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Biomedical subjects

R L Johnson

Publications and source records attributed to R L Johnson.

At least 289 records · Page 16Linked to original sources
PubMed1985

On the edge: will the drive for productivity push hospitals over?

In 1984, the first year under the prospective payment system, the federal government's expenditures for hospital care were lower than budgeted. If the savings were the result of improved hospital productivity spurred by economic competition, can hospitals repeat this success as government continues to ratchet down on Medicare payments and as competition increases? Several "lessons" about productivity explain how hospitals improved their bottom line and give indications of what may happen in the future: Organizations move rapidly to improve productivity when they are fiscally imperiled. Reducing labor costs to improve productivity has limited application. Productivity goals are of secondary importance to personnel who give direct patient care. Productivity norms must reflect health professionals' quality-of-care standards. Enhanced efficiency is not the cause of the productivity gains achieved so far. Rather, a major shift to more outpatient care has occurred. Inpatients, however, are now sicker and need more costly care. In the long run, health professionals' concern for providing high-quality care will take precedence over concerns about productivity and efficiency.

Cost Control↗
PubMed1984

Antagonist activity of phosphorus-containing glutamate analogues in the perforant path.

Two analogues of the amino acid L-2-amino-4-phosphonobutanoic acid (L-APB) were synthesized in order to test the hypothesis that the dianionic nature of the side chain is responsible for antagonism of excitatory synapses in the hippocampal perforant path. These compounds, DL-2-amino-4-(methylphosphino)-butanoic acid (DL-AMPB) and O-methylphosphonyl-L-serine (O-MPLS), possess singly-charged side chains and yet display antagonistic activity, illustrating that a dianionic charge on the side chain is not necessary for antagonism. Comparing structure-activity relationships for DL-AMPB, O-MPLS, L-APB, and O-phospho-L-serine (O-PLS), patterns of synaptic activity emerged which suggest that substitution of a methyl group for one of the phosphoryl hydroxyl groups lowers ligand potency in both medial and lateral pathways. Also, the nature of the atom at the gamma-position appears to alter the potency and degree of pathway selectivity of these ligands, a methylene unit imparting more potency and selectivity than an oxygen atom.

Aminobutyrates↗
PubMed1984

Inhibition of renin by substrate analogue inhibitors containing the olefinic amino acid 5(S)-amino-7-methyl-3(E)-octenoic acid.

The olefinic dipeptide 5(S)-amino-7-methyl-3(E)-octenoic acid (1) was synthesized and used to make the olefinic peptides Leu psi [E-CH = CH]Gly-Val-Phe-OCH3 (2) and His-Leu psi [E-CH = CH]Gly-Val-Phe-OCH3 (3). These olefinic peptides were found to exhibit renin inhibitory activity against both hog kidney renin and human amniotic renin that was comparable to the substrate analogue inhibitors Leu-Leu-Val-Phe-OCH3 and His-Leu-Leu-Val-Phe-OCH3.

Amino Acids↗
PubMed1984

Use of triphenylmethyl (trityl) amino protecting group in the synthesis of ketomethylene analogues of peptides.

The Grignard reagents of 2-(2-bromoethyl)-1,3-dioxane and 2-(2-bromoethyl)-1,3-dioxolane readily reacted with the 2-thiopyridyl ester of N-triphenylmethyl-L-leucine to give the ketone adducts 2-[3-oxo-4(S)-(triphenylmethyl) amino-6-methylheptyl]-1,3-dioxane (8a) and 2-[3-oxo-4(S)-(triphenylmethyl) amino-6-methylheptyl]-1,3-dioxolane (8b) in near quantitative yield. When 1 equiv. of the Grignard reagent of 2-(2-bromoethyl)-1,3 dioxane was used, the desired ketone adduct 8a was formed slowly but quantitatively. In contrast, when 2 equiv. of the Grignard reagent were used, the formation of ketone 8a was instantaneous. The triphenylmethyl protecting group was easily removed from 8a using dilute acid to give the amino ketone 2-[3-oxo-4(S)-amino-6-methylheptyl]-1,3-dioxane oxalate salt (9). This material served as a useful intermediate in the synthesis of the ketomethylene analogues of the peptides, Z-Pro-Leu-Gly-OH and Leu-Gly-Val-Phe-OCH3.

