Biomedical subjects
Publications and source records attributed to S M Johnson.
An overview of colonoscopy and polypectomy is presented. The merits of this procedure are pointed out, highlighting the newer technics and those technics that have survived. The complications of colonoscopy and polypectomy are reviewed in detail.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
An inhibitor of extraneuronal uptake, deoxycorticosterone acetate (DOCA), increased the sensitivities of the rabbit ear artery to extraluminal and to intraluminal epinephrine, each approximately threefold. The effect on extraluminal epinephrine was increased in cocaine-treated or chronic sympathetic denervated arteries. That the sensitising actions of DOCA were due to inhibition of extraneuronal uptake was suggested (1) by the relative magnitudes of its sensitising effects on the three amines [in decreasing order, epinephrine greater than isoprenaline (beta-stimulation) greater than norepinephrine] and (2) by its ability to prevent the potentiation of epinephrine by normetanephrine. That the uptake system was readily saturated was suggested by the observation that the sensitising actions of DOCA were decreased by procedures which decreased the potencies of epinephrine and isoprenaline, namely, phentolamine, and doses of isoprenaline eliciting constriction via alpha-stimulation, respectively.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
A study was designed to obtain information on the concerns, attitudes, beliefs, and knowledge that women have about reproduction in order to determine how these factors affect their ability to plan pregnancies. A clinical population was studied and in general found to be uninformed and misinformed about basic physiological facts relating to reproduction. Their lack of information or their misinformation about the menstrual cycle, safe time for intercourse, and contraception contributed to unwated pregnancies. They did not know enough to prevent pregnancy. The patients were aware of some deficits in their knowledge about reproduction and expressed a desire to learn more. This study suggests that individualized education may be necessary to break the pattern of unwanted pregnancies and the feelings of apathy and fatalism so common among low-income patients.
A study was designed to gain information on the concerns, attitudes, beliefs, and knowledge that women have about reproduction to determine how these affect their health practices during pregnancy. A low-income multiethnic clinic population was studied in which the majority of the patients were in a high-risk category for pregnancy. They often failed to follow suggested regimens and/or engaged in negative health behaviors. Interviews with patients revealed that they too identified a number of risk factors in pregnancy, but that there was a disparity between their perceived risks and those of concern to the clinic staff. Many of the problems ascribed to patient noncompliance may be attributable to this differential perception of what constitutes a danger to pregnant women. In clinical settings where patients and professionals are divided by social class and cultural differences, it is suggested that physicians be aware of such beliefs so that patients may be reeducated to improve pregnancy outcomes.
To experimentally investigate the effect of excess body weight or fat on maximal oxygen uptake (Vo2 max) and distance running performance, the metabolic response to maximal and submaximal treadmill running and the 12-min run performance were measured in six subjects under each of four added-weight (AW) conditions: normal body weight and 5, 10, and 15% additional external weight, added to the trunk. AW was found to systematically and significantly decrease Vo2 max expressed relative to the total weight carried (ml/min.dg TW), maximal treadmill (TM) run time and 12-min run distance, but not to systematically affect Vo2 max (1/min) or Vo2 max (ml/min.kg FFW). An increase of 5% AW was found, on the average, to decrease Vo2 max (ml/min.kg TW) 2.4 ml, the TM run time 35 sec and the 12-min run distance 89 m. These decreases were a direct consequence of the increased energy cost of running at submaximal speeds. It was concluded that changes in excess body weight can influence Vo2 max expressed relative to body weight and distance run performance independent of any change in cardiovascular capacity. Failure to distinguish the metabolic effects of body fatness from the influence of cardiorespiratory capacity may result in misleading interpretation of distance run test scores.
Clinicians are often unaware of the folk medical beliefs of their patients or consider them to be harmless and unimportant. Such beliefs are instrumental in shaping patient behavior, however, and may contribute to negative health practices. The information presented here demonstrates that attitudes toward a single bodily function, menstruation, may adversely affect women's body image, perception of disease causation, diet, willingness to take medication, contraceptive use, and the ability to plan pregnancies. The data are part of a pilot study in which patients in a clinic serving a multiethnic low-income population were questioned about their knowledge and beliefs concerning the female reproductive cycle. It is concluded that health personnel should strive to learn what women know and believe about their bodies and how they function, to improve health care provision.
