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Biomedical subjects

D Gingrich

Publications and source records attributed to D Gingrich.

14 recordsLinked to original sources
PubMed1999

Recruiting and selecting generalist-oriented students at Pennsylvania State University College of Medicine.

The authors describe the strategies developed at the Pennsylvania State University College of Medicine, as part of The Robert Wood Johnson Foundation's Generalist Physician Initiative, to increase the proportion of graduating medical students entering generalist disciplines. These strategies included modifying the admission process to involve more primary care faculty so that students with identified potential for primary care would make up at least half of each entering class, and partnering with selected colleges and universities in Pennsylvania to increase the number of applicants with the potential for primary care. They describe partnering and outreach programs--Primary Care Day, off-campus cluster meetings, and the Primary Care Scholars Program for college seniors--and present promising information about the results.

Education, Medical, Undergraduate↗
PubMed1997

Excess coffee consumption in simulated complex work settings: detriment or facilitation of performance?

Twenty-four managers who normally consume between 400 and 1,000 mg of caffeine per day participated in all-day quasi-experimental simulations. In a crossover, doubleblind design, they made complex managerial decisions either on treatment with their typical daily dose of caffeine or on treatment with 400 mg of caffeine in excess of daily consumption. The effect of caffeine treatment on various validated performance indicators was investigated. The impact of excess caffeine consumption was mild. Increased caffeine facilitated speed of response to incoming information but decreased utilization of opportunity. No significance was obtained for other measures of managerial effectiveness (such as activity, breadth, strategy, and emergency response).

Adult↗
PubMed1995

Effects of caffeine deprivation on complex human functioning.

Twenty-five managers who reported an average daily caffeine consumption of 575 mg participated in two complex simulations. A double-blind cross-over design was employed to assess the effects of normal caffeine consumption versus caffeine deprivation upon seven validated measures of managerial effectiveness. Data from a Caffeine Withdrawal Questionnaire indicated discomfort upon deprivation. Systolic blood pressure increased during "normal" caffeine consumption levels but fell quickly and remained lower during deprivation. Several measures of managerial performance indicated decreased effectiveness upon caffeine deprivation. In contrast to prior research from simpler task settings, cognitive effectiveness (during complex task performance) was diminished. However, a measure of strategic performance which requires a relatively high level of cognitive effort showed no impact of caffeine deprivation.

Adult↗
PubMed1995

Alcohol hangover and managerial effectiveness.

Twenty-one male managers who normally drink moderate amounts of alcohol participated in a placebo-controlled, double-blind, cross-over experiment. Subjects consumed either placebo or alcoholic drinks to attain a breath alcohol level of 0.10 during the evening before participation in Strategic Management Simulations. By the time of arrival at the simultaion laboratory on the following morning, breath alcohol levels were measured at 0.00. Questionnaire responses indicated considerable hangover discomfort. Responses to semantic differential evaluative scales suggested that research participants evaluated their own managerial performance in the simulation setting as impaired. However, multiple (validated) measures of decision-making performance obtained in the simulation task did not show any deterioration of functioning. Previous research had shown considerable performance decrements in the same task setting, while blood/breath alcohol levels ranged from 0.05 through 0.10%. Apparently, complex decision-making competence by persons who normally consume moderate amounts of alcohol may not be impaired by hangover caused by intoxication during the previous evening that remains at or below a blood alcohol level of 0.10.

Adult↗
PubMed1994

Alcohol and managerial performance.

Effects of alcohol intoxication at .05 and .10 breath alcohol concentration upon a number of validated indicators of managerial performance were investigated in a double-blind crossover placebo-controlled simulation design. Managers (N = 48) spent 2 days handling quasi-experimental (partially event-controlled) tasks that permitted realistic managerial decision making under both "normal" and "emergency" conditions. The data showed that speed and frequency of managerial action were affected by alcohol at the .10 but not the .05 level. Strategy and planning deteriorated at both levels. Limited improvement of performance was observed for one simpler component of managerial functioning at the lower intoxication level, possibly due to myopia and/or a motivated "strain" toward better performance induced by the perception of impairment.

Adult↗
PubMed1992

Effects of alcohol intoxication on risk taking, strategy, and error rate in visuomotor performance.

Adult men (N = 44) participated for 2 days (alcohol vs. placebo treatment) in a double-blind, crossover experiment. Performance on the Digit Symbol Substitution Task (DSST) and a visuomotor (VM) task was measured 4 times each day. On the alcohol-treatment day, data were obtained once during ascending breath alcohol levels (BALs), once during maximal BALs (0.05 or 0.10), and twice during descending BALs. Data were collected at the same time points on the placebo-treatment day. Limited evidence for acute tolerance was obtained with the DSST, but error rates on the VM task were higher during maximal and descending BALs. Error rates remained near placebo values, and participants displayed slightly greater caution, while BALs were ascending. Strategy scores on the VM task exceeded placebo scores during maximal intoxication. Data interpretation is focused on individuals in higher level (e.g., professional) positions.

Adult↗
PubMed1991

Linkage between cooperative oxygenation and subunit assembly of cobaltous human hemoglobin.

