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Biomedical subjects

J V Hunter

Publications and source records attributed to J V Hunter.

At least 37 records · Page 2Linked to original sources
PubMed1998

Advances in pediatric neuroimaging.

Magnetic resonance evaluation of the pediatric central nervous system is rapidly improving in a number of ways: (1) anatomically with higher resolution; (2) with greater sensitivity to pathological processes characterized by increased water content utilizing fluid attenuated inversion recovery imaging (FLAIR); (3) with greater speed of acquisition with ultrafast (1 s/image) and echo planar imaging techniques (50 ms/image); (4) with measurement of cerebral blood flow as perfusion; (5) with measurement of water proton dispersion (e.g. diffusion imaging); (6) with measurement of biochemical components within tissues with proton spectroscopy; and (7) with evaluation of cortical activation with functional magnetic resonance imaging.

Central Nervous System Diseases↗
PubMed1998

Hemifacial microsomia in a newborn with hypoplastic skin lesions, an eyelid skin tag, and microphthalmia: an unusual presentation of Delleman syndrome.

Delleman syndrome (oculocerebrocutaneous syndrome) is characterized by orbital cysts, periorbital skin appendages, and focal cutaneous hypoplasia. We describe a male infant with findings associated with this condition, including an eyelid appendage, discrete hypoplastic skin lesions, unilateral microphthalmia, and hydrocephalus. In addition, he had striking unilateral mandibular hypoplasia and microtia, features often present in the oculoauriculovertebral (OAV) spectrum. However, hypoplastic skin lesions and eyelid appendages are not features of the OAV spectrum. The marked degree of hemifacial microsomia present in this child has not been previously noted in Delleman syndrome. Two patients with Delleman syndrome have been previously described who have features typically present in the OAV spectrum. This case demonstrates that characteristics of both Delleman syndrome and the OAV spectrum may be present in one individual.

Abnormalities, Multiple↗
PubMed1998

Rasmussen encephalitis: complementary role of multitechnique neuroimaging.

Rasmussen encephalitis is a chronic, progressive inflammation of the brain of unknown origin. Early diagnosis and treatment with immunoactive agents and/or hemispherectomy are sought to prevent the progressive cognitive decline that accompanies this disease. Combined anatomic and functional neuroimaging may serve to focus the diagnostic workup and to hasten brain biopsy for definitive diagnosis. Two biopsy proved cases of Rasmussen encephalitis are presented. The importance of MR imaging, single-photon emission computed tomography, and proton MR spectroscopy in the workup of this disease is discussed.

Child↗
PubMed1997

Progressive multifocal leukoencephalopathy in an HIV-infected child.

A child with perinatally acquired HIV infection presented with acute neurologic deterioration. A cerebellar white matter lesion seen on CT and MRI later proved to be progressive multifocal leukoencephalopathy (PML) by histology. Although a recognized disease of HIV-infected adults, PML is certain to be seen with more frequency in HIV-infected children who are surviving longer as a result of improved medical care. Recognition of the clinical and radiographic manifestations is important because of the dismal prognosis.

AIDS Dementia Complex↗
PubMed1996

Functional neuroimaging: radiology.

Rapid advances, in respect of the visual and auditory systems, have occurred in neuroimaging over the past year in the area of so-called 'functional imaging', and in particular of functional magnetic resonance imaging. This has been accelerated by the introduction of echo-planar imaging, which allows for the very fast acquisition (< 100 ms/image) of multislice images. Radiology is no longer just a question of interpreting anatomy, for, with the ability to combine structure with function, we are now able to extract physiological information. This opens up exciting possibilities for advances in the field of neuroscience, and functional imaging will therefore form the main thrust of this review.

Auditory Cortex↗
PubMed1996

Tethered cord and associated vertebral anomalies in children and infants with imperforate anus: evaluation with MR imaging and plain radiography.