Explore the source record for details and available documents.
The mean activity of purine 5'-nucleotidase (E.C.3.1.3.5) in lymphocytes was significantly lower in patients with non-familial adult onset "variable" primary hypogammaglobulinaemia than in non-hypogammaglobulinaemic control subjects. These findings suggest that 5'-nucleotidase activity is necessary for normal lymphocyte function. This may be related to its role in facilitating the transfer of newly formed purines across cell membranes by converting them from nucleotides to nucleosides. This enzyme defect may be a characteristic metabolic lesion in at least some of the patients; alternatively, it may be secondary to some other metabolic defect or plasma-membrane change.
When assayed on homogenates of the rabbit ear artery up to 192 h after sympathetic denervation, the activity of monoamine oxidase (MAO) showed a small but significant decrease (maximum 9%). The activity of catechol-O-methyl transferase (COMT) appeared unchanged, although it is possible that the small and variable nature of this enzyme activity compared with that of MAO may have masked a comparable effect of denervation. The maximum decreases in noradrenaline (NA) and adenosine triphosphate (ATP) contents were greater than 90% at 48 h, and 32% at 96 h after denervation. These results confirm the presence of neuronal as well as extra-neuronal MAO, and also the presence of extraneuronal comt in this artery. The decline in ATP contents after denervation suggest that part of the ATP is neuronal. However, the estimated ratio of NA to neuronal ATP is far in excess of that reported for isolated noradrenaline storage vesicles, suggesting that the major portion of the neuronal ATP was not present in these vesicles.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Eikenella corrodens was isolated from an orally contaminated hand wound which resulted in cellulitis, osteomyelitis, and arthritis. E corrodens is a gram-negative, microaerophilic bacillus which only lately has received attention as a possible pathogen. The organism grows characteristically as small, corroding, or pitting colonies on blood agar. It typically requires hemin or blood for reliable aerobic growth. Oral contamination of wounds predisposes to infection with E. corrodens. The management of these infections includes treatment with an effective antibiotic and surgical debridement. Because it is gram-negative, microaerophilic, and often difficult to isolate, infections caused by E corrodens may mimic those caused by gram-negative obligate anaerobes. However, E corrodens is resistant to clindamycin and lincomycin and sensitive to most other commonly used antimicrobial agents.
Five children referred to a child-family intervention program wore a radio transmitter in the home during pre-intervention and termination assessments. The transmitter broadcast to a receiver-recording apparatus in the home (either activated by an interval timer at predetermined "random" times or by parents at predetermined "picked" times). "Picked" times were parent-selected situations during which problems typically occurred (e.g., bedtime). Parents activated the recorder regularly whether or not problems occurred. Child-deviant, parent-negative, and parent-commanding behaviors were significantly higher at the picked times during pretest than at random times. At posttest, behaviors in all three classes were substantially reduced at picked times, but not at random times. For individual subject data, reductions occurred in at least two of the three dependent variables for three of the five cases during random time assessments. In general, the behavioral outcome data corresponded to parent-attitude reports and parent-collected observation data.
Measurement of the cation permeability of phospholipid microvesicles as a function of pressure confirmed that a single rate-determining step occurred in each case. The volume of activation was 20 ml-mole minus 1 for Na+ and K+, and about 40 ml-mole minus 1 for valinomycin-mediated K+ permeability. It was virtually independent of membrane composition. The results were explained in terms of Träuble's theory of kink-substrate dissociation at the membrane interface involving possible 2gl and 2g2 kink isomers. The volume of activation for D-glucose was 37 ml-mole minus 1, which was not significantly different from that for any of the valinomycin-mediated K+ permeabilities. However, other data suggest that the rate-limiting steps for the sugar and cation permeabilities are not the same.