PubMed Health⌕ Search

Biomedical subjects

J Pfeffer

Publications and source records attributed to J Pfeffer.

34 records · Page 2Linked to original sources
PubMed1983

Comparison of mothers' and fathers' temperament ratings of referred and nonreferred preschool children.

Examined the ratings of mothers and fathers of two groups of preschool children on the Parent Temperament Questionnaire-Revised. One group of preschoolers had been referred for psychological evaluation by parents because they were difficult to manage at home or at school (N = 48); the other group (N = 48) never had been referred for psychological services. The referred and nonreferred groups were found to differ significantly in ratings of six temperament variables. Mothers' and fathers' ratings for the nonreferred group were significantly correlated, while for the referred group they were generally not significantly correlated.

Child Behavior Disorders↗
PubMed1983

Synaptic plasticity in the cerebral cortex of mice: effects of radiation and anesthesia.

In the neuropil of layers II and III of the frontal cortex of adult mice, as seen in the electron microscope, sodium pentobarbital anesthesia alone results in a significant decrease in synaptic profile length at 1 day after anesthetization, followed by a return to normal or above normal levels after 2-28 days, while the number of synaptic profiles per unit cross section (profile incidence) is not altered; irradiation with 5-500 rad plateau argon particles significantly inhibits the profile shortening effect of anesthesia at 1 day after exposure, but this inhibition is not dose related; an inverse dose relationship in profile incidence appears at 2 days following irradiation with argon particles; at 1 to 2 hours after 150 or 220 rad x-irradiation, profile incidence is significantly reduced while the length is increased, effects that appear to be dose related and unaffected by adrenalectomy.

Animals↗
PubMed1978

A social information processing approach to job attitudes and task design.

This article outlines a social information processing approach to explain job attitudes. In comparison with need-satisfaction and expectancy models to job attitudes and motivation, the social information processing perspective emphasizes the effects of context and the consequences of past choices, rather than individual predispositions and rational decision-making processes. When an individual develops statements about attitude or needs, he or she uses social information--information about past behavior and about what others think. The process of attributing attitudes or needs from behavior is itself affected by commitment processes, by the saliency and relevance of information, and by the need to develop socially acceptable and legitimate rationalizations for actions. Both attitudes and need statements, as well as characterizations of jobs, are affected by informational social influence. The implications of the social information processing perspective for organization development efforts and programs of job redesign are discussed.

Attitude↗
PubMedDate not supplied

Ultrasound thrombolysis in hemodialysis access: in vitro investigation.

PURPOSE: To evaluate the effectiveness of ultrasound thrombolysis in occluded hemodialysis access shunts using an in vitro model. METHODS: Thrombosed hemodialysis accesses were simulated by clotted bovine blood in a flow model (silicone tubing; inner diameters 4, 6, and 9 mm). After retrograde and antegrade sheath placement (7 Fr), mechanical thrombolysis was performed using an ultrasound probe (Acolysis, Angiosonics, Morrisville, NC, USA). The tip of the device measured 2.2 mm in diameter. During sonication, the catheter was moved slowly back and forth using an over-the-wire system. Thirty complete occlusions [tubing diameters 4 mm (n = 12), 6 mm (n = 12), 9 mm (n = 6)] were treated. Initial thrombus weights were 3.5 (+/- 0.76) g, 7.7 (+/- 1.74) g, and 19.4 (+/- 2.27) g for the three diameters. Maximum sonication time was 15 min for each probe. RESULTS: With this device, we were able to restore a continuous lumen in all 12 occluded 4 approximately mm silicone tubes. No wall-adherent thrombi remained after sonication for 3.5--9.6 min. In hemodialysis access models with diameters of 6 mm, thrombus fragments persisted in 25% (3/12 accesses). These were located in the medial portion of the access loop and near to the puncture sites. However, flow was re-established after 5.0--13.0 min of treatment in all settings. Mechanical dissolution of thrombus material failed in five of six access models with diameters of 9 mm, even though ultrasound energy was applied for the maximum of 15 min. CONCLUSION: In a clotted hemodialysis shunt model, successful ultrasound thrombolysis was limited to small access diameters and small amounts of thrombus.

Equipment Design↗
PubMedDate not supplied

The isolated perfused liver. a new model using autologous blood and porcine slaughterhouse organs.

INTRODUCTION: Current models of isolated and perfused livers are limited by nonphysiologic perfusates or the need for the use of high numbers of laboratory animals. The present study was performed in order to rectify these difficulties. METHODS: To establish a new isolated perfused liver model, a perfusion circuit was developed using normothermic, autologous hemoperfusion and organs obtained from a slaughterhouse. RESULTS: Stable organ function was maintained over 220 min. The organs displayed physiologic values for measured variables, including oxygen consumption which varied from 5.2+/-1.5 ml/min at 40 min to 5.2+/-2.4 ml/min at 220 min, and bile production (0.15-0.31 ml/min, respectively). DISCUSSION: The present studies demonstrate a new approach for experimental liver perfusion by combining the optimal perfusion medium of autologous blood and slaughterhouse organs as source material.

Alanine Transaminase↗
PubMedDate not supplied

Hypertension.

Explore the source record for details and available documents.

Cardiomegaly↗
PubMedDate not supplied

Cardiac hypertrophy and performance of Dahl hypertensive rats on graded salt diets.

