PubMed Health⌕ Search

Biomedical subjects

J Meaney

Publications and source records attributed to J Meaney.

8 recordsLinked to original sources

Tracheoesophageal compression associated with substernal goitre. Correlation of symptoms with cross-sectional imaging findings.

OBJECTIVE: The aim of this study was to compare the subjective tracheoesophageal pressure symptoms associated with substernal goitres with objective cross-sectional radiographic measurements. DESIGN: Patients with substernal goitre were questioned regarding tracheoesophageal compression symptoms and these data were analysed for correlation with radiographic and intra-operative findings. RESULTS: Twenty-six patients were included. Patients with airway symptoms including dyspnoea, stridor and coughing were more likely to have significant tracheal narrowing on pre-operative computed tomography (CT) imaging. There was also a significant correlation between the perceived severity of lump sensation in the throat and the presence of tracheal and oesophageal displacement and retrotracheal extension of the thyroid mass. CONCLUSION: Pre-operative CT measurements of tracheal and oesophageal displacement, retrotracheal extension and the degree of tracheal compression correlate well with the presence and severity of tracheoesophageal pressure symptoms. None of the radiographic findings that are exclusive to substernal goitre (percentage of substernal mass, goitre size at the level of the thoracic inlet, ratio of goitre size to the vertebral body at the thoracic inlet and retrosternal isthmus size) had any correlation with clinical symptoms in this study.

Airway Obstruction↗

MRI in the investigation of Morton's neuroma: which sequences?

Morton's 'neuroma' is a painful focus of peri-neural fibrosis, which may affect the interdigital nerves of the feet. Clinical diagnosis and localization may be inaccurate. Computed tomography (CT), ultrasound and magnetic resonance imaging (MRI) have been used to confirm the diagnosis pre-operatively. Recently, MRI using T1-weighted sequences with fat saturation after i.v. Gadolinium DTPA has been suggested as the most effective MR sequence for depiction of Morton's neuroma of the neuroma of the forefoot. Our results show that T1-weighted axial and coronal images with an axial FSE T2-weighted sequence detect neuromata more consistently than an enhanced T1 fat suppressed sequence.

Contrast Media↗

Dietary regulation of the renal sodium-phosphate (Na+/Pi) transporter during early ontogeny in the rat.

Phosphates are necessary for proper skeletal growth and function, as well as for growth and development of cells. Phosphate repletion depends partly on the function of the renal sodium-phosphate (Na+/Pi) transport system that functions to recover filtered urinary phosphate. It has been suggested that in order to meet the higher phosphate requirement of the developing animal, the weanling rat would have a greater adaptive response to chronic phosphate deprivation than the adolescent rat. The current study sought to characterize the adaptive response to dietary phosphate deprivation in terms of Na+/Pi transporter activity, and mRNA and immunoreactive protein levels. Weanling and adolescent rats were pair fed either a low-phosphate diet (LPD) or a control-phosphate diet (CPD) for 1 week. Maximal rates of transport (Vmax) were not different in weanling or adolescent rats on CPD (weanling 2.13 +/- 0.29 nmol/mg protein/10 sec, and adolescent 1.41 +/- 0.036 nmol/mg protein/10 sec, n = 3). K(m) values were not different in either group on CPD (weanling 0.15 +/- 0.08 mM Pi, and adolescent 0.22 +/- 0.13 mM Pi). There were no difference in mRNA abundance (Na+/Pi transporter/1B15 = 0.194 +/- 0.12 for weanling and 0.230 +/- 0.03 for adolescents, n = 3) or immunoreactive protein levels (Na+/Pi transporter/beta-actin = 0.232 +/- 0.01 for weanlings and 0.300 +/- 0.05 for adolescents, n = 3) in the two groups when fed CPD. After chronic Pi deprivation, the weanling rat showed a greater adaptive response than the adolescent as measured by Vmax values (weanling LPD/CPD = 2.01, P < 0.01; adolescent LPD/CPD not different; n = 3), mRNA signal intensity (weanling LPD/CPD = 1.86, P < 0.05; adolescent LPD/CPD not different; n = 3), and protein signal intensity (weanling LPD/CPD = 3.63, P < 0.01, and adolescent LPD/CPD 1.91, P < 0.05; n = 3). K(m) values were not affected by LPD. Immunohistochemical analysis of kidney cortex showed greater apical staining in both groups on LPD, with the increase being noticeably greater in the weanlings. Furthermore, two-way analysis of variance demonstrates a significant adaptive response in the weanling period in regard to maximum transport capacity (Vmax) and immunoreactive protein (Western), suggesting a synergistic effect between the developmental stage and low-phosphate diet. Therefore, it appears that the adaptive response is greater in the more rapidly developing animal (the weanling), and these results suggest a compensatory mechanism to conserve phosphate during periods of rapid growth.

Animals↗

Epigenetic factors controlling the development of avian Purkinje neurons.

Using a unique protocol, we have developed an avian neuron culture system in which a high yield of Purkinje neurons is obtained more readily than with pre-existing methods. Purkinje neurons were identified in vitro using the specific antibodies calbindin and cyclic GMP-kinase. Survival of Purkinje neurons was dependent on astrocyte contact and enhanced by astrocytic factors supplied to the medium by a monolayer of astrocytes grown on coated membranes suspended in the culture wells but not in contact with the neurons. The age of the cerebellum from which astrocytes were obtained was shown to affect the morphological development of the Purkinje neurons suggesting the developmentally-regulated expression of growth factors. However, in the presence of the astrocytes, Purkinje neurons could only progress to a limited stage of development based on morphological criteria. The addition to the culture of cerebellar granule neurons at a time of Purkinje neuron development that they would expect to encounter them in vivo resulted in a shift of Purkinje neurons to a mature phenotype. This maturation effect was increased in response to increasing levels of granule neurons, but was independent of the granule neuron ages used. This system offers significant advantages over other Purkinje neuron culture systems and will be useful for studying the extrinsic factors involved in Purkinje neuron development and histogenesis.

Animals↗

Intraosseous lipomas.

Intraosseous lipomas are considered to be rare tumours. We describe four cases and discuss their appearances and diagnosis. It is likely with the increasing frequency of computed tomography and magnetic resonance examinations of the lumbar spine that many more asymptomatic lesions will present to the radiologist and that these tumours are not as rare as the literature would suggest.

Adult↗

Cannonball metastases with favourable prognosis.

BACKGROUND: Secondary 'cannonball' metastases to the lung are frequent and usually associated with disseminated malignancy and poor prognosis. AIM: To report the case of a patient with metastatic pulmonary endometrial stromal sarcoma who had a previous hysterectomy for benign uterine fibroids and no past history of malignancy. RESULT: A 70-year-old female presented with cannonball metastases in her lung. Four years previously she had a hysterectomy for 'fibroids'. Review of the original histology revealed endometrial stromal sarcoma, similar to the lung metastasis. She currently has a good prognosis. CONCLUSION: A patient with 'cannonball' metastases can have a favourable prognosis. A female patient with a previous hysterectomy for uterine fibroids, should be considered to have metastatic sarcoma until proven otherwise.

Aged↗