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Biomedical subjects

M R Adams

Publications and source records attributed to M R Adams.

At least 163 records · Page 9Linked to original sources
PubMed1982

Unheated serum reagin test as a quantitative test for syphilis.

The unheated serum reagin (USR) test, a standard qualitative test for syphilis, was evaluated for use as a quantitative test for the serodiagnosis of syphilis and as a means of determining the effectiveness of treatment. Tests were performed on 664 syphilitic sera from treated and untreated patients in the primary, secondary, and latent stages of the disease. Also included were 95 false-positive sera and 36 sera from presumably normal donors. The Venereal Disease Research Laboratory slide and rapid plasma reagin 18-mm circle card tests were used as a basis for comparison with the USR test. Results of the USR quantitative test paralleled the Venereal Disease Research Laboratory and rapid plasma reagin card quantitative tests with approximately 84% agreement. The advantages of the USR test make the findings of this study significant in that: (i) less technical manipulation is required to perform the USR test than the Venereal Disease Research Laboratory slide test; (ii) no labor cost is incurred for daily Venereal Disease Research Laboratory antigen preparation; and (iii) the USR antigen is less expensive than the rapid plasma reagin card tests antigen.

Antibodies↗
PubMed1981

Nitrous oxide alters oxidative metabolic activities of rat neocortex in situ.

Nitrous oxide was shown by dual wavelength reflection spectrophotometry to decrease the ratio of reduction/oxidation of cytochrome a,a3 and to increase local blood volume in the cerebral cortex of rats in situ. These changes were in contrast to the decreased local blood volume and increased reduction of cytochrome a,a3 produced by pentobarbital. These effects of nitrous oxide were similar to those produced by respiration of 95% O2 with 5% CO2 except that such inspiration resulted in hemoglobin oxygenation while N2O produced some disoxygenation of hemoglobin. We conclude that the N2O effect on metabolism is likely due to increased energy demand. These results also provide some indication that changes in oxidative functioning in brain tissues may occur without alteration in the concentrations of high energy phosphate compounds.

Animals↗
PubMed1981

The effect of pre-operative povidone iodine vaginal pessaries on vault infections after hysterectomy.

The frequency of clinical infection of the vaginal vault after hysterectomy was compared in two groups of patients, a study group treated with povidone-iodine vaginal pessaries for 36 hours pre-operatively and prepared with povidone-iodine preparations at the time of operation, and a control group given no preliminary treatment and prepared with chlorhexidine preparations at the time of operation. No significant difference was demonstrated between the two groups. Vault infection occurred in 32% of the entire series of patients (severe infection 14%) and infection correlated with the presence of pathogenic bacteria in the vagina. No significant differences in bacterial colonisation of the vagina between the two groups were demonstrated at any stage of the investigation. Preliminary preparation of the vagina with povidone-iodine pessaries is not recommended.

Adult↗
PubMed1981

Complicating factors in evaluating coronary artery atherosclerosis.

The most commonly used morphological descriptors of coronary artery atherosclerosis are cross-sectional intimal area and "percent stenosis." Cross-sectional intimal area, i.e. plaque area, describes lesion size, without normalizing for differences in arterial size. "Percent stenosis" describes the percentage of the area within the internal elastic lamina that is occupied by plaque. When using intimal area and percent lumen stenosis data from atherosclerosis regression experiments there may be interpretational difficulties not only in determining the extent to which atherosclerosis has regressed, but also in whether or not regression has occurred. Specifically, if there if a minimal decrease in intimal area, i.e. little or no regression of atherosclerisis, and the artery becomes larger, percent lumen stenosis will decrease, in some cases substantially, indicating improvement or "regression" of the disease. In experiments where the age, body and heart weights of baseline animals are different from those of the regression animals, part of the improvement that is seen in "percent stenosis" may be attributable to animal growth and part to an actual decrease in intimal area. A particularly interesting, complicating factor is the apparent effect of atherosclerosis on arterial size. In an atherosclerosis progression experiment we compared coronary arteries from cynomolgus monkeys fed either a control diet or an atherogenic diet for 36 months. Ages, body weights and heart weights were similar between the groups. The animals fed the atherogenic diet had much larger coronary artery intimal areas, but also had considerably larger coronary arteriese as indicated both by area enclosed by the internal elastic lamina and lumen area. These findings suggest that in growing animals atherosclerosis may result in increased arterial size and thereby complicate interpretations of atherosclerosis progression and regression experiments.