The relationship between arterial pressure and left ventricular (LV) functional capacity and LV mass during the natural development of cardiac hypertrophy was assessed in Dahl-resistant (R) and -sensitive (S) hypertensive rats maintained on three dietary NaCl regimens (0.4%, 4.0%, and 8.0% for 9 weeks, then 4.0%) from 5 until 20 weeks of age. In R rats, arterial pressure and LV mass were unaffected by diet. In contrast, S rats demonstrated levels of arterial pressure and LV hypertrophy that were graded according to dietary NaCl. Hemodynamic studies on rats under ether anesthesia demonstrated that the graded pressure elevation in S rats was produced by corresponding increases in total peripheral resistance, as cardiac output did not vary. During acute volume loading, the S rats on all diets achieved the same maximum stroke volume as did R rats, despite the marked increase in the arterial pressure of S rats. An analysis of the ejection fraction/afterload relationship demonstrated preserved contractile state. The ability of the left ventricle to generate pressure was increased in S rats in direct proportion to the degree of LV hypertrophy. Thus, in young adult S rats, cardiac performance was well compensated since pump and contractile functions were maintained and pressure-generating capacity was increased in relation to the degree of LV hypertrophy.

Animals↗
PubMedDate not supplied

Six dangerous myths about pay.

Every day, executives make decisions about pay, and they do so in a landscape that's shifting. As more and more companies base less of their compensation on straight salary and look to other financial options, managers are bombarded with advice about the best approaches to take. Unfortunately, much of that advice is wrong. Indeed, much of the conventional wisdom and public discussion about pay today is misleading, incorrect, or both. The result is that business people are adopting wrongheaded notions about how to pay people and why. In particular, they are subscribing to six dangerous myths about pay. Myth #1: labor rates are the same as labor costs. Myth #2: cutting labor rates will lower labor costs. Myth #3: labor costs represent a large portion of a company's total costs. Myth #4: keeping labor costs low creates a potent and sustainable competitive edge. Myth #5: individual incentive pay improves performance. Myth #6: people work primarily for the money. The author explains why these myths are so pervasive, shows where they go wrong, and suggests how leaders might think more productively about compensation. With increasing frequency, the author says, he sees managers harming their organizations by buying into--and acting on--these myths. Those that do, he warns, are probably doomed to endless tinkering with pay that at the end of the day will accomplish little but cost a lot.

Commerce↗
PubMedDate not supplied

The smart-talk trap.

In today's business world, there's no shortage of know-how. When companies get into trouble, their executives have vast resources at their disposal: their own experiences, colleagues' ideas, reams of computer-generated data, thousands of publications, and consultants armed with the latest managerial concepts and tools. But all too often, even with all that knowledge floating around, companies are plagued with an inertia that comes from knowing too much and doing too little--a phenomenon the authors call the knowing-doing gap. The gap often can be traced to a basic human propensity: the willingness to let talk substitute for action. When confronted with a problem, people act as though discussing it, formulating decisions, and hashing out plans for action are the same as actually fixing it. And after researching organizations of all shapes and sizes, the authors concluded that a particular kind of talk is an especially insidious inhibitor of action: "smart talk." People who can engage in such talk generally sound confident and articulate; they can spout facts and may even have interesting ideas. But such people often exhibit the less benign aspects of smart talk as well: They focus on the negative, and they favor unnecessarily complex or abstract language. The former lapses into criticism for criticism's sake; the latter confuses people. Both tendencies can stop action in its tracks. How can you shut the smart-talk trap and close the knowing-doing gap? The authors lay out five methods that successful companies employ in order to translate the right kind of talk into intelligent action.

Administrative Personnel↗
PubMedDate not supplied

Seven practices of successful organizations. Part 2: Invest in training, reduce status differences, don't keep secrets.

The economic benefits to those firms that really put their people first can be enormous--particularly in industries that are as dependent on people as health care. Extensive research shows that seven specific practices are related to such enhanced organizational performance. In part 1 of this article (in the January/February 1999 issue of this journal), I described four of these practices: employment security, selective hiring, self-managed teams and high compensation. Here, I discuss the remaining three: training, reduction of status differences and sharing information. Knowing what should be done and what it can accomplish should spur you and your colleagues to explore ways of actually implementing this knowledge.

Communication↗
PubMedDate not supplied

Fragmentation of pulmonary emboli: in vivo experimental evaluation of two high-speed rotating catheters.

PURPOSE: To test two over-the-wire systems for fragmentation of pulmonary emboli. METHODS: In 11 dogs, 22 embolic occlusions of lobar or central pulmonary arteries were performed by injection of preformed emboli through a jugular vein sheath. A commercially available device (thrombolizer) and a modified version of the impeller catheter were introduced via the femoral vein and positioned at the embolus site. RESULTS: Catheter placement at the site of the emboli was possible. In more than half of the cases a hydrophilic or an extra-stiff guidewire was necessary. The thrombolizer did not rotate properly with its original pneumatic drive and required a major modification. When sufficient rotation was provided, both fragmentation catheters were able to clear the occluded main arteries. Side branches were partly obstructed by the resulting fragments. Recanalization led to a reduction of the emboli-induced elevation of the pulmonary arterial pressure by two-thirds. Histology of the recanalized pulmonary artery segments revealed localized (impeller catheter) and widespread (thrombolizer) periarterial hemorrhage. CONCLUSION: Embolus fragmentation led to a hemodynamic improvement. The impeller catheter was less traumatic compared with the thrombolizer, which was technically insufficient.

Animals↗
PubMedDate not supplied

[Seasonal variation in sperm characteristics].

In all species, seasonal patterns in fertility are observed. In humans, seasonal variations of pregnancies are observed in spontaneous reproduction or in IVF. The most important factor seems to be sperm values and specially the morphology. Our study, on 188,075 cases (FIVNAT 1987-1995) shows significant variations of semen characteristics: we observe, in August, an improvement of sperm morphology.

Female↗