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Biomedical subjects

A D Murray

Publications and source records attributed to A D Murray.

At least 19 recordsLinked to original sources
PubMed2000

Respiratory difficulty following bismuth subgallate aspiration.

Bismuth subgallate, an agent that initiates clotting via activation of factor XII, has been advocated for use in controlling bleeding during tonsillectomy and adenoidectomy. Direct aspiration of bismuth has produced pulmonary complications in laboratory animals, but no clinical correlation in humans has been previously described. We report 2 cases of bismuth aspiration that resulted in respiratory difficulty after tonsillectomy and adenoidectomy. Neither child's respiratory compromise required airway intubation. This report of pulmonary complications secondary to bismuth aspiration should alert surgeons to the potential for airway problems when using bismuth as a hemostatic agent for tonsillectomy and adenoidectomy.

Adenoidectomy↗
PubMed2000

Competence in language at 24 months: relations with attachment security and home stimulation.

This study explored the interrelations among attachment, home stimulation, and language development in 58 toddlers (36 medically high risk and 22 low risk) at 24 months of age. The results indicated that there were additive effects of attachment and home stimulation on language competence, especially on receptive abilities. Mothers who had established secure relationships and provided stimulating home environments had children with the highest language scores.

Child Development↗
PubMed2000

Changes in the rCBF images of patients with Alzheimer's disease receiving Donepezil therapy.

Alzheimer's disease is associated with a loss in presynaptic cholinergic function. It has been suggested that cholinergic inhibitors such as donepezil hydrochloride (Donepezil) could restore this function and improve some of the symptoms of Alzheimer's disease. Previous work has shown that Donepezil improves cognitive and global function in patients with mild to moderate Alzheimer's disease. This study reviewed retrospectively 12 patients who had previously had a 99Tcm-hexamethylpropylene amine oxime (99Tcm-HMPAO) single photon emission tomography (SPET) regional cerebral blood flow (rCBF) examination and had gone on to receive Donepezil therapy. These patients were recalled for a further 99Tcm-HMPAO SPET rCBF examination and the image data sets were compared. The results showed an overall increase in global cerebral blood flow (P = 0.04) averaged over the group with a percentage change in blood flow ranging from -1.8% to 6.4%. However, some patients showed a slight decrease in blood flow. When the data were analysed in terms of regional cerebral blood flow, we found that the most significant increase in blood flow occurred in the frontal lobes (P = 0.02).

Aged↗
PubMed2000

Nuclear medicine in oncology.

The role of the nuclear medicine department in the diagnosis and management of malignant disease is constantly evolving. For example, the development of new radiopharmaceuticals, such as indium-111-labelled octreotide (pentetreotide), has enabled more specific imaging for the diagnosis of gastroentero-pancreatic (GEP) endocrine tumours to be carried out. New techniques such as sentinel lymph node localisation and biopsy now allow less invasive tumour staging. Advances in chemotherapy necessitate careful monitoring of the effects of chemotherapeutic drugs on normal organ function during follow-up, and tumour specific radiopharmaceuticals are being used for non-invasive, targeted tumour therapy. Nuclear medicine investigations should always be interpreted in the knowledge of results of other imaging investigations if they are to have greatest impact on patient care.

Humans↗
PubMed2000

HMPAO SPECT imaging of Alzheimer's disease patients with similar content-specific autobiographic delusion: comparison using statistical parametric mapping.

UNLABELLED: Delusional behavior and thinking are common symptoms in Alzheimer's disease (AD). In the past, these delusions have been considered to be psychotic complications of global neurologic dysfunction. Recently, authors have suggested that content-specific delusions in AD are associated with discrete regional abnormalities of the right hemisphere. METHOD: This study compared 99mTc-hexamethyl propyleneamine oxime (HMPAO) SPECT images of a group of AD patients with a similar autobiographic delusion with a group of AD patients without delusions and a group of AD patients with a range of delusions but without autobiographic content. The reconstructed SPECT data were compared using a statistical parametric mapping technique. RESULTS: The autobiographic AD group had a significant area of hypoperfusion in the right frontal lobe when compared with the 2 other groups. The area of hypoperfusion included parts of Brodmann's areas 9 and 10. Region 9 has been identified previously as having a role in episodic memory retrieval. CONCLUSION: This result suggests that autobiographic delusions in AD may have an identifiable neuropsychologic mechanism and that it may be possible to identify an organic cause in some patients using 99mTc-HMPAO SPECT.

