PubMed Health⌕ Search

Biomedical subjects

J Dutton

Publications and source records attributed to J Dutton.

15 recordsLinked to original sources
PubMed1992

Regional distribution of ECS in contractile and conductive elements of rat and rabbit heart.

By adaptation of recently developed quantitative microanalytic techniques, the size of the extracellular space (ECS) was measured regionally in the rat and rabbit cardiac conductive and contractile tissues. When inulin and sucrose were measured as extracellular markers in rabbit heart, the ECS in the atrioventricular (AV) node was found to be, respectively, 2.4 and 2.2 times larger than that of adjacent ventricular muscle. By use of inulin, the ECS in the rabbit His bundle was found to be 1.8 times larger than the adjacent ventricular tissue. Similarly, when inulin was used in rat, the ECS of the AV node, His bundle, right bundle branch, and right atrium was found to be, respectively, 2.5, 1.9, 1.8, and 1.2 times larger than that of left and right ventricular muscle. Similarly, significant regional differences in ECS were also observed in rat heart with sucrose. By use of glucose as an ECS marker, these results also revealed a 2.5-2.9 times larger ECS in rat and rabbit AV node compared with contractile elements. In contrast, ATP content, measured as an intracellular marker, was the same in both AV nodal and ventricular muscle tissue from both rat and rabbit. These data demonstrate that there are significant regional variations in ECS within the cardiac conduction system. Collectively, the data obtained with all extracellular markers indicate that the size of the ECS of the conduction system is markedly larger than the adjacent contractile muscle.

Adenosine Triphosphate↗
PubMed1992

Pyrophosphate in synovial fluid and urine and its relationship to urinary risk factors for stone disease.

Inorganic pyrophosphate (PPi) measurement in urine and synovial fluid has been established using the PPi-dependent phosphorylation of fructose-6-phosphate and subsequent reduction of dihydroxyacetone phosphate by NADH. The assay is linear up to 200 mumol/L, easy to perform and gives results comparable to more complex methods. Daily urinary output of PPi was independently related to both age (P = 0.0014) and sex (P = 0.0002). Men had higher values than women and older individuals excreted greater amounts. Male stone formers, younger than 45 years, had lower values than age matched male controls (P = 0.012). Younger female stone formers also tended to have lower values. In stone formers' urine significant and independent correlations were found of PPi excretion with urine volume (P = 0.004) and with phosphate excretion (P = 0.008). Oxalate excretion and that of other urine constituents and the degree of supersaturation with common stone-forming salts were not correlated with PPi. PPi excretion was markedly elevated in the urine of two patients with hypophosphatasia. The PPi concentration in synovial fluid from painful, swollen knee joints was elevated, but unrelated to the presence or absence of PPi or urate crystals.

Adolescent↗
PubMed1991

Measurement of extracellular space in the rabbit AV node.

We used quantitative histochemistry to measure the size of the extracellular space (ESC) in various regions of the rabbit heart. When inulin, sucrose, and sorbitol were used as ECS markers, the ECS of the AV-nodal tissue was found to be, respectively, 2.4, 2.2, and 2.5 times larger than that of left ventricular muscle. Glucose was also measured over a 50-fold serum concentration range as an extracellular marker for AV-nodal tissue, left ventricular muscle, and Purkinje fibers. Measurements with glucose also revealed that the ECS of the AV node was 2.5-2.8 times larger than that of ventricular muscle. In contrast, the ECS of the AV node was the same as that of Purkinje fibers when glucose was used as an extracellular marker. ATP content, measured as an intracellular marker, was similar in both AV-nodal and contractile tissue. Collectively, the data obtained with all extracellular markers indicate that the ECS of the AV-nodal region is approximately 2.5 times larger than that of adjacent contractile tissue. Differences in the size of the ECS in various regions of the heart probably have functional significance and should be considered appropriately during the interpretation of data obtained by biochemical and densitometric approaches.

Acetylcholinesterase↗
PubMed1990

Determination of total body calcium by prompt gamma neutron activation analysis: absolute in vivo measurements.

Sequential TBCa measurements using the prompt gamma ray technique are firmly established and a number of patient groups are under investigation. A technique has been proposed for the absolute measurement of TBCa based upon the use of TBCl as an internal standard. Further work is needed to establish the validity of the method, but the initial results are encouraging.

Body Composition↗
PubMed1978

Intracranial solitary chondroma. Case report.

A case of massive solitary intracranial chondroma involving the base of the skull in a 15-month-old baby boy was successfully treated by total excision. The diagnosis was greatly simplified by the us of computerized tomography, which materially helped in planning the surgical approach.

Brain Neoplasms↗
PubMed1978

Hodgkin's disease.

Explore the source record for details and available documents.

Hodgkin Disease↗
PubMed1975

Prognosis in colon cancer: a pathologic reassessment.

One hundred forty-eight cases of colon carcinoma were subjected to further pathologic study. Survival was correlated with stage and grade of the tumor and with the number of involved lymph nodes. In addition, cases were assessed as to the extent of local chronic inflammatory reaction about the lesion and the degree of sinus histiocytosis in draining lymph nodes. A correlation was possible between grading, staging, extent of lymph node involvement, and survival. A substantial difference in five-year survival was shown when local inflammatory reaction was present and when sinus histiocytosis was observed. The presence of both of these factors further improved survival. An adequate evaluation of these factors, both individually and in combination, should improve our ability to assess prognosis in colon cancer.

Adenocarcinoma↗
PubMedDate not supplied

Measurements of total body calcium by prompt-gamma neutron activation analysis using a 252Cf source.

A clinical neutron activation instrument has been developed for in vivo elemental analysis. Utilizing the prompt-capture gamma ray technique, simultaneous total body (TB) measurements of primarily Ca, but also Cl, N, C, and H are routinely performed. This paper describes a technique for the measurement of TBCa (g) that relies on the use of TBCl as an internal standard. The method has been tested with four anthropomorphic phantoms covering a range of body habitus. The mean discrepancy between the measured and known Ca contents was 3.6%. The technique has been applied to two patient groups, and encouraging results were obtained.

Body Composition↗