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Biomedical subjects

J McKinney

Publications and source records attributed to J McKinney.

9 recordsLinked to original sources
PubMed1992

Is START a switch?

The cell cycle in Saccharomyces cerevisiae is controlled by regulation of START in late G1. The CLN1, CLN2 and CLN3 family of cyclin homologues is required for cells to pass START. They probably act by activating the CDC28 protein kinase. Expression of CLN1 or CLN3 under the control of an inducible promoter shows that transcription of either gene is sufficient for cyclin-deficient strains arrested in G1 to traverse START. A model of START regulation involves activation of CDC28 kinase by any CLN protein, leading to activation of CLN1 and CLN2 transcription in a positive feedback loop and passage through START. The cell cycle-dependent transcriptional regulators SWI4 and SWI6 may be components of the feedback loop. Cell cycle commitment entails resistance to the inhibitory action of mating factor, which correlates with peak levels of CLN1 and CLN2 mRNAs. FAR1 encodes an alpha-factor-dependent inhibitor of CLN function whose expression is markedly reduced at the time of START. The interplay of all these factors may sharpen the START transition such that it is close to an all-or-nothing switch event. This may be important for several START-dependent events to be activated at the same time, leading to coordinated cell cycle progression.

Cell Cycle↗
PubMed1992

Occupational therapists in private practice.

Although increasing numbers of occupational therapists are choosing to work in private practice, little data exist describing this sector of the profession. In the present study, experienced occupational therapists were asked about their moves into private practice, including (a) their motivation, (b) their preparation, and (c) their perceptions of the move's risks and benefits before and after the move. A survey was sent to a national random sample of 105 occupational therapists, 74 of whom responded. According to the survey, autonomy was the most important motivating factor for occupational therapists moving into private practice. However, once they were in private practice, the occupational therapists noted that increased income was a major benefit. These occupational therapists had planned for the risks of reimbursement, referral sources, and overhead but had not anticipated problems with staffing shortages. Incomes increased for occupational therapists who moved into private practice. The survey compared the incomes of occupational therapists before and after they entered private practice. It also compared their income and educational levels. Other comparisons included income and work experience, income and work role, and income and geographic location. Autonomy and financial considerations appear to be the overriding issues for occupational therapists choosing careers in private practice. Almost unanimously, the survey respondents said that private practice was a good career choice.

Adult↗
PubMed1991

Disabling cerebral transient ischemic attacks.

The surgical management of an emerging clinical entity, namely disabling transient cerebral ischemic attacks, is described. A series of 19 patients treated in a 2-year period (12 with anterior circulation dysfunction and seven with posterior insufficiency) met the following criteria: 1) stereotypical recurrent episodes of transient neurological dysfunction related to the anterior or posterior circulation distribution; 2) failure of maximum medical therapy to control the transient neurological dysfunction; 3) four-vessel cerebral angiography demonstrating an isolated vascular territory corresponding to patient symptoms; 4) inhalation xenon cerebral blood flow studies with at least three of eight probe-pairs showing significant asymmetries in the initial slope index, localizing an area of relative oligemia to the symptomatic hemisphere (anterior circulation only); and 5) severe restriction of lifestyle due to transient ischemic attacks (TIA's). Seventeen patients underwent surgical bypass therapy: deep sylvian superficial temporal artery (STA)-middle cerebral artery (MCA) bypass in nine; surface STA-MCA bypass in three; STA-superior cerebellar artery bypass in three; STA-posterior cerebral artery bypass in one; and aorta-carotid artery bypass in one. There was one perioperative death and four perioperative strokes (two ipsilateral and two contralateral to the operated side). The average follow-up period was 14 months. Of the 16 surviving surgically treated patients, 13 (81%) have had an excellent to good outcome with complete resolution of TIA's and minimal neurological deficits. Three patients had a poor outcome with either a significant persistent neurological deficit or continued TIA's. The two patients not treated surgically continue to have vertebrobasilar insufficiency episodes while receiving oral anticoagulation medication. The overall mortality rate (5.5%) and stroke morbidity rate (22.2%) of surgical therapy for disabling TIA's are high in this neurologically unstable group of patients, but are associated with an 81% excellent to good response. Although the natural history of disabling TIA's is not known, these patients present with significant to total disability due to their symptoms. It is concluded that disabling TIA's respond to surgical revascularization and may represent an indication for cerebral revascularization surgery.

Cerebral Revascularization↗
PubMed1991

Implementation of a local area network for nursing management.

This paper describes the planning and implementation of a Local Area Network (LAN) for the nursing service of a 504-bed urban teaching hospital. The major goals of the network were: support for nurse executives, nurse managers, and the departmental assistants assigned to administrative offices; increased efficiency and effectiveness of the nursing administrative areas; and improved communication systems. Collaboration between the nursing service and the Computer Information Center (CIC) resulted in a network of over 70 workstations, spanning 11 buildings. The network provides access to multiple programs that support clinical, managerial, and research activities. Gateways provide access to the hospital's two mainframes.

Boston↗
PubMed1990

Comparison between the counter-rotational toothbrush and multi-action toothbrush.

