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Biomedical subjects

M Barrett

Publications and source records attributed to M Barrett.

At least 55 records · Page 3Linked to original sources
PubMed1988

Quality assurance review: improving diagnostic accuracy of percutaneous needle biopsy.

Adequate pathologic slide preparation of percutaneous fine-needle biopsy (PFNB) specimens is necessary to maximize sensitivity and yield a tissue diagnosis. We present a quality control review of our biopsy technique and results in 71 aspiration biopsies done in 59 patients. Immediate cytology slide preparation in the radiology suite enabled us to increase our diagnostic yield from 53% to 84%, and allowed us to preserve PFNB, rather than open biopsy, as the primary diagnostic modality. We recommend regular review of biopsy techniques to confirm adequate diagnostic yields of these procedures.

Biopsy, Needle↗
PubMed1987

Use of the maximal-operant principle to motivate children's intrinsic interest.

The present research examined the hypothesis that in contrast to theory and research indicating that tangible reward decreases subsequent interest in enjoyable academic activities, rewards are perceived by adults as effective techniques to maximize long- and short-term subsequent interest for academic tasks of both high and low initial interest level. The results of our first three studies demonstrated that college students and parents view tangible reward as more effective than other less controlling techniques to enhance intrinsic motivation and value rewards more for intrinsically interesting academic behaviors in comparison with others (e.g., prosocial behaviors). Our fourth study supported the hypothesis that adults do not subscribe to the minimal-sufficiency analysis of increasing intrinsic motivation but prefer a maximal-operant principle in which the likelihood of producing long-term interest in academic tasks is assumed to vary positively with the size of a reward. Our fifth and sixth studies investigated illusory correlation as one mechanism that may perpetuate beliefs about the assumed positive relation between tangible reward and intrinsic interest in academic tasks.

Achievement↗
PubMed1987

Needle biopsy evaluation of class II major histocompatibility complex antigen expression for the differential diagnosis of cyclosporine nephrotoxicity from kidney graft rejection.

Twenty needle biopsies from 14 patients were taken at times of renal dysfunction, and frozen sections were stained for class I and class II major histocompatibility complex (MHC) antigen expression using the immunoperoxidase technique and monomorphic mouse monoclonal antibodies. Eight of the 9 biopsies taken during periods of dysfunction attributed to cyclosporine toxicity had normal levels of class II expression. In contrast, 9 of the 10 biopsies taken during episodes of rejection had easily recognized increases in class II expression. In the one case where no definite clinical diagnosis was possible, no class II induction was present. Class I levels were less definitive but tended to be markedly raised in the cases of rejection, and only mildly raised in the cases of nephrotoxicity. Biopsy results can be available within 1 1/2-2 hr. The test is therefore likely to be of value in the correct diagnosis of the cause of renal dysfunction and thereby improve the management of cyclosporine-treated renal transplant patients.

Antibodies, Monoclonal↗
PubMed1987

The clinical value of acute phase reactant measurements in thermal injury.

Acute phase reactants (APRs) have been usefully used to monitor the patient's progress in a number of non-burn situations and there have been occasional reports hinting at their possible role in burns. In this study several APRs have been measured in burned patients. There is some limited value in measuring the APRs, particularly CRP, in thermally injured patients. However, interpretation of the results is difficult.

Acute-Phase Proteins↗
PubMed1987

Neuropsychological studies on adolescents with phenylketonuria returned to phenylalanine-restricted diets.

Nine adolescents with phenylketonuria (PKU), who had been on unrestricted diets for 2 to 11 years, underwent serial neuropsychological testing over two consecutive 4- to 5-week periods during which each was maintained on a low-phe diet supplemented in a triple-blind fashion either with L-phe (high phe) or L-alanine (low phe). Assignment to the initial condition was done randomly, and the alternate condition was substituted at the end of the first 4- to 5-week period. In 6 of 7 subjects with PKU, baseline median choice reaction times (RTs) were slower than those of controls matched for age, sex, handedness, and Full-Scale IQ (WISC-R). A highly significant improvement occurred during the low-phe phases of the study. Results suggest that adolescents with PKU on unrestricted diets have a neuropsychological deficit that is out of proportion to their overall intellectual handicap. Moreover, this deficit appears to be at least partly reversible by return to dietary phe restriction despite years of hyperphenylalaninemia.

Adolescent↗
PubMed1985

Performance and motivational deficits of helplessness: the role of motivational orientations.

The present study examined the hypothesis that the effect of failure feedback in producing learned helplessness would depend on the motivational orientation of a child. Extrinsically motivated children were predicted to exhibit performance decrement following a failure experience, whereas the opposite was predicted for intrinsically motivated children. In addition, success feedback was predicted to enhance subsequent performance only for the intrinsic group. Following success, failure, or no feedback on an activity reflecting spatial skills (an incomplete picture task), subjects' performance on an activity tapping different skills (i.e., anagrams) provided by a second experimenter served as the primary measure of helplessness. Subjects' intrinsic motivation in performing the incomplete picture task, a similar task (embedded figures) and a dissimilar task (dots-to-dots) was also examined. The results supported the predictions on both performance and intrinsic motivation measures. The results are discussed in terms of implications for learned helplessness as well as cognitive evaluation theories.

