Biomedical subjects

N Jeffery

Publications and source records attributed to N Jeffery.

4 recordsLinked to original sources

PubMed2005

Ethmoidal encephalocoele associated with seizures in a puppy.

A six-month-old puppy was presented for investigation of a seizure disorder. Neurological examination indicated persistent cerebral dysfunction in the absence of any identifiable metabolic disorder and magnetic resonance imaging revealed extension of the rostral lobes of the cerebrum into the nasal cavity. Despite symptomatic treatment, the puppy continued to exhibit seizures and appeared distressed and so was euthanased. Postmortem examination confirmed the abnormal anatomy of the rostral part of the brain and absence of a cribriform plate. There was extensive grey and white matter degeneration plus intraparenchymal haemorrhage in the abnormal brain tissue. The findings are consistent with a diagnosis of ethmoldal encephalocoele--a condition that has not previously been reported in the dog.

Animals↗

PubMed2002

A high-resolution MRI study of linear growth of the human fetal skull base.

The skull base, otherwise referred to as the basicranium or cranial base, plays a key role in the process of skull development, providing both support for the brain and an architectural component of the craniofacial complex. Consequently, the fetal skull base has been the focus of numerous studies employing various methods, including sectioning, plain radiography and CT. This paper investigates high-resolution (hr) MRI as an alternative method for looking at and quantifying the fetal skull base. The evaluation tests two basic hypotheses drawn from previous studies. These suggest that the anterior segment of the midline skull base grows more rapidly than the posterior segment and that the width of the posterior cranial fossa increases disproportionately in relation to its length. I imaged 42 formalin preserved human fetuses from museum collections with hrMRI. The T2-weighted image voxels were significantly smaller than those acquired with conventional clinical MRI. Landmarks of the fetal skull base were identified on reformatted axial and sagittal images. Bivariate plots revealed that the growth rate of the anterior skull base is almost twice that of the posterior skull base and that increases in the width of the posterior cranial fossa exceed those in its length. These findings confirm those of previous investigations and show that hrMRI offers a way forward in noninvasive quantification of fetal morphology.

Cranial Fossa, Posterior↗

PubMed2000

Using diagnostic radiology in human evolutionary studies.

This paper reviews the application of medical imaging and associated computer graphics techniques to the study of human evolutionary history, with an emphasis on basic concepts and on the advantages and limitations of each method. Following a short discussion of plain film radiography and pluridirectional tomography, the principles of computed tomography (CT) and magnetic resonance imaging (MRI) and their role in the investigation of extant and fossil morphology are considered in more detail. The second half of the paper deals with techniques of 3-dimensional visualisation based on CT and MRI and with quantitative analysis of digital images.

Animals↗

PubMed1996

Lead poisoning in telephone cable strippers: a new setting for an old problem.

Lead poisoning among workers processing lead sheathed telephone cable was identified at five worksites. High blood lead levels (BLLs) were identified during the medical evaluation of symptomatic workers following employer mandated air monitoring and through employer mandated blood lead levels. Once high BLLs were identified, governmental agencies became involved at every site, either as a result of worker complaints to OSHA or as a registry reporting mechanism. Workplace evaluation revealed significant overexposure to lead, particularly among workers mechanically stripping the lead sheaths. After intervention by a government agency, four of the workplaces chose to stop lead cable processing. Because the ongoing replacement of lead sheathed telephone cable with fiber optics may be continuing in many areas of the country, there is concern that the clusters we have identified represents a widespread and little recognized setting for lead overexposure. Recommendations for preventing overexposure to lead in this setting are given.

Conservation of Natural Resources↗