Ketones↗
PubMed1984

Glucose turnover rates in chronically catheterized non-pregnant and pregnant rabbits.

Glucose turnover rates have been measured in conscious, chronically catheterized, non-pregnant and pregnant rabbits. Non-pregnant rabbits were studied weekly for 4 wk. Pregnant animals were studied once while non-pregnant and then weekly for up to 4 wk during pregnancy. Glucose turnover rate was measured using a primed-constant infusion of [U-14C]glucose and [6-3H]glucose. The weight of the rabbits did not vary throughout the 4-5 wk of study in either the non-pregnant or pregnant group. Seven pregnant rabbits delivered pups which weighed an average of 61 g each. In non-pregnant rabbits, blood glucose concentration did not vary with time. In the pregnant rabbits, blood glucose concentration fell by the end of gestation to an average value of 74.6 +/- 2.7 mg/dl, significantly less (P less than 0.01) than the glucose concentration in the same animals before pregnancy, 88.2 +/- 2.4 mg/dl. The weight specific glucose turnover rate did not vary with time in either the non-pregnant (4.38 +/- 0.16 mg X min-1 X kg-1) or pregnant rabbits (3.89 +/- 0.29 mg X min-1 X kg-1). Blood glucose clearance did not change over time in the non-pregnant rabbits but did increase in the pregnant rabbits in late pregnancy. Blood glucose clearance was inversely related to the fall in blood glucose concentration.

Animals↗
PubMed1984

Some aspects of maternal metabolism throughout pregnancy in the conscious rabbit.

Studies of maternal metabolism during pregnancy have focused principally upon the latter half of gestation. However, maternal metabolic adaptations to pregnancy may occur at all stages of pregnancy. To study maternal metabolism throughout pregnancy, we developed a chronically catheterized rabbit model in which animals could be studied under conscious, stress-free conditions when nonpregnant and then serially throughout pregnancy. Anesthesia produced marked hyperglycemia. In contrast, chronic catheterization and daily handling did not affect blood concentrations of glucose, lactate, ketone bodies, or free fatty acids, or food intake. Glucose concentration decreased with pregnancy to a value at term equal to 85% of the prepregnancy value. Lactate concentration rose significantly in the second half of pregnancy but changes in free fatty acids and ketoacid levels were not significant. These results are discussed from a comparative physiologic point of view, emphasizing the unique aspects of rabbit metabolism during pregnancy and the importance of performing such studies under conscious, stress-free conditions.

Anesthesia↗
PubMed1984

CEO must have authority to coordinate governance, management, medical staff.

As hospitals attempt to survive in today's new competitive environment, they will find that the traditional organizational structure does not work. This structure can be characterized as a three-legged stool. Governance, management, and medical staff existed in relative harmony, with each able to attend to its own distinct, separate responsibilities. The medical staff regulated itself, the governing board had no serious difficulties in coping with the institution's finances, and the CEO was concerned solely with the physical plant and hospital personnel. In a riskless economic environment, this three-legged stool could remain stable. In the coming years,however, a hospital will need a clear-cut, identifiable leader if it is to survive. To centralize authority primarily in the CEO's hands will be a difficult step for nonprofit hospitals, particularly those sponsored by religious institutions, because of their tradition of operating much as a charitable social agency rather than a business. But this step must be taken, even to the extent of naming the CEO as chairman of the board, for a leader is required who has the authority to make quick decisions in the competitive marketplace. Timeliness is of strategic importance in such an environment, and governing boards increasingly will find it impossible to make timely decisions on a collective basis. Moreover, CEOs will have to coordinate the activities of management, medical staff, and the governing board. They will need to play a strong role in ensuring that target levels in DRG costs are met, and they will need the authority to mediate in issues in which the hospital's economic interests are pitted against physicians'.(ABSTRACT TRUNCATED AT 250 WORDS)

Governing Board↗
PubMed1984

Competition presents opportunity for not-for-profit systems.