Animals↗
PubMed1980

Cerebral resistance to anoxia in the marine turtle.

The extraordinary ability of the turtle to withstand prolonged anoxia was examined in cerebral cortex in situ by recording changes in the reduction/oxidation ratio of cytochrome a,a3 by reflection spectrophotometry. Inspiration of 100% oxygen increased the oxidation of cytochrome a,a3 beyond that of the air breathing control, suggesting that cytochrome a,a3 is not fully oxidized under normoxic conditions in turtle brain. A similar response was seen also in cerebral cortex of the rat. The significance of the cytochrome a,a3 reduction in these intact tissues is discussed. Both severe hypoxia (100% N2) and asphyxia produced increasing levels of reduced cytochrome a,a3 in turtle and rat brains. The rat of change produced by N2 inspiration was greater than that produced by asphyxia in both species. This is interpreted as demonstrating an open pulmonary blood circulation during anoxia. In turtles, levels of reduced cytochrome a,a3 were maintained for over 3 h of continual N2 inspiration. Subsequent inspiration of room air resulted in a full restoration of turtle brain cytochrome a,a3 redox state within 30 sex. In the rat, continued N2 inspiration resulted in a rapid reduction of cytochrome a,a3 to a plateau (3 min) which became irreversible within a short period. An extended tolerance of N2 inspiration found in rats cooled to temperatures approximating that of the turtle was inadequate to account for the wide species of difference. We suggest that special adaptations, not related to the redox state of cytochrome oxidase under normoxic conditions, are responsible for maintaining the functional integrity and the capacity for cytochrome oxidase re-oxidation of turtle brain mitochondria under prolonged anoxia.

Animals↗
PubMed1980

Vocal characteristics of normal speakers and stutterers during choral reading.

It is well known that stutterers experience significant decrements in their stuttering when they read or speak in unison with another person. Recently, Wingate suggested that the act of choral reading or speaking prompts the individual who is following the model speaker to emphasize vocalization and its continuity throughout the utterance. This modified vocalization may then be viewed as the immediate cause of the stutterers' reduced disfluency. To evaluate this hypothesis, ten stutterers and ten normal speakers were tested in a control and choral reading condition. In the former, subjects read in their habitual manner. In the latter, subjects read in unison with a recording of a normal adult male. Subjects' oral readings were audio-taped and then submitted to spectrographic analysis. Measures of vowel duration, peak vocal SPL and continuity of phonation were made and then treated statistically. The major findings of this study indicated that across the two conditions, both groups failed to modify their vocal SPL and continuity of phonation. They did, however, alter their vowel durations. The normal speakers increased theirs by a statistically insignificant amount, while the stutterers significantly shortened theirs. The results that pertained to vocal SPL and vowel durations seemed a function of each group's scores for these measures in the control condition as compared to the values for the same measures that were generated by the model speaker with whom subjects read in unison in the experimental condition. These and other findings and interpretations are discussed further relative to Wingate's "modified vocalization" hypothesis.

Adolescent↗
PubMed1979

Voicing duration and vocal SPL changes associated with stuttering reduction during singing.

