Search PubMed⌕ Search

Biomedical subjects

T Smith

Publications and source records attributed to T Smith.

At least 883 records · Page 49Linked to original sources
PubMed1970

Propulsion (mass movements) in the human colon and its relationship to meals and somatic activity.

Propulsive activity of the human colon was measured with radiopaque markers (shapes), radiotelemetering capsules, Perspex capsules containing (51)Cr, or with free (51)Cr sodium chromate. Propulsive activity can be readily detected by these techniques, none of which requires the use of radiological contrast media. With capsules containing (51)Cr or with free (51)Cr repeated observations can be made in the same patient without recourse to radiography. The patient can remain normally active during the test with encapsulated (51)Cr. Repeated observations may also be made with shapes, if films exposed at low mA are used. It was found that colonic intraluminal pressure activity rises markedly during and after food, but that in the resting patient this increase is rarely associated with propulsive activity. In physically active patients propulsion of colonic contents was significantly increased after meals. When colonic propulsion takes place, it does so by a series of mass movements. These results suggest that somatic activity is an important factor in the control of colonic transit in health or disease.

Adult↗
PubMed1969

Measurement of blood and iron loss in colitis with a whole-body counter.

Estimation with a whole-body counter of the fall in total body radioactivity due to loss of parenterally administered (59)Fe has been used to measure blood loss in 17 patients with ulcerative colitis. It was shown that blood loss was related to the activity of disease as judged by sigmoidoscopic changes and less obviously to the extent of involvement of the colon. Blood losses of 50 to 150 ml per week were observed when the patient saw no blood in the stools and the rectal mucosa did not appear haemorrhagic. Some patients lost more than 0.5 g iron during the few weeks following an exacerbation of ulcerative colitis suggesting that repeated replacement of the body's iron stores is often necessary in this disease.

Adult↗
PubMedDate not supplied

Molecular analysis of human muscular dystrophies.

The ability to map disease loci using restriction fragment length polymorphisms (RFLPs) identified by DNA probes has revolutionized molecular genetics. Duchenne and Becker muscular dystrophies have been shown to be localized within the same very small region of Xp21 on the human X chromosome. The mutation itself should soon be identified at the DNA level, which will permit a detailed analysis of the molecular defect at the biochemical level. Rapid progress has also been made in the study of myotonic dystrophy on chromosome 19. DNA markers closely linked to the mutant locus have been identified, making antenatal diagnosis possible in informative families. Autosomal recessive muscular dystrophies are more difficult to study, but the means to localize even these mutations is being developed. The next decade should prove to be an exciting one for those involved in the molecular analysis and clinical management of human muscular dystrophies.

Chromosome Mapping↗
PubMedDate not supplied

Field applications of agglutination and cytoadherence assays with Plasmodium falciparum from Papua New Guinea.

Plasmodium falciparum isolates obtained directly from patients in Papua New Guinea were tested in their first cycle of growth in vitro for adherence to melanoma cells and for susceptibility to agglutination by immune serum. Binding varied among isolates and, in many cases, increased with further rounds of replication under optimal culture conditions. Binding inhibition assays and agglutination assays demonstrated extreme heterogeneity of surface antigens; apparently none of the sera from adult patients recognized all of the variants presented.

Adult↗
PubMedDate not supplied

Malaria: how useful are clinical criteria for improving the diagnosis in a highly endemic area?

To assess the validity of clinical criteria, we investigated 2096 outpatients diagnosed as malaria cases by nurses at a rural health subcentre in a highly endemic area of Papua New Guinea. 73% of the children < 10 years old had a positive blood slide for any species of Plasmodium and 32% had > or = 10,000 P. falciparum parasites per microL. For adults the frequencies were 51% and 9%, respectively. Stepwise logistic regression identified spleen size, no cough, temperature, no chest indrawing, and normal stools as significant predictors for a positive blood slide in children; no cough and normal stools predicted a positive blood slide in adults. Fever, no cough, vomiting, and enlarged spleen were significant predictors for a P. falciparum parasitaemia > or = 10,000/microL in children; in adults the only predictor was vomiting. In children the association of no cough and enlarged spleen had the best predictive value for a positive blood slide, and a temperature > or = 38 degrees C had the best predictive value for a P. falciparum parasitaemia > or = 10,000 microL. In adults, no major symptom had a good predictive value for a positive blood slide but vomiting had the best predictive value for a P. falciparum parasitaemia > or = 10,000/microL. When microscopy is not available, these findings can help in areas of high endemicity to determine which patients with a history of fever are most likely to have malaria and, more importantly, for which patients another diagnosis should be strongly considered.

Adolescent↗