PURPOSE: To evaluate in children and infants with imperforate anus the prevalence and types of occult myelodysplasia that may result in tethered cord and the association of these lesions with vertebral anomalies. MATERIALS AND METHODS: Records and images were retrospectively reviewed in 86 patients who underwent spine magnetic resonance imaging and had either low-level imperforate anus (n = 30), intermediate-level imperforate anus (n = 15), or high-level imperforate anus (n = 41). RESULTS: Thirty-one of 86 patients (36%) had occult myelodysplasia suggestive of tethered cord (27% of all patients with low-, 33% of all patients with intermediate-, and 44% of all patients with high-level lesions). Of these 31 patients, 16(52%) were asymptomatic, 24, (77%) had a thickened fatty filum, 13 (42%) had normal conus position, and 23 (74%) had vertebral anomalies. Twenty-four of the 31 patients (77%) underwent surgical untethering. CONCLUSION: A substantial number of patients with all types of imperforate anus have occult myelodysplasia that may necessitate surgical intervention, including those patients with normal spine radiographs.

Abnormalities, Multiple↗
PubMed1995

Critical review of microfixation in pediatric craniofacial surgery.

The migration or passive intracranial translocation of microplates and screws in the pediatric craniofacial patient has been reported. A retrospective review was undertaken to clarify the incidence of microplate translocation and identify potential clinical implications. Computed tomographic imaging demonstrated internalization of microfixation in 14 of 27 pediatric patients. Statistically significant factors for microplate translocation include longer plates (p < 0.05) and those placed in the temporal region (p < 0.001). Younger patients and those with syndromic craniofacial dysostosis also had a higher incidence of translocation. Specific complications relating to the translocation of microplates were not found in any patient. The direct effects of translocated microplates and screws on the underlying brain and dura remain unclear.

Bone Plates↗
PubMed1993

Magnetic resonance spectroscopy shows increased brain glutamine in ornithine carbamoyl transferase deficiency.

We have performed localized in vivo proton magnetic resonance spectroscopy on two females with ornithine carbamoyl transferase deficiency during episodes of acute hyperammonemic encephalopathy with focal neurologic abnormalities. Spectra obtained from 2 x 2 x 2 cm cubic volumes at relatively long (135-ms) echo times contain additional signals that are characteristic of glutamine and indicate that glutamine is present in very high concentrations in the brain. The findings are consistent with the hypothesis that intracerebral accumulation of glutamine contributes to the encephalopathy associated with hyperammonemia. In one of the children, spectra obtained after treatment showed a marked decrease in the glutamine signals.

Amino Acid Metabolism, Inborn Errors↗
PubMed1992

MRI demonstration of midbrain deformity in association with Chiari malformation.

The differentiation of Chiari malformation from intrinsic brainstem neoplasm in adults can be difficult. We report three patients presenting with brainstem signs, in whom midbrain abnormality was detected on computed tomography and interpreted as evidence of intrinsic tumour. Subsequent investigation by magnetic resonance imaging revealed evidence of Chiari I malformation in all three cases and a syrinx in two. The association of Chiari I with deformity of the midbrain or pons has not been described previously.

Aged↗
PubMed1992

Nonionic iodinated contrast media: potential renal damage assessed with enzymuria.

The potential of digital subtraction angiography (DSA) to enable study of the physiology of renal transplantation after a single intravenous injection of nonionic iodinated contrast material stimulated this investigation into the possible nephrotoxicity of the contrast material used. Levels of urinary enzyme activity, used as markers of renal damage, were measured before, immediately after, and up to 72 hours after intravenous injection of nonionic iodinated contrast material in two groups of patients undergoing DSA. Twenty-six patients had undergone renal transplantation and 10 control patients had normal renal function. Both groups showed a transient rise in the level of urinary enzyme activity that peaked within 24 hours and returned to levels obtained before DSA within 72 hours. In the transplantation group, the baseline levels of enzymes were higher, and the response after administration of contrast material was greater. Nevertheless, the duration of the response was the same as in the control group, and the enzyme levels of all patients returned to their pre-DSA baseline levels.