This study was conducted to determine if stuttering reduction during singing is associated with increased voicing duration and increased vocal SPL. Eight moderate to severe stutterers comprised the experimental group. Eight normal speakers, matched pairwise with the stutterers for sex and age, served as controls. Pre-experimental testing indicated that all subjects knew from memory the melody of the well-known song "Home on the Range." Subsequently, subjects were asked to read aloud and sing altered lyrics of this song to the conventional melody. Results showed that from reading to singing, disfluency frequency decreased significantly among the stutterers. Both groups of subjects significantly increased voicing durations across the two conditions, but only the normal speakers increased vocal SPL during song. These results indicated that the reduction in stutterers' disfluency (stutterings included) during singing was attended by an altered pattern of vocalization that included an increase in voicing duration, but no significant change in vocal SPL. These findings are discussed with reference to vocal tract dynamics, especially those that might promote higher levels of fluency among stutterers.

Adolescent↗
PubMed1979

Problems affecting performance of the fluorescent treponemal antibody-absorption test for syphilis.

Immunofluorescent staining of Treponema pallidum was studied to clarify the effect of three factors on the results of the fluorescent treponemal antibody-absorption test: (i) heat inactivation of sera at 56 degrees C for 30 min before testing, (ii) use of multicircle slides, and (iii) tungsten illumination to visualize and assess unstained treponemes on reactive as well as nonreactive smears. It was found that serum inactivation before testing was not necessary for detection of immunoglobin G antibody, but an immunoglobulin M prozone was detected in unheated serum. On multicircle slides, it was demonstrated that a false-positive reaction could be obtained in 30 s at 37 and 25 degrees C if a smear where a nonreactive serum had been placed was crossed by a strongly reactive serum from another circle. Tungsten illumination proved necessary for correct assessment of unstained treponemes on all fluorescent treponemal antibody-aborption test smears, reactive or nonreactive. The possible role of these factors in incorrect fluorescent treponemal antibody-absorption test results is discussed.

Antibodies, Bacterial↗
PubMed1979

Benign prostatic hyperplasia in a squirrel monkey (Saimiri sciureus).

Benign prostatic hyperplasia was diagnosed at necropsy in a middle-aged squirrel monkey (Saimiri sciureus). Grossly, the prostate gland was asymmetrically enlarged and had an irregular surface. Microscopically, both cystic glandular hyperplasia and fibromuscular, nodular hyperplasia were identified.

Animals↗
PubMed1978

Effects of two types of motor practice on stuttering adaptation.

The present study identifies and compares the effects of two types of motor practice on stuttering adaptation. The study was designed to determine if whispered reading practice affects stuttering adaptation, and if practice in reading aloud is superior to whispered reading in promoting adaptation. In a control condition, eight stutterers read one of two matched passages aloud five times in succession. In an experimental condition, the remaining passage was read aloud on the first and fifth trials, and was read in a whisper on Trials 2, 3, and 4. The results indicated that (1) the stutterers' adaptation in the control condition was similar to the typical course of adaptation, (2) the three intervening whispered readings in the experimental condition neither inhibited nor facilitated adaptation, and (3) practice in reading aloud was superior to whispered practice in promoting stuttering adaptation. It was concluded that whispered reading practice does not facilitate stuttering adaptation when the measurement of that process requires reading aloud. Traditionally, adaptation has been measured only during reading done aloud. Consequently, practice in reading aloud has the greatest positive influence on the adaptation process.

Adolescent↗
PubMed1978

Reproductive performance in a breeding colony of Brazilian squirrel monkeys (Saimiri sciureus).

In a captive colony of Brazilian squirrel monkeys (Saimiri sciureus) a discrete birth season has been retained for 5 years although its duration increased from 3 months in 1972 to 6 months in 1976. The ages of breeder females in this colony ranged from 3 to 14 years, and within this range reproductive performance was not affected by age, although it was significantly better in feral than in colony-born females. The latter had a lower pregnancy rate and a higher incidence of neonatal and fetal deaths than did the feral monkeys. It is our belief that the reproductive and maternal capabilities of the colony-born females were adversely affected by the practice of removing neonates from their mothers at weaning and raising them with age-mates.

Animals↗