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Biomedical subjects

J W Thorpe

Publications and source records attributed to J W Thorpe.

32 records · Page 2Linked to original sources
PubMed1993

Spinal cord MRI using multi-array coils and fast spin echo. I. Technical aspects and findings in healthy adults.

It is time-consuming to detect intrinsic spinal cord lesions in multiple sclerosis (MS) by MRI using conventional surface coils and T2-weighted spin-echo pulse sequences. Multi-array coils and fast spin-echo pulse sequences permit the generation of high-resolution T2-weighted sagittal images of the whole spinal cord in about 5 minutes. Using these advances, we found an area of high signal within the cord in only 1/45 (2%) healthy subjects aged 18 to 72 years, whereas 26% of those who underwent brain imaging had cerebral white matter abnormalities. Degenerative vertebral column changes, especially in the cervical region, were present in 64% and were associated with cord compression in 11%. Cord cross-sectional areas in mm2, measured from axial gradient-echo images, were usually highly reproducible and showed a significant correlation with the subject's height. We conclude that (1) MRI signal abnormalities within the spinal cord may be more specific for MS than cerebral white matter lesions, especially in subjects over 50 years old; (2) asymptomatic degenerative changes in the vertebral column are common, even in younger adults; (3) measurement of cord cross-sectional area should allow accurate quantitation of the degree of atrophy in MS and other spinal cord diseases; and (4) multi-array coils and fast spin echo represent an important advance in MRI of the spinal cord.

Adolescent↗
PubMed1993

Spinal cord MRI using multi-array coils and fast spin echo. II. Findings in multiple sclerosis.

We performed MRI of brain and spinal cord on 80 patients with multiple sclerosis (MS). Using multi-array coils and fast spin echo, 139 intrinsic lesions were identified in 59 patients (74%). Lesions were more common in the cervical than in the thoracic cord. Cross-sectional areas of the cord, measured from axial images at four levels, showed atrophy in 40%. Clinical disability correlated with cord atrophy but not with cord lesion load. These results show that the use of multi-array coils and fast spin echo allows rapid and sensitive detection of spinal cord lesions in MS and that the cord is involved in the majority of patients. A lack of association between cord lesions and disability may relate to limitations in MR resolution but also suggests that the mechanisms of disability in MS are complex and multifactorial.

Adult↗
PubMed1992

Acute polyneuropathy due to lightning injury.

The case of a 19 year old man struck by lightning is described. He sustained quadriplegia for several months and fully recovered. It is suggested that his weakness was due to extensive peripheral nerve damage. In addition, he displayed many well recognised medical complications of lightning injury including acute renal failure, rhabdomyolysis, respiratory distress syndrome, autonomic dysfunction, perforated ear drum, uveitis and cataract. The literature relating to the neurology of lightning strike is briefly reviewed.

Acute Disease↗
PubMed1986

Enzyme-linked immunosorbent assay for A and B water soluble blood group substances.

The conditions affecting an enzyme-linked immunosorbent assay for salivary blood group substances were investigated. It was found that A, B, and O secretor saliva samples would each bind both anti-A and anti-B typing reagents. The conditions that affected the assay response were optimized for maximum sensitivity and to give the highest resolution possible between the result for an antiserum binding to homologous antigen and the response for heterologous antigen-antibody combinations. Monoclonal antibodies eliminated the heterologous binding indicating that this binding was due to a lack of specificity of the routine typing reagents. A sensitive assay using the monoclonal antibodies to distinguish between samples of A and B secretor saliva is described.

ABO Blood-Group System↗
PubMedDate not supplied

Macroscopic and microscopic assessments of disease burden by MRI in multiple sclerosis: relationship to clinical parameters.

We have evaluated macroscopic white matter abnormalities (visible lesions) together with microscopic abnormalities in the normal appearing white matter (NAWM) of patients with multiple sclerosis (MS) to determine their relative contributions to the development of disability. The total visible lesion volume (TLV) was computed as a measure macroscopic changes, whereas both texture analysis and T2 were used as possible indicators of diffuse disease in the NAWM. Dual echo T2-weighted SE images were obtained from 41 patients with definite MS: 10 primary progressive (PP), 11 secondary progressive (SP), 10 benign (BE), 10 early relapsing remitting (ERR), as well as from 10 healthy controls. Calculation of T2 and texture parameters were performed in a region of frontal NAWM of patients and controls. The TLV of each patient was measured using a semiautomated lesion detection program. No significant differences were found between the controls and the patients for all texture parameters examined. However, NAWM T2 was longer in the patients than in the controls (P = .02). Mean TLV was highest for SP and lowest for BE and ERR patients. A significant correlation was found between TLV and EDSS (P < .01) but not between NAWM T2 or texture and expanded disability status score (EDSS). Our study suggest that: (a) diffuse changes are present in NAWM, (b) texture analysis is unable to detect any subtle structure in the NAWM abnormalities, possibly because of the limited image resolution; (c) in the development of disability in MS, macroscopic lesions are more important than microscopic abnormalities in the NAWM.

Adult↗
PubMedDate not supplied

Comparison of Cannabis sativa by random amplification of polymorphic DNA (RAPD) and HPLC of cannabinoids: a preliminary study.

Methods are described for the HPLC and genetic analysis of herbal Cannabis sativa. The latter method was applied to 17 plants grown simultaneously, at the same site. Sixteen of these samples were also compared using HPLC, which resulted in differentiation of the plants into 3 groups. Within two of these groups, the members could not be distinguished. By RAPD analysis, using certain combinations of primers and cladistic analysis, differentiation was possible between all but two of the plants. The use of the RAPD technique enables differentiation between samples that cannot be differentiated by HPLC analysis alone.

Base Sequence↗