Brain abscesses due to Streptococcus milleri occurring in 2 previously healthy children are reported. Both children had evidence of liver involvement and both responded well to antibiotic treatment.
A program derivation is said to be polytypic if some of its parameters are data types. Polytypic program derivations necessitate a general non inductive definition of ‘data type’. Here we propose such a definition: a data type is a relator that has membership. It is shown how this definition implies various other properties that are shared by all data types. In particular, all data types have a unique strength, and all natural transformations between data types are strong.
Thirty-five horses that had bone sequestration as a consequence of limb wounds were examined clinically and radiographically. It is possible to diagnose bone sequestra as early as 10 to 15 days after injury. Periosteal defects and infection appear to be the basis for bone sequestrum formation. The early radiographic signs of bone sequestration and progress to mature sequestrum formation are described. Treatment is the surgical removal of the sequestrum. In the presence of equine limb wounds in which the periosteum may have been damaged, it is advisable to radiograph the limb at the initial examination and again in 10 to 15 days.
SUMMARY The migration of a pacemaker from the subrectus area of the abdomen to the lower pelvic region, causing pacemaker electrode extension and eventual fracture in a child of 2 years, is reported. Subsequent analy sis revealed that breakage may have been augmented by fibrous adhesion around the electrode at a site distal to the pacemaker rather than ten sion caused by the mass of the pace maker alone. Two surgical approaches, each depen dent on the electrode placement, are favoured when implanting a cardiac pacemaker,'-3 viz. the endocardial and epicardial approaches. Pacemaker migration following implantation is occasionally seen in patients who have undergone endocar dial electrode introduction via the subclavian or the cephalic vein, when the pacemaker is normally implanted in the region of the lateral chest wall behind the pectoral fold. This applies especially when pacemakers large in size and mass migrate from the pec toralis to an area below the axilla. In these instances, migration is invariably due to weight dislodgement and is more commonly seen in obese and large-breasted patients who have little supportive tissue to encapsulate the pacemaker. With recent advances in electronic technology, pacemakers are much smaller in volume (lO cc) and mass (25 g), and the incidence of weight dis lodgement has decreased considerably. Displacement of the pacemaker when the electrode is attached to an epicardial surface is comparatively rare. The pacemaker is commonly implanted above or below the rectus sheath, the choice usually governed by
'%3e%3cpath fill='%23012169' d='M0 0v30h60V0z'/%3e%3cpath stroke='%23fff' stroke-width='6' d='m0 0 60 30m0-30L0 30'/%3e%3cpath stroke='%23C8102E' stroke-width='4' d='m0 0 60 30m0-30L0 30' clip-path='url(%23b)'/%3e%3cpath stroke='%23fff' stroke-width='10' d='M30 0v30M0 15h60'/%3e%3cpath stroke='%23C8102E' stroke-width='6' d='M30 0v30M0 15h60'/%3e%3c/g%3e%3c/svg%3e)