Achievement↗
PubMed1985

Primary nursing. Teamwork is the answer.

Eight years of experience with primary nursing in a 750-bed acute care teaching hospital revealed several persistent problems: isolationism among nurses, communication problems between nurses and physicians, inadequate documentation, and insufficient time for patient and staff education, resulting in frustration for the nursing staff. By combining the basic elements of primary and team nursing, a 3-month pilot in one unit resulted in improved job satisfaction for professional staff, improved quality assurance scores, and increased physician-nurse communication.

Documentation↗
PubMed1984

Bacterial meningitis in Johannesburg--1980-1982.

A 2-year retrospective study of aetiology, age distribution, seasonal variation and antimicrobial sensitivity patterns of bacteria isolated from patients with meningitis in five Johannesburg hospitals for White, Black, Coloured and Asian patients was performed. Neisseria meningitidis was isolated most frequently, followed by Streptococcus pneumoniae, Haemophilus influenzae, Escherichia coli and Streptococcus group B. In the Black population 73% of the meningococcal infections occurred in patients over 3 years of age, and the majority of these infections were caused by serogroup A organisms. Virtually all (93%) of the H. influenzae infections occurred in children of less than 3 years of age. Of the isolates tested, 16% of the meningococci, 4,5% of the H. influenzae and 47% of the pneumococci were resistant to sulphadiazine, ampicillin and penicillin respectively.

Adolescent↗
PubMed1982

Hydration and percutaneous absorption III: Influences of stripping and scalding on hydration alteration of the permeability of hairless mouse skin to water and n-alkanols.

The influence of hydration on the permeability of stripped and scalded skins of hairless mice was investigated in vitro using water and n-alkanols as test permeants. Irrespective of pretreatment, the permeation rates of water, methanol, and ethanol were unaffected by aqueous immersion of skin sections in a diffusion cell, consistent with earlier data on unprocessed skins. The permeation rates of butanol and hexanol also were insensitive to hydration, differing from earlier studies on normal, intact skin in which both solutes' rates doubled after 10 hr of soaking. Following both pretreatments, the permeability of octanol declined over the first 5-10 hr of maceration, but remained invariant thereafter. The decline was most pronounced for the scalded skins. With untreated skin, octanol permeability initially increased and then declined before assuming a constant value. This study indicates that the barrier properties of the epidermis and dermis are not particularly sensitive to extended hydration except in the case of octanol. Scalding at 60 degrees for 60 sec rapidly hydrates the skin, altering tissue permeability to about the same extent as a 10-hr (or longer) immersion in water at 37 degrees. Octanol's unique hydration profile is explained by locating the origin of permeability decline in tissue beneath the horny exterior of the skin.

Abdomen↗
PubMed1981

Hydration and percutaneous absorption II: Influence of hydration on water and alkanol permeation through Swiss mouse skin; comparison with hairless mouse.

In vitro permeation studies with biological membranes often involve long, aqueous maceration of the tissue. The present investigation examined the possible effects of hydration on barrier integrity of Swiss mouse skin; using water, methanol, ethanol, and butanol as permeants and a previously developed procedure involving multiple, sequential permeation runs on each piece of skin. The permeation rate of water increased almost linearly up to 30 hr of hydration and then tended to level off. Transport rates of methanol and ethanol increased asymptotically and then plateaued at approximately 15 hr. These results contrast with earlier findings on hairless mouse skin where the permeabilities of these three compounds were unaffected by aqueous immersion. The permeation rate of butanol also increased during the first 15 hr of hydration but gradually declined over the next 25 hr. This result again contrasts with the hairless mouse species in which butanol permeability doubled in 10 hr and then plateaued. The species differences in the hydration profiles appear related to the vastly dissimilar pellages and, in the Swiss mouse, may indicate greater involvement of the transfollicular pathway.

Alcohols↗
PubMed1980

Trypanosoma murmanensis: its effects on the longhorn sculpin, Myoxocephalus octodecemspinosus.

A study was undertaken to ascertain the effects of Trypanosoma murmanensis, on adult longhorn sculpins (Myoxocephalus octodecemspinosus) following experimental infection. Blood samples, taken at intervals after infection, indicated a decrease in hematocrit, hemoglobin and total plasma protein levels which did not return to normal for at least 72 days. An increase of lymphocytic cells occurred about 42 and 58 days but reverted later to normal levels. Anemia persisted despite low parasitemias and might be attributed to lytic factors released directly or indirectly by the parasite and/or an inability of the erythropoietic system to respond following the initial blood loss.

Anemia↗