Acetylglucosaminidase↗
PubMed1992

Does myodil introduced for ventriculography lead to symptomatic lumbar arachnoiditis?

Although there is a substantial body of evidence implicating Myodil or Pantopaque as a cause of lumbar arachnoiditis, assessment of the clinically based evidence is complicated by the additional potentially causative factors present in a high proportion of cases. These include pre-existing spinal pathology, traumatic lumbar puncture and surgery. The aim of this retrospective study was to attempt to ascertain whether Myodil introduced via ventricular catheter was associated with subsequent development of symptomatic lumbar arachnoiditis. In 222 patients in whom clinical records were reviewed there was no excess of back pain following ventriculography compared to the general population. Myodil ventriculography does not appear to be a major cause of symptomatic lumbar arachnoiditis. Several unavoidable problems with the methodology of this study are discussed.

Adolescent↗
PubMed1990

Aneurysmal bone cyst of the sphenoid with orbital involvement.

We present a case of aneurysmal bone cyst involving the roof of the orbit and sphenoid bone, with plain film, computed tomography, and magnetic resonance imaging findings. The natural history and treatment depend on the presence of associated abnormalities such as fibrous dysplasia or a giant cell tumour. In this case the lesion was solitary and was successfully removed, so that possible complications from radiotherapy were avoided.

Bone Cysts↗
PubMed1989

Smoking and occupational allergy in workers in a platinum refinery.

OBJECTIVE: To test the hypothesis that smoking increases the risk of sensitisation by occupational allergens. DESIGN: Historical prospective cohort study. SETTING: Platinum refinery. SUBJECTS: 91 Workers (86 men) who started work between 1 January 1973 and 31 December 1974 and whose smoking habit and atopic state (on skin prick testing with common allergens) had been noted at joining. MAIN OUTCOME MEASURES: Results of skin prick tests with platinum salts carried out routinely every three to six months and records of any respiratory symptoms noted by the refinery's occupational health service. Follow up was until 1980 or until leaving refinery work, whichever was earlier. RESULTS: 57 Workers smoked and 29 were atopic; 22 developed a positive result on skin testing with platinum salts and 49 developed symptoms, including all 22 whose skin test result was positive. Smoking was the only significant predictor of a positive result on skin testing with platinum salts and its effect was greater than that of atopy; the estimated relative risks (95% confidence interval) when both were included in the regression model were: smokers versus non-smokers 5.05 (1.68 to 15.2) and atopic versus non-atopic 2.29 (0.88 to 5.99). Number of cigarettes smoked per day was the only significant predictor of respiratory symptoms. CONCLUSION: Smokers are at increased risk of sensitisation by platinum salts.

Adolescent↗
PubMed1987

Patterns of axillary lymphadenopathy demonstrated by mammography: implications for the asymptomatic woman in a breast screening programme.

Carcinoma of the breast is the commonest cause of mortality due to malignancy in women in England and Wales. Mammographic screening, with or without clinical examination, is being used increasingly to detect lesions at an earlier stage. In order to test the claim that an asymptomatic woman with axillary lymph nodes on mammography and no demonstrable underlying carcinoma has a greater than two-fold increased risk of developing subsequent breast cancer, a retrospective analysis was performed on 217 mammograms selected from approximately 40,000 screened women using a cluster sampling technique. A group of women with histologically proven breast carcinoma and two control groups were analysed. The incidence, site and pattern of axillary lymph nodes was compared in the three groups. The relative risk of the asymptomatic woman with axillary lymph nodes developing breast cancer was 1.08 times that of the asymptomatic woman without axillary lymph nodes. From these data we conclude that the presence of lymph nodes does not constitute a risk factor for the development of subsequent ipsilateral mammary cancer and should not influence the assessment of screening mammograms.

Adult↗