The thermodynamic linkage between cooperative oxygenation and dimer-tetramer subunit assembly has been determined for cobaltous human hemoglobin in which iron(II) protoporphyrin IX is replaced by cobalt(II) protoporphyrin IX. The equilibrium parameters of the linkage system were determined by global nonlinear least-squares regression of oxygenation isotherms measured over a range of hemoglobin concentrations together with the deoxygenated dimer-tetramer assembly free energy determined independently from forward and reverse reaction rates. The total cooperative free energy of tetrameric cobalt hemoglobin (over all four binding steps) is found to be 1.84 (+/- 0.13) kcal, compared with the native ferrous hemoglobin value of 6.30 (+/- 0.14) kcal. Detailed investigation of stepwise cooperativity effects shows the following: (1) The largest change occurs at the first ligation step and is determined on model-independent grounds by knowledge of the intermediate subunit assembly free energies. (2) Cooperativity in the shape of the tetrameric isotherm occurs mainly during the middle two steps and is concomitant with the release of quaternary constraints. (3) Although evaluation of the pure tetrameric isotherm portrays identical binding affinity between the last two steps, this apparent noncooperativity is the result of a "hidden" oxygen affinity enhancement at the last step of 0.48 (+/- 0.12) kcal. This quaternary enhancement energy is revealed by the difference in subunit assembly free energies of the triply and fully ligated species and is manifested visually by the oxygenation isotherms at high versus low hemoglobin concentration. (4) Cobaltous hemoglobin dimers exhibit apparent anticooperativity of 0.49 (+/- 0.16) kcal (presumed to arise from heterogeneity of subunit affinities).(ABSTRACT TRUNCATED AT 250 WORDS)

Hemoglobins↗
PubMed1991

Managing prostatitis in the elderly.

Bacterial prostatitis is primarily a disease of elderly men, and it is the most common urinary tract infection seen in this age group. Urosepsis from prostatitis or prostatic abscess occurs less frequently than with urological manipulation, but must always be considered in elderly men with prostatitis. This article focuses on the diagnosis and antibiotic treatment of bacterial prostatitis in the elderly.

Acute Disease↗
PubMed1990

Infections in the hospitalized elderly.

Nosocomial infections are a particular problem among the elderly. Their cost is high mortality and a bill of $4 billion annually. The routine observation of a few simple aseptic practices will significantly blunt the impact of this health-care concern in our hospitals and nursing homes.

Aged↗
PubMed1990

Pneumonia syndromes: a clinical approach in the elderly.

Important in the pathogenesis of pneumonia in the elderly patient are chronic diseases, including diabetes mellitus, coronary artery disease, congestive heart failure, chronic obstructive pulmonary disease, and cerebrovascular disease. Also vital are the changes that take place in the immune system and mucociliary clearance mechanisms of the lung. The clinician should be aware of these risk factors, especially since the mortality rate of lower respiratory infections approaches 40% in these elderly patients. Treatment guidelines are included.

Aged↗
PubMed1987

Three-state combinatorial switching in hemoglobin tetramers: comparison between functional energetics and molecular structures.

In a previous study on cyanomethemoglobin the 10 tetrameric species (each with a unique combination of ligated and unligated subunits) were found to exhibit three distinct free energies of cooperative interaction. The distribution of these free energies among the partially ligated species is incompatible with a two-state mechanism of molecular switching and requires a minimum of three molecular structures with distinctly different free energies of heme-heme interaction. Ligand-linked transitions between the three cooperativity states were found to be "combinatorial"--i.e., dependent upon changes in both the number and specific configuration of bound ligands. Here we present results from two other chemical systems that mimic intermediate oxygenation states. In these systems the heme iron is replaced by manganese in certain of the subunits. We find the same distribution of cooperative free energies as reported for the cyanomethemoglobin system. These results demonstrate that the three-state combinatorial nature of cooperative switching is neither a special feature of the cyanomet reactions nor of the substitution of manganese for iron, but reflects a fundamental property of hemoglobin. These findings are compared with crystallographic structural results on partially ligated hemoglobins.

Energy Metabolism↗
PubMed1980

The binding of Gold(I) to metallothionein.

The binding of gold(I) to metallothionein, MT, has been unambiguously established by the reaction of Na2AuTM with purified horse kidney MT. Zinc was displaced more readily than cadmium although the latter could be displaced using large Au/Cd ratios. The metal exchange reactions were complete within 2 hr of mixing. Further evidence that such reactions might be physiologically significant were obtained by studying in vitro metal displacements in the liver cytol of in vivo metal treated rats: When Na2AuTM was added to the cytosol of rats administered CdCl2 in vivo, zinc, copper and cadmium were displaced in 2/1/1 ratios from the metallothionein fraction. The zinc and cadmium displacement provide direct evidence that the gold was binding to MT. Addition of Cd+2 to liver cytosol of gold-treated rats resulted in displacement of copper and zinc, but not gold, from the MT fractions. When liver MT is prepared from rats exposed to Au or Cd, the Cd/protein ratio increased during the preparation, but the Au/protein ratio decreased. The Mt-bound metals account for 95% of the cytosolic Cd but only 15%-30% of the cytosolic gold in these studies. Thus, the nonspecific binding of gold to MT in vivo should be considered as one aspect in its equilibration among protein binding sites, which include, inter alia, metallothionein. Gold was found to coelute with zinc and cadmium in the MT fraction of rat kidney cytosol, when both Cd and Na2AuTM were administered to the rats. The possible significance of gold binding to MT in the treatment of rheumatoid arthritis--chrysotherapy--is briefly discussed.

Animals↗