Aged↗
PubMed1999

Accuracy of T1 measurement in dynamic contrast-enhanced breast MRI using two- and three-dimensional variable flip angle fast low-angle shot.

In vivo T1 measurements, used to monitor the uptake of contrast agent by tissues, are typically performed as a first step in implementing compartmental analysis of contrast-enhanced breast magnetic resonance imaging (MRI) data. We have extended previously described methodology for in vivo T1 measurement (using a variable flip-angle gradient-recalled echo technique) to two-dimensional (2D), fast low-angle shot (FLASH). This approach requires computational modeling of slice-selective radiofrequency (RF) excitation to correct for nonrectangular slice profiles. The accuracy with which breast tissue T1 values can be measured by this approach is examined: T1 measurements from phantom and in vivo image data acquired with 2D and 3D FLASH imaging sequences are presented. Significant sources of error due to imaging pulse sequence quality and RF transmit field nonuniformity in the breast coil device that will have detrimental consequences for compartmental analysis are identified. Rigorous quality assurance programs with calibrated phantoms are thus recommended, to verify the accuracy with which T1 measurements are obtained.

Breast↗
PubMed1999

Metformin and contrast media--a dangerous combination?

Metformin is a biguanide used to treat type II diabetes mellitus. Since the recent introduction of this drug into the United States there has been considerable interest in metformin associated lactic acidosis (MALA) following intravenous contrast media. The Royal College of Radiologists published advice in November, 1996 (Advice to Members and Fellows with regard to metformin-induced lactic acidosis and X-ray contrast medium agents, RCR Publication) supporting the manufacturers' advice that metformin should not be used in the 48 h before or after intravenous (i.v.) contrast medium. We performed a systematic review of the literature and this has shown that almost all reported cases of MALA following i.v. contrast medium occurred where there was either pre-existing poor renal function or another contraindication to metformin usage. There has been only one reported case of lactic acidosis following the use of intravenous contrast medium in a patient with normal renal function. We suggest that the Royal College of Radiologists' advice should be modified and that it is safe to give i.v. contrast medium to patients on metformin with normal renal function.

Acidosis, Lactic↗
PubMed1998

Slipped and lost muscles and other tales of the unexpected. Philip Knapp Lecture.

Loss of a rectus muscle may occur as a rare complication of strabismus surgery. In addition, extraocular muscles may become traumatically detached from the globe when they rupture or are transected as the result of an injury or during the course of retinal detachment or paranasal sinus or orbital surgery. Although the clinical features of a slipped muscle may resemble those of a lost muscle, the findings at the time of reoperation are distinct. Also the etiology, and therefore the prevention, of a slipped muscle differs from that of a lost muscle. It is likely that slipped muscles and even some lost muscles are underdiagnosed and represent a significant cause of unexpected overcorrection or undercorrection. Unless the displaced muscle is appropriately advanced, it can be extremely difficult to correct the associated strabismus, yet locating and repairing either a lost or slipped muscle can be challenging and is by no means always successful. Current concepts pertaining to the etiology, recognition, and management of slipped and lost muscles will be discussed.

Adolescent↗
PubMed1998

Untreated essential infantile esotropia: factors affecting the development of amblyopia.

PURPOSE: A concomitant esotropia, presenting within the first 6 months of life, associated with a high incidence of dissociated vertical deviation, manifest latent nystagmus and asymmetric optokinetic nystagmus is termed essential infantile esotropia. Most studies concern patients diagnosed in infancy and treated throughout childhood. This paper addresses the factors that may influence the development of amblyopia in patients who remain untreated until visual adulthood. METHODS: During a 3 year period 113 patients aged 8 years or more with a history of esotropia occurring within the first 6 months of life were examined for the study. All patients underwent full ocular motility assessment and cycloplegic refraction, and only those with one or more signs of essential infantile esotropia were included. RESULTS: Of the 113 patients, 16 (14.3%) had a difference of 2 or more lines in the visual acuity of the two eyes and were diagnosed as having amblyopia. Anisometropia was present in 10 of the 16 (62.5%). The correlation between anisometropia and amblyopia was statistically significant (p = 0.0001). CONCLUSIONS: Amblyopia following early surgical intervention in essential infantile exotropia is well documented, but the risk is outweighed by the chance of obtaining some form of binocular vision. However, where access to ongoing therapy is not available, patients with essential infantile esotropia, free alternation and no anisometropia have a significant chance of retaining good visual acuity in both eyes if surgery is delayed until visual adulthood.

