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Biomedical subjects

J Wendel

Publications and source records attributed to J Wendel.

At least 19 recordsLinked to original sources
PubMed2001

Strategic interaction among hospitals and nursing facilities: the efficiency effects of payment systems and vertical integration.

Rising post-acute care expenditures for Medicare transfer patients and increasing vertical integration between hospitals and nursing facilities raise questions about the links between payment system structure, the incentive for vertical integration and the impact on efficiency. In the United States, policy-makers are responding to these concerns by initiating prospective payments to nursing facilities, and are exploring the bundling of payments to hospitals. This paper develops a static profit-maximization model of the strategic interaction between the transferring hospital and a receiving nursing facility. This model suggests that the post-1984 system of prospective payment for hospital care, coupled with nursing facility payments that reimburse for services performed, induces inefficient under-provision of hospital services and encourages vertical integration. It further indicates that the extension of prospective payment to nursing facilities will not eliminate the incentive to vertically integrate, and will not result in efficient production unless such integration takes place. Bundling prospective payments for hospitals and nursing facilities will neither remove the incentive for vertical integration nor induce production efficiency without such vertical integration. However, bundled payment will induce efficient production, with or without vertical integration, if nursing facilities are reimbursed for services performed.

Aged↗
PubMed2000

Divergent evolution of plant NBS-LRR resistance gene homologues in dicot and cereal genomes.

The majority of plant disease resistance genes are members of very large multigene families. They encode structurally related proteins containing nucleotide binding site domains (NBS) and C-terminal leucine rich repeats (LRR). The N-terminal region of some resistance genes contain a short sequence called TIR with homology to the animal innate immunity factors, Toll and interleukin receptor-like genes. Only a few plant resistance genes have been functionally analyzed and the origin and evolution of plant resistance genes remain obscure. We have reconstructed gene phylogeny by exhaustive analysis of available genome and amplified NBS domain sequences. Our study shows that NBS domains faithfully predict whole gene structure and can be divided into two major groups. Group I NBS domains contain group-specific motifs that are always linked with the TIR sequence in the N terminus. Significantly, Group I NBS domains and their associated TIR domains are widely distributed in dicot species but were not detected in cereal databases. Furthermore, Group I specific NBS sequences were readily amplified from dicot genomic DNA but could not be amplified from cereal genomic DNA. In contrast, Group II NBS domains are always associated with putative coiled-coil domains in their N terminus and appear to be present throughout the angiosperms. These results suggest that the two main groups of resistance genes underwent divergent evolution in cereal and dicot genomes and imply that their cognate signaling pathways have diverged as well.

Amino Acid Sequence↗
PubMed1996

Dynamic modelling of the binding of substances to the conserved membrane-adjacent heptapeptide of the 15-residue C-terminal cytoplasmic fragment of mammalian dopamine D2 receptors.

Dynamic modelling was carried out on the binding in water of several substances to the conserved membrane-adjacent heptapeptide of the 15-residue C-terminal cytoplasmic fragment (C-tail) of mammalian dopamine D2 receptors, PheAsnIleGluPheArgLys. Particularly important in the establishment of binding pockets for ligands were the carboxyl, phenyl, guanidino, and epsilon-amino groups of the last 4 residues. A broad array of chemical structures was found to be potentially capable of binding to this site, among which were dopamine, dopamine D2 receptor agonists and antagonists, GABA, muscimol, GABA(B) receptor agonists and antagonists, homocamosine, and carnosine. Since the C-tail is critical for G protein binding, it is suggested that many naturally-occurring and synthetic substances may be modulators of activation of G proteins by G-coupled receptors.

Amino Acid Sequence↗
PubMed1996

Managing risk in a changing health care system.

This article examines the information requirements and other strategies needed to manage business and financial risk in health care organizations. The business and financial risk of providers in the changing health care market is defined. The major factors that are increasing risk are outlined, and strategies for measuring and managing risk are discussed. The interaction of business and financial risk is described, and strategic goals that will minimize the effect of this interaction are presented.

Capitation Fee↗
PubMed1994

Induction of labor with pulsatile oxytocin by a computer-controlled pump.

