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Biomedical subjects

A Christensen

Publications and source records attributed to A Christensen.

At least 91 records · Page 5Linked to original sources
PubMed1983

Parental characteristics and interactional dysfunction in families with child behavior problems: a preliminary investigation.

Thirty-six families with a preteenage behavior problem child were assessed on measures of marital discord, parental psychopathology, and three parental cognitive factors: knowledge of behavioral principles, tolerance for child deviancy, and expectations regarding their child's behavior. Nine nonproblem families with demographic characteristics similar to the problem families were also assessed. Correlational analyses across all families revealed a strong association between marital discord and the parental index of child behavior problems. While a number of significant associations were discovered between the various measures of marital discord, parental psychopathology, and parental cognitive factors, no other measure besides marital discord was associated with parental perception of child behavior problems. The nonproblem families and 15 of the problem families also participated in home observations obtained through random audio recordings during high interaction periods. These observational data indicated a significant relationship between parental perception of child behavior problems and parental negative behavior toward the child, but no significant relationship between parental perception of child behavior problems and child behavior, even when child behavior was weighted by parents' reactions to that behavior. Through sequential analysis, several contingent relations between parent and child behavior were discovered. Findings are discussed in relation to family systems theory.

Aggression↗
PubMed1982

Binding site of ribosomal proteins on prokaryotic 5S ribonucleic acids: a study with ribonucleases.

The binding sites of ribosomal proteins L18 and L25 on 5S RNA from Escherichia coli were probed with ribonucleases A, T1, and T2 and a double helix specific cobra venom endonuclease. The results for the protein-RNA complexes, which were compared with those for the free RNA [Douthwaite, S., & Garrett, R. A. (1981) Biochemistry 20, 7301--7307], reveal an extensive interaction site for protein L18 and a more localized one for L25. Generally comparable results, with a few important differences, were obtained in a study of the binding sites of the two E. coli proteins on Bacillus stearothermophilus 5S RNA. Several protein-induced changes in the RNA structures were identified; some are possibly allosteric in nature. The two prokaryotic 5S RNAs were also incubated with total 50S subunit proteins from E. coli and B. stearothermophilus ribosomes. Homologous and heterologous reconstitution experiments were performed for both RNAs. The effects of the bound proteins on the ribonuclease digestion of the RNAs could generally be correlated with the results obtained with the E. coli proteins L18 and L25, although there was evidence for an additional protein-induced conformational change in the B. stearothermophilus 5S RNA, which may have been due to a third ribosomal protein L5.

Bacterial Proteins↗
PubMed1978

Bacteriuria in the puerperium: an evaluation of methods for collecting urine specimens.

Five hundred and eighteen puerperal patients were screened for bacteriuria by examination of clean-catch, midstream urine specimens using the dip-slide cultivation technique. Bladder urine from 105 patients showing 10(4) or more bacteria per milliliter of midstrean urine was obtained by suprapubic bladder aspiration and cultivated, along with two consecutive midstream specimens. The bacteriologic results in these specimen categories are compared. Of 23 patients showing growth in the midstream samples compatible with a true bacteriuria, 18 had sterile puncture urine specimens. Consecutive contaminated midstream specimens from the same patient usually yielded growth of the same bacterial species. It is concluded that a diagnosis of bacteriuria in the puerperium cannot be based upon cultural results of midstream specimens alone. In several of the bladder urine specimens, microogranisms being nonpathogenic in the urinary tract and residing normally in the vaginal flora were found, probably due to the traumatic effect of partus. In Oslo the frequency of bacteriuria among women post partum is estimated at a maximum of 1 per cent.

Bacteriuria↗
PubMed1978

Treatment for premature ejaculation through male-only groups.

A report on the treatment of premature ejaculation in a group format is provided. In this format only males attended group therapy sessions, but they were expected to relay all information on the group meetings to their regular sexual partners. The women then participated in structured retraining exercises with their male partners. This approach was both cost effective and successful for most couples. It is argued, though, that group treatments are not likely to be as effective as the Masters and Johnson strategy and that clinics should, therfore, remain flexible enough to provide more individualized treatment for those couples who do not succeed with group approaches. Therapists are also encouraged to ensure that treatment gains are well established before terminating therapy.

