PubMed Health⌕ Search

Biomedical subjects

H Verbiest

Publications and source records attributed to H Verbiest.

At least 19 recordsLinked to original sources
PubMed1989

Isolated spinous process deviation. A pitfall in the interpretation of AP radiographs of the lumbar spine.

A new type of spinous process deviation is described. This variant may cause confusion in the interpretation of anteroposterior (AP) radiographs of the lumbar spine. In the literature, two types of lumbar spinous process deviation (SPD) have been described: 1) SPD due to rotation of the entire vertebra (as in rotatory scoliosis and degenerative arthritis), and 2) SPD as a consequence of developmental asymmetries of the neural arch. The present study demonstrates that spinous process deviation in the AP radiograph is not a reliable diagnostic guide. The authors' quantitative morphologic analysis of computed tomographic (CT) sections of over 200 lower lumbar vertebrae in vivo revealed a third type of SPD, namely isolated deviation of the spinous process, ie, deviation without any associated rotation or asymmetry of the vertebral body or arch. Since the oval shadow cast by the spinous process in AP radiographs is caused by its tip, rather than by its base (as was demonstrated by in vitro tests), it is concluded that the position of the spinous process shadow in AP radiographs cannot be used as a reliable landmark to differentiate between the three types of SPD. This is only possible by means of a CT examination.

Diagnosis, Differential↗
PubMed1985

Morphometry of lower lumbar vertebrae as seen on CT scans: newly recognized characteristics.

Transaxial computed tomographic (CT) sections represent a new approach to vertebral morphometry, allowing certain measurements to be made in vivo for the first time. The cross-sectional morphology of the bodies and pedicles of L3, L4, and L5 was studied in a series of 213 vertebrae. This revealed that the pedicles of L5 arise more laterally from the body of L5 than from L3. Further, the lateral surfaces of the L5 body are inclined obliquely, unlike those of L3. L4 is transitional in form between L3 and L5, more closely resembling the former. This morphology explains the fact, hitherto unnoticed, that the lateral outlines of the pedicles and the lateral borders of the body of L5 are not normally imaged on plain anteroposterior radiographs. It is evident that pathologic changes of the lateral borders of the body of L5 may be invisible also. In cases of transitional vertebrae in the lumbosacral region the presence or absence of the lateral outlines of the pedicles and of the lateral borders of the vertebral body may be of help in identifying the vertebrae on conventional projections.

Adolescent↗
PubMed1980

Stenosis of the lumbar vertebral canal and sciatica.

Stenosis of the vertebral canal is a form of compressive stenosis in contrast to transport stenosis of vessels or other channels. The concept, definition and pathomorphological properties are discussed. As it is a form of compressive stenosis, the diagnosis is based on measurements of diameters rather than of cross-sectional surfaces. The biomechanical action of compressive stenosis is compression of the fixed living content at two opposite sites or at all sites. The special properties of sciatica in stenosis are described and presented in tabular form. Some properties of neurogenic intermittent claudication (I. Cl.) in the presence of stenosis are discussed. There is a predominance of sciatica at rest and of motor weakness during walking. The mechanism of neurogenic I. Cl. is obscure. Stenosis of the lumbar vertebral canal is one of the conditional determinants of I. Cl. The data presented in this paper demonstrate, however, that stenosis is not an absolute determinant of I. Cl. and that its production depends on the combination with other determinants. The theory is advanced that other determinants may be related to changes in the caudal nerve roots due to either constitutional properties or to subclinical changes induced by ageing and chronic wear and tear, and compression and traction in the area of stenosis during various bodily activities. Suppression of sciatica during I. Cl. is a phenomenon which is particularly difficult to explain.

Anthropometry↗
PubMed1978

Isozymes of pyruvate kinase from human brain, meningiomas, and malignant gliomas.

Pyruvate kinase isozymes were studied in normal brain tissue (both fetal and adult) and in meningiomas and malignant gliomas. In fetal brain five different forms could be detected by electrophoresis (K4, K3M, K2M2, KM3, and M4). In adult brain the M4-type, K3M hybrid, and K4-type are present; the M isozyme is largely predominant. Alanine inhibition of pyruvate kinase is in agreement with the electrophoretic pattern. Pyruvate kinase from fetal brain and brain of a newborn is more inhibited compared with pyruvate kinase from adult brain. The Lineweaver-Burk plots for pyruvate kinase from fetal brain and brain of the newborn are nonlinear due to the presence of hybrids. Pyruvate kinase from meningiomas and malignant gliomas is strongly inhibited by alanine. Electrophoresis proved the presence of mainly K4 type and the hybrid K3M, which is in agreement with the alanine inhibition. Determination of the Km's for phosphoenolpyruvate supports this conclusion. The determination of the alanine inhibition of pyruvate kinase may be a diagnostic tool in surgery for gliomas.

Alanine↗
PubMed1977

Alanine inhibition of pyruvate kinase in gliomas and meningiomas. A diagnostic tool in surgery for gliomas?

In gliomas a shift was found in the composition of enzymes, manifested by abnormal inhibition of pyruvate kinase by alanine. This study demonstrates the appearance of the MII-type isoenzyme in various gliomas. This MII type is also found in meningiomas but not in normal brain tissue. The method of enzyme examination described may be valuable as a diagnostic aid in the surgery of gliomas.

Alanine↗
PubMed1977

Results of surgical treatment of idiopathic developmental stenosis of the lumbar vertebral canal. A review of twenty-seven years' experience.

Between 1948 and 1975 147 patients were treated surgically for developmental stenosis of the lumbar vertebral canal, measurement of the mid-sagittal diameters in the whole area of stenosis being performed in 116 patients. Ninety-two of these patients were followed up for periods varying between one and twenty years. About two-thirds were completely relieved fo symptoms and signs. Sciatica and intermittent claudication were more frequently cured than radicular deficit and lumbago, the latter being the most frequent persisting symptom. A permanent neural deficit as a result of the surgical procedure was noted in two cases. A detailed presentation of the technique, complications and results is given.

Adult↗