Previous studies have demonstrated that two types of powered toothbrushes (Interplak and Braun) are more effective than a manual toothbrush in the removal of bacterial plaque from tooth surfaces. The purpose of this study was to compare the effectiveness of the Interplak Home Plaque Removal Instrument (A) and the Braun Electric Toothbrush (B) on supragingival plaque removal and gingival bleeding following (1) one time instruction; (2) reinstruction and one week of home use; (3) a third instruction and three weeks of home use. The sample population for this study consisted of twelve subjects: six (6) were randomly assigned to use the Interplak, and the remaining six (6) were assigned to use the Braun. Subjects met specific qualification criteria to participate in this examiner-blind study. The Turesky Modification of the Quigley-Hein Plaque Index and an Objective-Subjective Gingival Abrasion Index were scored before and after brushing at the initial appointment, one week later, and at the final appointment in three weeks. A timed bleeding index (Barnett-Muhleman) and probing depths were recorded at the beginning of all three appointments. Subjects received instructions on the use of the assigned toothbrush in a clinical demonstration and in a printed format to take home. Subjects were then supervised in their brushing technique. Data was analyzed using a Wilcoxon Signed Rank Test and Analysis of Variance with Repeated Measures where appropriate. Although the number of patients was small, a statistically significant difference (p less than .05) in plaque scores between the groups was obtained in favor of the Interplak.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Histone H1 subtype-specific consensus elements mediate cell cycle-regulated transcription in vitro.

In this study we used nuclear extracts from centrifugally elutriated cell populations to study histone H1 transcriptional regulation during the cell cycle. Analysis of mutations within the H1 promoter establish that both of the H1 subtype-specific consensus elements participate in induction of transcription upon entry into S phase. The DNA binding activity of H1TF2, which specifically interacts with the H1 proximal subtype-specific element, is increased in S-phase nuclear extracts, whereas no increase in DNA binding is observed for the H1 distal subtype-specific DNA transcription factor H1TF1 or the H2b subtype-specific factor OTF1. These data strongly support the idea that histone gene subtype-specific transcription factors are important for S-phase-dependent expression of histone genes. Further studies of these factors will be important for increased understanding of the transition from G1 to S phase of the mammalian cell cycle.

Animals↗
PubMed1988

An evaluation of labeling-then-doing with moderately handicapped persons: acquisition and generalization with complex tasks.

We conducted two experiments in which moderately mentally retarded persons were trained first to label and then to enter characters into a computer, calculator, or checkbook (label-then-do) within a multiple baseline design. In Experiment 1, 5 young adults were trained to enter statistical programs into computers in an office setting. Following training, all subjects' use of verbal labels and key-entry skills generalized across tasks (programs) and settings (offices and computer terminals). In Experiment 2, 3 junior high school students were trained with self-labeling procedures to complete a key-entry task and to balance a checkbook. The performance of all students generalized across tasks and settings, and the use of labels generalized for 2 of the students. Results are discussed relative to mediated generalization and to establishing verbal control over behavior.

Adolescent↗
PubMed1987

Polychlorinated biphenyls and related compound interactions with specific binding sites for thyroxine in rat liver nuclear extracts.

Thyroid hormone analogues, polychlorinated biphenyls (PCBs), and their derivatives were shown to bind specifically to thyroxine-specific binding sites in rat liver nuclear extracts. The structure-binding relationship for thyroxine binding prealbumin was qualitatively similar to that for the nuclear receptor. In general for both binding proteins, increased binding affinity was seen for the more linear and in some cases rectangular shaped (as opposed to the angular shaped thyroid hormones) chlorinated aromatic hydrocarbons with chlorine concentrated in lateral positions (3,3',5,5'-substitution on biphenyl nucleus). However two groups of compounds showed distinct quantitative differences. The relatively less polar and more lipophilic nonhydroxylated PCBs bound the nuclear receptor with significantly lower affinities while two compounds that are structurally related by the potential for equilibrium interconversion to a rigid planar structure bound with significantly higher affinities. This latter class of compounds represents soluble dioxin (TCDD) approximate isosteres and has an extended (polarizable) pi-system brought about by a planar structure (or conversion to the same) and lateral halogenation. These structure requirements are maximally expressed in 3,3',5,5'-tetrachlorodiphenoquinone (TCDQ), which shows a remarkably high affinity (Ka = 1.84 X 10(11) M-1) for the nuclear receptor. Thus, the nuclear receptor shows the expected structural specificity and sensitivity for possible involvement in the high toxicity of these classes of compounds. The physiological significance of these binding results is supported by the dose-dependent regulation (increase) of the thyroxine nuclear receptor number by dioxin, although the mechanism responsible for this increase is not clear. The nuclear binding component was further analyzed by sucrose density gradient centrifugation and was found to have a sedimentation coefficient of 4.3 S under high salt conditions. A crude estimate of the molecular weight (45,200) was obtained from a linear plot of standard globular protein fraction number (sedimentation coefficient) vs. log molecular weight. Although direct evidence is not provided, the thyroxine nuclear receptor may cooperate with a second receptor in binding the TCDQ type ligand or exists as a multimeric species with binding properties of both prealbumin and the dioxin (or Ah) receptor.

Animals↗