Adolescent↗
PubMed1997

Maternal directive and facilitative interaction styles: associations with language and cognitive development of low risk and high risk toddlers.

The purpose of this study was to examine the relation of maternal interaction styles to the development of a sample of 56 toddlers (19 low risk, 37 high risk) seen at 12 and 24 months of age. At 12 months, videotapes of mother-child interaction were coded for directiveness, sensitivity, and elaborativeness. At 12 and 24 months, cognitive and language measures were collected. A directive maternal style was negatively correlated with sensitivity and elaborativeness, whereas sensitive and elaborative ratings were positively correlated, suggesting a facilitative style. Regression models significantly predicted receptive language and cognitive development at 24 months but not expressive language. Maternal directiveness at 12 months was negatively relative to later receptive language skills, whereas elaborativeness at 12 months was positively predictive of later cognitive development. Child status variables and maternal interactional styles contributed about equally to the prediction of later cognitive and language outcomes.

Child Language↗
PubMed1996

Choice of contrast enhancement index for dynamic magnetic resonance mammography.

Indices are often used in dynamic MRI of the breast to quantitate signal enhancement within suspicious lesions. Two indices are commonly used: one calculates the difference in pre- and postcontrast signal intensity, normalised to a base-line signal intensity such as that of fat (which does not enhance) whilst the other calculates the ratio of pre- to postcontrast signal intensity. The results of a computational simulation are presented which demonstrate the superiority of the normalised signal difference index, based on the criterion that the best index is that which is least influenced by initial tissue T1. This hypothesis was tested by comparing the two indices in a group of patients with clinical or mammographic suspicion of recurrent breast carcinoma. Of 37 patient examinations using Gadolinium enhanced MRI of the breast, 11 patients showed 13 lesions with some degree of enhancement, which were subsequently diagnosed histologically as either benign or malignant. The normalised signal difference index showed no overlap between the benign and malignant groups, whereas some overlap was observed with the signal ratio index. The clinical findings are therefore consistent with the results of the computational simulation.

Adult↗
PubMed1996

Clinically suspected scaphoid fracture: a comparison of magnetic resonance imaging and bone scintigraphy.

59 patients with clinical suspicion of scaphoid fracture, but negative radiographs at presentation and review, were examined by magnetic resonance imaging (MRI) and bone scintigraphy (BS). The diagnoses were compared with subsequent follow-up. There were four scaphoid fractures, 10 other fractures and three significant ligamentous injuries. All scaphoid fractures were identified by MRI and BS. MRI showed better interobserver agreement for scaphoid injury than BS and fewer false positive reports. Significant ligamentous injury and carpal instability diagnosed by MRI were not evident on scintigraphy. Using fast scanning protocols, the cost of MRI is comparable with that of BS. MRI should be considered as the appropriate second line investigation in these clinical circumstances.

Adolescent↗
PubMed1996

Measurement of spin-lattice relaxation times with FLASH for dynamic MRI of the breast.

Using a variable flip angle gradient refocused imaging technique, dynamic quantitative T1 relaxation maps acquired before and after the administration of a gadolinium contrast bolus enable the concentration-time curve of the paramagnetic agent in breast tissue to be calculated. This imaging technique has the aim of improving the diagnostic accuracy of MR mammography. Measurements with phantoms of calibrated T1 values have been carried out to investigate the accuracy of the method, with particular reference to errors caused by incomplete spoiling of residual transverse magnetization and inaccurate radio frequency (RF) flip-angle settings. A clinical example is presented. The method has potential use for any patient study which necessitates rapid quantitation of changing in vivo T1 values as a result of contrast agent injection.

Breast Neoplasms↗
PubMed1996

Dynamic magnetic resonance mammography of both breasts following local excision and radiotherapy for breast carcinoma.