Though they face similar challenges in adapting to a competitive environment, investor-owned and not-for-profit (NFP) health care systems react differently. The investor-owned strategy reflects a philosophy that regards patient care and economics with equal concern, while NFPs' management decisions are rooted in a tradition of community service. For-profit chains are perceived as more efficient than NFP chains because they respond to marketplace demand. Studies, however, show that while operating expenses are about the same, for-profits charge more per admission. On the other hand, NFP systems, by allowing affiliates to participate in service expansion decisions, are able to maintain lean corporate staffs and thereby minimize administrative and fiscal costs. The NFP organizational structure enforces economic discipline in a way that for-profit chains--where corporate staff alone make service decisions--cannot achieve. The major difference, of course, between for-profits and NFPs is in philosophy, not in management techniques. NFPs should communicate to the public their commitment to serve all patients and remind consumers that their charges are comparable with for-profits'. Developing a capitation plan would provide NFP systems another opportunity to emphasize their service orientation. An effective capitation plan is a means to influence the marketplace toward chain affiliates, since subscribers under the terms of the plan use contract hospitals and physicians. In addition to sufficient capital, such a venture requires expert management. NFP systems will have to offer incentives such as executive stock ownership plans to attract and keep top talent. In the future, management and governing boards must base strategic plans on the public's needs, attitudes, and economic status, not on myths about the competition.

Economic Competition↗
PubMed1984

Effects of anxiety-reducing hypnotic training on learning and reading-comprehension tasks.

The effect of anxiety-reducing hypnotic training on learning and reading-comprehension tasks was examined. Fifteen college students who reported having test-taking anxiety were randomly assigned to an experimental or a control group. The experimental group received hypnotic training to reduce anxiety prior to taking a learning and reading-comprehension test. No significant difference was found between the experimental and the control group on the simple-recall task. However, on the reading-comprehension test the experimental group scored significantly higher than the control group. Further examination of the total score revealed that the experimental group difference was due to superior performance on the inference items. There was no difference between groups on items that required the recall of information from the passage. These findings support the notion that hypnotic training may be useful to reduce anxiety and improve test performance.

Anxiety↗
PubMed1983

Structure - function relationships for gamma-substituted glutamate analogues on dentate granule cells.

We previously demonstrated in the Schaffer collateral-CA1 region of the hippocampus that bath-applied agonists could be distinguished from antagonists among a group of acidic amino acid analogues by extracellular recording techniques. Here we report the use of the extracellular signs of agonist activity for discerning agonists and antagonists among several gamma-substituted glutamate analogues tested in the perforant path. The two-pathway composition of the perforant path offers the advantage over CA1 in that pathway-specificity, a postulated characteristic of antagonists, may be tested. By extracellular recording, D- and L-homocysteic acid, L-serine-O-sulfate, and L-2-amino-4-(5-tetrazolyl)-butanoic acid [L-glutamate tetrazole] were identified as agonists, and all 4 analogues were more potent than L-glutamate for inhibiting synaptic field potentials. Two previously identified antagonists, L-2-amino-4-phosphonobutyric acid and L-O-phosphoserine, exhibited the pathway-specificity and inhibitory kinetics consistent with properties expected for antagonists; both compounds detected 3 perforant path components with the same rank in sensitivity, suggesting that they are acting on the same set of receptors.

Aminobutyrates↗
PubMed1983

Carcinoma of the esophagus twelve years after curative resection for carcinoma of the esophagus.

A patient is presented who developed a second squamous cell carcinoma of the esophagus twelve years after a curative esophagogastrectomy for a similar lesion in the proximal stomach. Factors predisposing to local recurrence at an esophageal anastomosis are reviewed. The long disease-free interval in this patient, however, strongly suggests a metachronous primary tumor rather than local recurrence.

Aged↗