Adult↗
PubMed1977

Role of transferrin in determining internal iron distribution.

The behavior in vivo of transferrin in loading and unloading iron from its two sites was examined in rats. Radioiron entering the plasma from the gastrointestinal tract in iron-deficient, normal and iron-loaded rats did not differ in its subsequent tissue distribution between erythroid marrow and liver of normal recipients from a second isotope added to the same plasma in vitro. Loading studies in vitro were then carried out employing a reticulocyte incubation model designed to place one isotope predominantly on one site of transferrin, more available to the erythron, and the second isotope on the other site, more available to the liver. In 15 groups of animals in which 3 different iron salts were employed to load transferrin with iron, the mean isotope ratio in the erythron was 1.03 (+/-0.06 SD) and the mean liver ratio was 0.75 (+/-0.21 SD). It was found that the incubation of plasma with reticulocytes resulted in contamination of the plasma by radioactive hemoglobin. After allowance was made for hepatic uptake of radiohemoglobin in the 13 groups in which proper correction could be made, the isotope ratio in the liver became 0.97 (+/-0.17 SD). It is concluded that iron atoms from the two sites of transferrin have similar tissue distributions in vivo in the experimental situations examined.

Animals↗
PubMed1976

Evaluation of family intervention through unobtrusive audio recordings: experiences in "bugging" children.

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.

Journal Article↗
PubMed1975

Multiple criteria follow-up of behavior modification with families.

This report presents termination and follow-up evaluations of a parent training program based on behavior modification principles. Treatment termination outcome data were obtained for 22 families, and follow-up data were collected on 14 of these families 3 and 8 months after treatment. Results indicated a fairly high level of success at termination on the basis of parent-collected observational data, parent attitude change toward the children, and parent attitude concerning the process and outcome of treatment. Modest levels of success were evidenced on the basis of behavioral data recorded by trained observers in the home. Families who participated in follow-up demonstrated greater cooperation and involvement with the treatment program than those who did not participate. In all other respects, however, these two groups were similar. Follow-up data on parent attitude measures demonstrated maintenance of the treatment effects. Parent observational data were incomplete, but also showed maintenance in follow-up. For the subsample of 14 cases, home observation records indicated a nonsignificant decline in deviant behavior at termination followed by a nonsignificant increase in deviant behavior during follow-up. The meaning and implications of these discrepant findings were discussed and compared with results from other laboratories.

Behavior Therapy↗
PubMed1975

Hormone and enzyme assays in pregnancy. V. A rapid method for measuring the placental cystine-aminopeptidase using 1-cystine-bis-1-cystine-bis-p-nitroanilide-nitroanilide as substrate.

A rapid and simple method for determination of the placental cystine-aminopeptidase (P-CAP) activity in plasma is presented. The enzyme-catalysed hydrolysis of the substrate, 1-cystine-bis-p-nitroanilide, is followed in a spectrophotometer by reading the absorbance of the product p-nitroaniline at 380 nm. The absorbance increases linearily with time after a lag-period of 30 seconds to 5 min. The reaction is followed for about 10 min and the increase in absorbtion per min is calculated from the linear part of the absorbtion curve. The test could also be performed by taking 2 readings at about 5 min intervals. In the studies of the enzyme kinetics a competitive inhibitor of the reaction was found in plasma. The amount of the inhibitory substances seemed to be nearly constant in the plasma samples studied from normal pregnant women as well as in plasma samples with high enzyme activity (twin-pregnancy) and low enzyme activity (severe pre-eclampsia). The normal enzyme activity pattern showed an increase from about 210 days of pregnancy and towards the term. A coefficient of correlation of plus 0.83 with the more time consuming method using 1-cystine-di-beta-naphtylamide as substrate was found. It was concluded that the present method could replace the method described by Babuna & Yenen (1966) at least from about 210 days of pregnancy and where a rapid answer is necessary.

Adult↗