OBJECTIVE: The objective was to test the safety and efficacy of a pulsatile oxytocin infusion protocol in which a computer-controlled pump adjusts the oxytocin dose rate on the basis of uterine activity. STUDY DESIGN: A total of 358 women were enrolled in, and 310 completed, a prospective, randomized clinical trial comparing three protocols for the induction of labor with oxytocin: aggressively managed continuous infusion, conservatively managed continuous infusion, and computer-controlled pulsatile infusion. Results were analyzed with Student t and chi 2 "goodness-of-fit" tests. RESULTS: Mean doses of oxytocin in the group receiving pulsed oxytocin were approximately 20% of the dose rates in the continuous infusion protocols. All protocols effectively established labor in the majority of patients, although nulliparous women with unfavorable Bishop scores were more likely to fail to establish labor within a 24-hour period when treated with the aggressive continuous protocol. There were no differences in the rates of cesarean section, hyperstimulation, blood gases, or Apgar scores among the three treatment groups. CONCLUSIONS: Oxytocin dosage was minimized by use of a computer-controlled pump. With the exception of aggressively managed nulliparous women, there were no differences in the percentages of patients with successful inductions among the three protocols. The percentage of successful inductions was lower for aggressively managed nulliparous women than for other patient and protocol groups.

Adult↗
PubMed1994

Quality improvement--boon or boondoggle?

Is quality improvement (QI) reducing healthcare costs while improving patient care? Researchers find that QI has improved employee satisfaction and morale, but it was designed to do more. One solution is to use problem-solving techniques to help teams identify the level at which they want to address a problem, whether that be the subinstitutional, institutional, or system level. If QI is to fulfill its promise, skilled managers must create effective teams capable of defining and solving complex problems.

Efficiency, Organizational↗
PubMed1993

205Bi/206Bi cyclotron production from Pb-isotopes for absorption studies in humans.

Pb(p, xn) thick target excitation functions were measured in the energy range 10-38 MeV in order to optimize the production of isotopically pure radiobismuth from natPb, 206Pb, and 207Pb. Additionally, the decay of Po-isotopes from deuteron irradiation of natural bismuth (209Bi) was exploited for radiobismuth production. 205Bi was produced from 206Pb at 20 MeV with only 2% of 206Bi at 4 weeks post irradiation. Bismuth compounds as used in the treatment of peptic ulcer were labeled with 205Bi for absorption studies in animals and subjects.

Bismuth↗
PubMed1992

Bismuth absorption from 205Bi-labelled pharmaceutical bismuth compounds used in the treatment of peptic ulcer disease.

The absorption of bismuth from five 205Bi-labelled pharmaceutically used bismuth compounds was studied in man. From single oral doses of all compounds under investigation only less than 0.1% bismuth was absorbed and excreted with the urine. A significantly higher absorption was observed from the colloidal bismuth subcitrate (0.042% of the dose) and the basic bismuth gallate (0.038%) than from the basic bismuth salicylate, nitrate, and aluminate (0.005-0.002%). No retention of bismuth in the whole body was found from the single dose experiment. The biologic fast-term half-lives of absorbed bismuth were calculated to be 0.12 and 1.5 days.

Adult↗
PubMed1991

Bioavailability of bismuth from 205Bi-labelled pharmaceutical oral Bi-preparations in rats.

The bioavailability of 205Bi from various 205Bi-labelled pharmaceutical oral bismuth preparations was studied in rats. The intestinal absorption, calculated from 205Bi whole body retention and accumulated 205Bi urinary excretion, was small in general, but significantly higher (0.26-0.33% of dose) from oral bismuth citrates (basic bismuth citrate, colloidal bismuth subcitrate) as compared to basic bismuth nitrate, salicylate, gallate, and bismuth aluminate (0.04-0.11% of dose). After oral administration, the retained bismuth was mainly accumulated in the kidney, followed by bone, red blood cells and the lung. The whole body retention, faecal and urinary excretions of 205Bi were described by a three-compartment model. Biological 205Bi half-lives of 10, 36 and 295 h were derived in rats.

Administration, Oral↗
PubMed1990

Genetic and morphological analysis of a maize-teosinte F2 population: implications for the origin of maize.

