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Biomedical subjects

K Chapman

Publications and source records attributed to K Chapman.

At least 109 records · Page 6Linked to original sources
PubMedDate not supplied

Instruments for the screening of speech/language development in children.

This article discusses issues relevant to the use of an instrument that screens speech and language development and reviews instruments that are currently available for screening general speech and language development in children age birth through 8 years. Five instruments for the assessment of general speech and language development are reviewed. Each of these instruments has strengths, but none completely meets the requirements of psychometric soundness and practicality for use in most ambulatory pediatric settings. Each practitioner should consider the strengths and limitations associated with each instrument, as well as the needs and characteristics of the population who will be screened to make an informed decision about the most appropriate instrument(s) for use in their practice.

Child↗
PubMedDate not supplied

Identification and quantitation of benzo[a]pyrene-DNA adducts formed in mouse skin.

The DNA adducts of benzo[a]pyrene (BP) formed in vitro were previously identified and quantitated. In this paper, we report the identification and quantitation of the depurination adducts of BP, 8-(benzo[a]pyren-6-yl)guanine (BP-6-C8Gua), BP-6-N7Gua, and BP-6-N7Ade, formed in mouse skin by one-electron oxidation, as well as the major stable adduct formed via the diolepoxide pathway, BP diolepoxide bound at C-10 to the 2-amino of dG (BPDE-10-N2dG). Identification of the depurination adducts was achieved by HPLC and fluorescence line narrowing spectroscopy. The depurination adducts, BP-6-C8Gua (34%), BP-6-N7Gua (10%), and BP-6-N7Ade (30%), constituted 74% of the adducts found in mouse skin 4 h after treatment with BP. The stable adduct BPDE-10-N2dG accounted for 22% of the adducts. Treatment of the skin with BP-7,8-dihydrodiol or BP diolepoxide yielded almost exclusively the stable adduct BPDE-10-N2dG. When BP or BP-7,8-dihydrodiol was bound to RNA or denatured DNA in reactions catalyzed by rat liver microsomes, no depurination adducts were detected. The profiles of stable adducts were similar both qualitatively and quantitatively with native or denatured DNA. With activation of BP by horseradish peroxidase, the profiles of stable adducts differed with native and denatured DNA. The total amount of adducts with denatured DNA was only 25% of the amount detected with native DNA. No depurination adducts were detected with denatured DNA or RNA in the peroxidase system.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Topical↗
PubMedDate not supplied

Assembly of microtubules at the tip of growing axons.

The growth of axons in the developing nervous system depends on the elongation of the microtubules that form their principal longitudinal structural element. It is not known whether individual microtubules in the axon elongate at their proximal ends, close to the cell body, and then move forward into the lengthening axon, or whether tubulin subunits are transported to the tip of the axon and assembled there onto the free ends of microtubules. The former possibility is supported by studies of slow axonal transport in mature nerves from which it has been deduced that microtubule assembly occurs principally at the neuronal cell body. By contrast, the polarity of microtubules in axons, which have their 'plus' or 'fast-growing' ends distal to the cell body, suggests that assembly occurs at the growing tip, or growth cone, of the axon. We have addressed this question by topically applying Colcemid (N-desacetyl-N-methylcolchicine), and other drugs which alter microtubule stability, to different regions of isolated nerve cells growing in tissue culture. We find that the sensitivity to these drugs is greatest at the growth cone by at least two orders of magnitude, suggesting that this is a major site of microtubule assembly during axonal growth.

Alkaloids↗
PubMedDate not supplied

Preoperative HIV antibody testing: the views of surgeons and patients.

Fifty surgeons and 72 preoperative patients in 2 central London hospitals were asked their views on preoperative HIV antibody testing, who is at risk of HIV infection and HIV test counseling. A substantial proportion of both surgeons and preoperative patients, 48% and 54% respectively, supported compulsory HIV antibody testing without patient consent. They believed this should occur as a routine practice prior to surgery. However, surgeons and patients differed in the preoperative patients to be considered for such testing. All surgeons advocating compulsory testing believed that it was only necessary for those patients belonging to high risk groups whilst preoperative patients believed that all patients should be HIV tested prior to surgery. Surgeons and patients also differed in their views on who was at risk of HIV infection. Surgeons believed those at risk to be members of identifiable risk groups whilst patients believed everyone was at risk, especially those engaging in high risk behaviours. Finally, when asked which health professionals they thought should be involved in HIV test counselling, both surgeons and patients agreed that hospital doctors, including surgeons themselves, should take on the responsibility of test counselling. The implications of this and routine HIV antibody testing are discussed.

AIDS Serodiagnosis↗