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Biomedical subjects

D Harris

Publications and source records attributed to D Harris.

At least 19 recordsLinked to original sources
PubMed1979

Detection of antibody-forming cells and humoral antibody to horseradish peroxidase.

Two new simple methods for detecting antibody-forming cells by hemolytic plaque assay and hemagglutinating antibody to horseradish peroxidase have been developed in mice. Both techniques utilize as target, sheep erythrocytes coupled directly with horseradish peroxidase. These assays are sensitive, antigen-specific and are useful to quantitate both direct and indirect antibody-forming cells and humoral antibodies.

Animals↗
PubMed1979

A simple method for correcting left ventricular equilibrium radionuclide angiography for the effects of arrhythmias.

A simple method of correcting equilibrium radionuclide angiographic data for the effects of arrhythmias is proposed. This involves no further acquisition time or inconvenience to the patient. This correction is necessary in patients with marked arrhythmias as the left ventricular time-activity curve (LVTAC) becomes distorted with greater sampling time in the first few frames of the LVTAC than in later frames. This will show on the LVTAC as greater counts in the first few frames and will lead to an overestimation of left ventricular ejection fraction (LVEF) and wall motion. The method proposed normalises each frame to make the contribution from a non-cardiac region constant over the cardiac cycle. Results of the correction are presented and discussed.

Arrhythmias, Cardiac↗
PubMed1979

Lysozyme in the tears of newborn babies.

Tear lysozyme concentration was measured in term, preterm, and small-for-dates infants using a modification of the lysoplate technique. The lysozyme concentration was greater in the term infant than in preterm and small-for-dates infants. The values were found to increase with birthweight and gestation to a term value which is similar to that described in adults. There was no relationship between the lysozyme concentration and the rate of tear production.

Birth Weight↗
PubMed1979

Suicide in pregnancy: the Hedda Gabler syndrome.

A review of forty-seven suicides in women of child-bearing age revealed that two women were pregnant, two were within the first year post-partum and two falsely believed themselves pregnant. The search revealed two additional pregnancy-associated suicides which had not been reported as suicide. Previous studies asserting that pregnancy protects against suicide would seem to be challenged by these data. Pregnancy-related suicides are similar to each other and to the literary suicide of Hedda Gabler and fit into a continuum of pregnancy-related disorders.

Adult↗
PubMed1978

Survivorship from large bowel cancer among Caucasians and Japanese in Hawaii.

From 1960 through 1973, the Hawaii Tumor Registry identified 781 Caucasian and 1073 Japanese cases of large bowel cancer. Survivorship analysis revealed that Japanese patients had a 32% higher 5-year relative survival rate than Caucasians. Further analyses showed that colon cancer cases did better than rectal cases, and patients diagnosed before 65 years of age fared better than cases diagnosed at an older age. As expected, patients with localized disease lived much longer than those who had more advanced disease. Men and women were similar in their survival from large bowel cancer. Histologic grade of the lesion, socioeconomic variables, behavioral practices and other factors which may affect survivorship by race could not be included in this study. Until such factors are also incoporated in the analyses, the observed results are only suggestive of a racial difference in survivorship.

Age Factors↗
PubMed1978

Behavioral, compound action potential, and single unit thresholds: relationship in normal and abnormal ears.

Comparisons were made for two species (chinchilla and mongolian gerbil) among mean behavioral audiogram, mean just detectable action potential (AP) responses to tone bursts, and single-fiber response thresholds at the characteristic frequency, averaged in one-octave bands. In normal animals and in a group of Kayamycin-treated chinchillas, these mean measures appear to have a well-ordered relationship. Unit and AP thresholds are within 10 dB from one another throughout the frequency range. Behavioral thresholds are usually 15--20 dB more sensitive, but the three curves are roughly parallel except at the highest frequencies, where the behavioral threshold begins to increase approximately one-half octave above the physiological ones. Individual examples for four gerbils and four chinchillas having hair cell losses due to Kanamycin intoxication reinforce the notion based on mean data that in most cases AP thresholds can serve to predict the behavioral threshold configuration.

Action Potentials↗
PubMed1978

Properties of auditory nerve responses in absence of outer hair cells.