Genes controlling the dramatic morphological differences between maize and its presumed progenitor (teosinte) were investigated in a maize-teosinte F2 population through the use of molecular markers. Results indicate that the key traits differentiating maize and teosinte are each under multigenic control, although for some traits, such as the number of ranks of cupules, the data are consistent with a mode of inheritance that would involve a single major locus plus several modifiers. For other traits, such as the presence/absence of the pedicellate spikelet, the data indicate multigenic inheritance with no single locus having a dramatically larger effect than the others. Results also indicate that the tunicate locus (Tu) had no major role in the origin of maize, despite previous opinion that it was involved. The major loci affecting the morphological differences between maize and teosinte are located on the first four chromosomes. The data suggest that the differences between teosinte and maize involve, in part, developmental modifications that enable (i) primary lateral inflorescences, which are programmed to develop into tassels (male) in teosinte, to become ears (female) in maize, and (ii) the expression of male secondary sex traits on a female background in maize. Similar changes were likely involved in the origin of maize.

Journal Article↗
PubMed1989

Major proteolytic fragments of the murine band 3 protein as obtained after in situ proteolysis.

Proteolytic fragments of murine band 3 were produced by exposure to extracellular chymotrypsin and intracellular trypsin. The ensuing proteolytic fragments were isolated, their N-terminal sequences were determined and their locations in the known amino acid sequence of murine band 3 established. Equivalents of the human 60, 35 and 17 kDa fragments were obtained through the cleavage sites were situated at locations that are not strictly homologous to the corresponding cleavage sites in human band 3, although all of them were near such sites. Exposure of the intact murine red cell to chymotrypsin leads to the formation of two fragments of 67 kDa and 41 kDa, which are equivalent to the 60 kDa and the 35 kDa fragments of the human band 3. Internal trypsin cleaves the chymotryptic 67 kDa fragment while the 41 kDa fragment appears essentially unaffected. The 67 kDa fragment is first degraded to 64 kDa, then further to 22 kDa and finally to 19 kDa. The anion transport inhibitor H2DIDS (4,4'-diisothiocyanodihydrostilbene-2,2'-disulfonate) combines with murine band 3 protein as it does with human band 3. Anion transport is maximally inhibited when 5.10(5) H2DIDS molecules per cell are bound to band 3. As in the human red cell, after exposure to high pH (9.0-9.5) of the H2DIDS-labeled, chymotryptically cleaved band 3 intramolecular cross-linking takes place. This joins the 67 and 41 kDa chymotryptic pieces together to form a peptide of the original molecular mass of band 3 of 108 kDa. If cross-linking is performed after additional tryptic cleavage, the 19 and 22 kDa pieces join together with 41 kDa pieces to form overlapping bands that cover the molecular weight range from 60 to 63 kDa.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1989

[Methods of diagnostic bone biopsy and its complications].

By the end of 1986 559 assessable biopsies had been taken at 3rd internal department. The authors continue the previous study performed at the department and suggest further methods for bioptic sampling enabling sampling of larger bone cylinders. They suggest several ways of bone trepan composition adjustment. The authors discuss and compare the incidence of complications associated with bone biopsy performance. They conclude that in inpatients bone biopsy performed in short-term general anaesthesia is a safe intervention.

Biopsy↗
PubMed1989

[Methodology of diagnostic bone biopsy and its complications].

By the end of 1986 559 assessable biopsies had been taken at 3rd internal department. The authors continue the previous study performed at the department and suggest further methods for bioptic sampling enabling sampling of larger bone cylinders. They suggest several ways of bone trepan composition adjustment. The authors discuss and compare the incidence of complications associated with bone biopsy performance. They conclude that in inpatients bone biopsy performed in short-term general anaesthesia is a safe intervention.

Biopsy↗
PubMedDate not supplied

Uncompensated hospital care: charitable mission or profitable business decision?

Provision of hospital uncompensated care is generally assumed to be adversely affected as increased healthcare competition decreases demand for compensated hospital services. Economic theory, however, suggests the question is more complex. Non-profit hospitals are assumed in this paper to maximize utility as a function of uncompensated care, subject to the constraint that revenues cover costs. For-profit hospitals, in contrast, are assumed to maximize profit while recognizing that failure to meet community expectations regarding provision of uncompensated care could negatively impact profits. Therefore, for-profit hospital supply of uncompensated care focuses on balancing the hospital's marginal costs and marginal benefits. These models predict that non-profit hospitals will respond to increased competition by reducing the supply of uncompensated care. In contrast, for-profit hospitals will increase the supply of uncompensated care when market demand decreases since the concurrent decrease in compensated care reduces the marginal cost of producing uncompensated care. The models also predict that for-profit hospitals will respond to changes in community expectations regarding the provision of uncompensated care.

California↗