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Biomedical subjects

H C Miller

Publications and source records attributed to H C Miller.

At least 127 records · Page 7Linked to original sources
PubMed1975

Electrophysiological evaluation of the Wolff-Parkinson-White syndrome: problems in assessing antegrade and retrograde conduction over the accessory pathway.

The effect of atrial pacing and recording site and ventricular pacing site on assessment of conduction over the accessory pathway (AP) was examined in a group of patients with the Wolff-Parkinson-White syndrome. The importance of initial localization of the AP by recording the sequence of retrograde atrial activation during circus movement tachycardia is demonstrated. Inability to record or pace near the AP may lead to significant errors in the assessment of the antegrade and retograde conduction properties of the AP. During ventricular pacing, retrograde atrial fusion was consistently demonstrated with laterally located APs.

Cardiac Catheterization↗
PubMed1975

Refractory periods of the accessory pathway in the Wolff-Parkinson-White syndrome.

Antegrade (AERPAP) and retrograde (RERPAP) effective refractory periods of the accessory pathway were measured at multiple cycle lengths in 47 patients with the Wolff-Parkinson-White syndrome. In 20 patients the effect of changing cycle length on AERPAP could be determined. In 12 patients Aerpap decreased by 10-45 msec, in six it increased by 10-35 msec, and in two it was unchanged. In 13 of 15 patients in whom the effect of decreasing cycle length on RERPAP could be assessed, RERPAP decreased by 10-60 msec. In eight patients, the shortest AERPAP correlated well (r equals 0.83) with the shortest R-R interval of consecutive pre-excited beats in atrial fibrillation. However, predominantly normal conduction was observed in six of 28 patients with atrial fibrillation, probably because of concealment in the bypass. Therefore, induction of atrial fibrillation during electrophysiological evaluation may privide additional information. The RERPAP at the cycle length of the arrhythmia was shorter than the cycle length of reciprocating tachycardia in all but one of 21 patients. At the same or comparable cycle lengths, AERPAP was usually greater than RERPAP.

Adolescent↗
PubMed1975

Contact sensitivity in mice measured with thymidine labeled lymphocytes.

An ear assay was used to detect delayed responses in mice. Animals were sensitized and subsequently injected with 3H thyminedeoxyryribose to label antigen sensitive cells. Each animal was given a control and a test ear challenge and the respective responses were assessed by scintillation counting of 3H in cells which had accumulated at the reaction site. Delayed responses were consistently observed in animals sensitized to dinitrochlorobenzene (DNCB) but not in animals sensitized to sheep red blood cells. Reactivity to DNCB was minimal in tolerant animals and animals sensitized to the control agent. Both peritoneal exudate and spleen cells of antigen-sensitized animals were found to contain more label than cells from non-sensitized animals.

Animals↗
PubMed1975

Modulation of the immune response by antigen-reactive lymphocytes after cultivation with gangliosides.

GM1 ganglioside isolated from mouse brain was found to be capable of inhibiting the thymocytotoxicity of AKR anti-Thy 1.2 antiserum and to a lesser extent anti-BAtheta antiserum. GD1b ganglioside of mouse brain and thymocytes inhibited the thymocytotoxicity of rabbit anti-BAtheta anti-serum for mouse thymocytes. When GM1 ganglioside, in the form of cholesterol-lecithin liposomes, was incubated with spleen cell cultures in the presence of SRBC, depressed anti-SRBC hemolytic plaque responses were observed. This effect could be neutralized by first absorbing the GM1 liposomes with anti-Thy-1.2 antibodies. The kinetics of GM1 numbers when the ganglioside was added even as late as the 4th day of culture. Results of experiments in which GM1 ganglioside was incubated with either bone marrow cells or with thymocytes suggest that the target cell for GM1 liposomes is the B lymphocytes.

Animals↗