVID-19 infection which include myocarditis, heart failure, and acute coronary syndrome resulting from coronary artery thrombosis or SARS-CoV-2-related plaque ruptures. There is growing evidence showing that arrhythmias are also one of the major complications. We report two patients with no known history of cardiac conduction disease who presented with COVID-19 symptoms, positive SARS-CoV-2 infection, and developed cardiac conduction abnormalities. Cardiac conduction system disease involving the sino-atrial (SA) node and atrioventricular (AV) node could be a manifestation of SARS-CoV-2 infection.

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As a consequence of nascent technology, the 19th century witnessed a profound change in orientation to the nervous system. For example, improved microscopy in the first half of the 19th century allowed high magnification without blurring. The subsequent observation of nucleated cells led to the identification of individual brain cells. Philosophical changes in approach to the natural sciences took their lead from those applied to physical observations. The Ukrainian anatomist and histologist, Vladimir Alekseyevich Betz (1834-94) played a pivotal role in reshaping scientific and philosophical approaches to the brain, connecting cerebral localization, function and brain microstructure. Betz revolutionized methods of cell fixation and staining. Sometimes his efforts yielded enormously complicated technological improvements. Betz's greatest contribution, however, was connecting his discovery of the function of giant pyramidal neurons of the primary motor cortex ('cells of Betz') with the cortical organization. Considering cortical cytoarchitectonics in relation with physiological function, Betz recognized this organization in two areas: motor and sensory. He defined a functional area on histological grounds and thereby opened the way to study precise cortical areas. Betz participated in the scientific transformation of cytoarchitectonics based on macro- and microscopic studies of the cortical surface, enabling him to view the paths of nerve cells in the brain. Betz's influence allowed systemization of scattered scientific findings. The discovery of pyramidal cells was a turning point in the prevailing philosophical and scientific approach to the brain, linking cytoarchitecture, neurophysiology and cerebral localization.

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this group in particular, and perhaps patients with DS in general, show a remarkable freedom from the atherosclerosis that, in some degree, inevitably accompanies advancing age. The reasons are not clear. The finding of atherosclerosis in the non-mongol mental defectives suggests that environmental factors such as diet, composition of the water, and the absence of stress are not responsible. Furthermore, the differences between the groups cannot be explained on the basis of lipid concentrations: at the time of study both groups had lower serum lipid concentrations than a group of normal people.Of the remaining accepted risk factors, blood pressure was slightly but significantly lower in the DS group, and only two of these patients (3",,) smoked compared with 13 (19%O) of the controls. While these findings may partly explain the necropsy evidence, it is difficult to accept that they can account for the total absence of atheroma in the D S group and its presence in the controls to a degree consistent with that usually found in the general population.Probably there are unidentified factors peculiar to DS that confer a noticeable freedom from atherosclerosis. Whether these are haemodynamic or arise from a peculiarity of vessel wall morphology is speculative. It certainly appears on the present evidence that DS provides an atherosclerosis-free model that merits further study.

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Mean (+ SD) alveolar carbon dioxide tension, carbon dioxide output, and alveolar ventilation in placeboand naloxone-treated babies up to 48 hours after delivery

In seven neonates, whose mothers were given pethidine during labour, urine was collected for the first 24-40 h of life. Urinary volume and pH, and concentrations of pethidine and norpethidine in the urine were measured. Urine flow rate was low for the first 7-22 h, and then high for about 12 h. The rate of excretion of pethidine and norepethidine was approximately parallel to the urine flow rate. However, the ratio of the rate of excretion of norpethidine to that of pethidine increased with time and the concentration of norpethidine in urine decreased first and then, after 18 h, increased significantly. These findings that the neonate can metabolize pethidine, although the rate of metabolism is probably less than in the adult. The total amounts of pethidine and norpethidine excreted in the first 24 h after birth were positively related to the dose-delivery interval in the mother for intervals up to at least 5 h. From the data it is estimated that 95% of the total pethidine transferred from the mother would be eliminated by the baby by the 2nd to 3rd day after birth.