The purpose of this study was to evaluate a dynamic gadolinium-diethylene-triaminepentacetate (Gd-DTPA) enhanced magnetic resonance mammography (MRM) protocol, incorporating image subtraction and using a dedicated double breast coil, in patients with treated breast cancer. 36 patients who had undergone breast conserving surgery and radiotherapy, with clinical or mammographic suspicion of locally recurrent breast carcinoma, were examined. 3D rapid volume imaging of both breasts was performed before and repeated three times, at 1, 2 and 3 min, following Gd-DTPA enhancement. Image subtraction allowed identification of enhancing lesions and quantitative analysis of these was performed. Five patients had six lesions demonstrating rapid enhancement in the first minute, all of which were histologically confirmed recurrent or second primary tumours. Slower enhancement was seen in six benign lesions and diffuse enhancement was seen in one patient within 6 months of treatment. The dynamic protocol used allowed sufficient temporal resolution for distinguishing malignant from benign lesions at the site of previous surgery and ensured that both breasts were imaged in their entirety, thus enabling the diagnosis of multifocal and second primary tumours.

Adult↗
PubMed1995

The effect of reducing the exposure time of mitomycin C in glaucoma filtering surgery.

BACKGROUND: The use of adjunctive intraoperative mitomycin C has considerably improved the success rate of glaucoma filtering surgery. However, the ideal concentration and exposure time of mitomycin C is unknown. The purpose of this study is to determine whether a satisfactory surgical outcome can be achieved with a lower incidence of adverse side effects by using a shorter exposure time of mitomycin C than has been recommended previously. METHODS: Twenty-five eyes of 25 consecutive patients who were considered to be at high risk for surgical failure because of their age (< 55 years), previous failure of trabeculectomy, previous cataract surgery, or traumatic glaucoma received a single intraoperative application of mitomycin C (0.2 mg/ml for 2 minutes). They were case-matched with a group of 48 consecutive patients who received a single intraoperative application of mitomycin C (0.2 mg/ml for 5 minutes) by using age, race, type of refractory glaucoma, and preoperative intraocular pressure (IOP) as variables. RESULTS: Eighteen months after surgery, 22 (88%) patients in the 2-minute group and 21 (84%) patients in the 5-minute group had an IOP less than 21 mmHg with or without treatment. No significant differences were found in the complication rate: in 2 (8%) of 25 eyes of the 2-minute group, chronic hypotony developed compared with 3 (12%) of 25 eyes in the 5-minute group. Hypotony-related maculopathy developed in one eye in the 5-minute group. A cystic bleb was found in 15 (60%) eyes in the 2-minute group compared with 19 (76%) eyes in the 5-minute group, although this difference was not statistically significant. Two (8%) eyes in the 2-minute group and one eye (4%) in the 5-minute group had a bleb-related infection. In one (4%) patient in each group, late severe endophthalmitis developed. CONCLUSION: These results suggest that a 2-minute intraoperative application of 0.2 mg/ml mitomycin C is as effective as a 5-minute exposure, but the complication rate remains unaltered.

Adult↗
PubMed1993

Trabeculectomy with mitomycin C for refractory glaucoma in blacks.

The use of one intraoperative application of mitomycin C at the filtration site has been effective in eyes at increased risk for failure of routine trabeculectomy. To study the efficacy and safety of this technique in patients with refractory glaucoma, we prospectively examined 30 eyes of 26 black patients in whom a 0.2-mg/ml solution of mitomycin C was applied between Tenon's capsule and the sclera for five minutes before trabeculectomy. The results were compared to those found in a matched group of 30 eyes of 28 patients who underwent trabeculectomy without mitomycin C. The mean postoperative intraocular pressures were significantly lower in the mitomycin C group than in the control group (P = .001). Of the 30 eyes in the mitomycin C group, 25 (83%) had an intraocular pressure of less than 21 mm Hg without glaucoma medication, compared to 11 of 30 (37%) in the control group (P = .00006). In the mitomycin C group, 19 eyes (63%) developed a cystic avascular thin-walled filtering bleb, four eyes (13%) a late positive Seidel test, and one eye slight scleral thinning over the area where the mitomycin C was applied. Although mitomycin C is effective when used in this manner, further study is required to determine the long-term complications.

Adult↗