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Biomedical subjects

J J Kerrigan

Publications and source records attributed to J J Kerrigan.

5 recordsLinked to original sources

Matrix turnover.

This review concentrates on how the major component of extracellular matrix, collagen, is catabolized. This process is important in a number of aspects of orthodontics since matrix is constantly turning over, the rate of which differs in embryogenesis, ageing, disease, and physiological processes, such as orthodontic tooth movement. It is not the purpose of this review to consider each process in detail. The aim is to give a clear account of the matrix metalloproteinases (a major family of proteinases) including their classification, properties, and functions.

Collagen↗

Palatogenesis and potential mechanisms for clefting.

This review concentrates on mechanisms of palatogenesis. This includes theories of shelf elevation, the role of matrix and identification of molecules and growth factors, which have key roles. The areas where failure to develop could potentially lead to clefting are highlighted. A key part of shelf fusion is the breakdown of the medial edge epithelium, a process that is probably dependent on enzymes involved in matrix turnover. There is good evidence that the matrix metalloproteinases may provide a common link to the multiple genetic and environmental factors that are known to cause clefting.

Cleft Palate↗

The role of cell adhesion molecules in craniofacial development.

The last decade has seen classification and characterization of previously identified glycoproteins which have been associated with cell adhesion. More recently, it has been realized that the range of these molecules is even wider than originally thought. Cell adhesion molecules are important in early development and their role in craniofacial development is now apparent. Furthermore, the interaction of cell adhesion molecules in other developmental phenomena such as epithelial mesenchymal transformation (EMT), reinforces the suggestion that these molecules are important in the later stages of development, particularly organogenesis. This article reviews the role of cell adhesion molecules in embryogenesis, with a particular emphasis on foetal craniofacial development.

Cell Adhesion Molecules↗

Motor evoked potentials and central motor conduction: studies of transcranial magnetic stimulation with recording from the leg.

To determine central conduction times in the corticospinal pathways of humans using magnetic stimulation, we have developed a method for consistently recording conduction times between the motor cortex and the L4-5 level of the spinal cord. In 30 subjects, motor evoked potentials (MEPs) were recorded from the tibialis anterior muscle following contralateral motor cortex and peroneal nerve stimulation. In 18 of these subjects, the L4-5 intervertebral space was stimulated. The stimuli consisted of single, painless, short-duration magnetic pulses. In 12 subjects, measurements were made during voluntary ankle dorsiflexion, and during vibration of the TA tendon at rest. All subjects had measureable MEP latencies of 30.3 +/- 2.2 msec (mean +/- S.D.). The central motor conduction time (CMCT) was calculated using both a direct as well as an indirect method. The direct method in 18 subjects had a mean value of 16.2 +/- 1.7 msec, while the indirect method in all 30 subjects was 13.8 +/- 1.8 msec. No significant correlation of the CMCT was found with either age or height in these subjects. Ankle dorsiflexion significantly reduced the MEP latency and increased the amplitude, whereas vibration of the TA tendon significantly increased the amplitude alone. We conclude that MEPs may be consistently and painlessly measured in the lower extremity using magnetic stimulation in adults. Facilitation of the MEPs was produced more consistently by voluntary contraction than by vibratory stimulation of the tibialis anterior muscle tendon. Finally, CMCT was independent of both age and height in our study population.

Adult↗

Ganglion cysts and carpal tunnel syndrome.

We review 12 cases of ganglion cyst with carpal tunnel syndrome in 11 patients seen at the Hand Rehabilitation Center. Mean age was 42 years (range, 28 to 60 years). One half of the cysts were associated with direct trauma, usually with wrist hyperextension. Symptoms usually developed after the appearance or sudden growth of the cyst. Motor conduction or distal sensory latency was abnormal in seven of eight studied cases. Tinel's sign on tapping the cyst may be pathognomonic for this syndrome. Cyst removal and incision of the flexor retinaculum relieved the symptoms in 11 cases. The other case had total resolution after spontaneous cyst rupture. This syndrome is successfully treated with cyst decompression with release of the carpal canal and has an excellent prognosis. To our knowledge this represents the largest operative series of carpal tunnel syndrome and ganglion cyst.

Adult↗