1. Recordings were made from chinchilla auditory nerve fibers after portions of the cochlear outer hair cell (OHC) population were destroyed with the antibiotic kanamycin. In most cases the inner hair cell (IHC) population was completely preserved as determined by phase-contrast microscopy. We presume that the remaining IHCs are functionally normal, and thus that recordings obtained from fibers originating from the lesioned cochlear segment reflect IHC behavior. 2. Behavioral thresholds were measured for all animals both before and after the production of the cochlear lesion. The audiograms and the histological evaluation of the ears were the basis for assessing whether a particular fiber originated in a normal, pathological (shifted threshold; IHC only), or border region. These criteria also identified the animals that sustained IHC damage together with the destruction of part of the OHC population. Only the data obtained from those fibers which probably originated from the OHC-free segment of the cochlea are considered in detail. 3. Fibers whose characteristic frequency (CF) identified them as belonging to the normal (audiometrically and histologically) region, were found to be normal in all respects. 4. Fibers from the border region (where the audiogram has a steep slope between normal and hearing-loss regions probably corresponding to the segment where OHC loss progresses from less than 10% to more than 90%) had very complex response patterns. Their frequency threshold curves (FTC) showed great variability. In general, the closer the fiber was to the fully developed lesion, the more abnormal its FTC became. 5. Those units that were concluded to have originated from the OHC-free part of the cochlea could be divided into three categories on the basis of the shape of their FTCs. A small fraction had very broad tuning (9%). The majority (53%) had approximately normal tail segment, normal bandwidth of the tip segment, and highly elevated threshold at CF. A group of fibers (38%) could not be assigned a CF. Probably the FTC of most of these latter fibers are similar to those of the previous group, but the sharply tuned short tip segment was either missed or was not reachable on account of its extremely high threshold level. 6. Such indexes of fiber response as latency, spontaneous rate, and time pattern (PST histograms) were not affected by the loss of OHCs. 7. On the basis of the data and of the assumptions made it was suggested that outer hair cells provide a frequency-dependent sensitizing influence to the inner hair cells. The frequency dependence could best be expressed as a flat-topped band pass characteristic.

Acoustic Stimulation↗
PubMed1977

A computer-assisted, goal-oriented psychiatric progress note system.

The authors describe a computer system that develops a structured progress note for inclusion in the medical record. The progress note system reflects a goal-oriented patient treatment process and also provides for retrospective analysis of progress note information to accommodate research and review objectives. The system, which has met with a high degree of clinician acceptance, has resulted in improved case documentation, more timely and comprehensive notes, a higher level of objectivity, and a considerable reduction in the time required to organize and record progress note data.

Computers↗
PubMed1977

Patterns of cystine reduction by fibroblasts from normal and cystinotic children.

The possibility that the enzymatic reduction of cystine involves a multi-enzyme system led to re-evaluation of cystine reduction by fibroblasts from normal and cystinotic patients. Lineweaver-Burk plots of data with extracts of a normal cell line, representative of seven normal cell lines, under conditions of increasing cystine with variable levels of reduced glutathione (GSH) resulted in a two-limbed curve above 100 micronM cystine. Two cell lines from children with nephropathic cystinosis containing 1-6 micronmol half-cystine/g protein gave a family of curves similar to those of the normal. With six fibroblast lines containing more than 6 micronmol half-cystine/g protein, increasing cystine resulted in a family of lines without two-limbed curves. Plots of the data as activity against increasing cystine concentrations at ratios of cystine to GSH of 1:2 and 1:1 showed that two of the three lines from cystinotic subjects reduced cystine at a faster rate than the normal line. The third line from a cystinotic patient reduced cystine at a slightly slower rate when the substrate concentration in the assay was less than 80 micronM cystine. When the cystine to GSH ratio was maintained at 2:1, normal cells showed a linear increase in the rate of cystine reduction up to 100 micronM cystine, no increase in the rate between 100 micronM and 200 micronM cystine, and an increase again when the concentration of cystine was raised above 200 micronM. Such a stepwise phenomenon was absent with six cell lines containing more than 6 micronmol half-cystine/g cellular protein. A possible mechanism of control of cystine reduction is discussed.

Cell Line↗